PVA practice questions
NABCEP · PVA · 300 questions
Original practice questions for the NABCEP PV Associate (PVA) Exam exam, covering every domain of the official exam outline.
This course contains the use of artificial intelligence.
About the PVA exam
- Questions
- Not published on the pages read
- Passing score
- Scaled score of 65 required to pass (scaled scores; criterion-referenced, not curved)
- Format
- Exam based on the PVA Job Task Analysis; taken after NABCEP Associate Registered Training Provider course or Entry Level conversion. Question count, duration and price not published on the pages read.
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Safety (20%) · 60 questions
- An apprentice must verify 480-V AC disconnect voltage and 600-V DC string voltage on a bright rooftop with a digital multimeter rated for the task. Gloves, glasses, and a buddy are on site. Which safe use of electrical test equipment proves absence of voltage?
- A crew is augering footings for a small ground-mount at a former fuel depot now used as a park. The environmental report flags this corner for possible petroleum-impacted soil, the contract requires notifying the site contact before a flagged area is disturbed, and a storm drain inlet sits ten feet downhill of the hole. The auger brings up dark, oily soil that smells of fuel. Which excavation control should the crew apply before more soil is removed from that hole?
- A solar firm is writing its site safety plan for a steep-slope residential install with ladder access, attic work, and panel handling near a 240V service. The manager must cite the right authorities for falls, ladders, and electrical hazards. Which safety-plan statement best identifies the applicable safety regulations?
- A three-person crew is installing a 40-module array on a flat warehouse roof whose bare edges drop 6 m on all sides. Their route from the hoist to the array crosses three unguarded skylights, and the building's maintenance staff walk that route weekly without harness training. Which fall protection arrangement should be installed for this roof?
- An apprentice must cut strut and drill a weatherproof box on a windy rooftop where metal shavings fly, cords cross the walk path, and the panel edges are sharp while wearing gloves and glasses. Which hand and power tool safety practice best controls these cutting hazards?
- A two-person crew must clean dust from ground-mount modules reached by kneeling on a damp hillside near a pond, with slip and shock risks from hoses and cords. The foreman can reroute work to dry level carts. Which control choice applies the hierarchy of controls to this solar hazard?
- A two-person crew will cut aluminum rails with a chop saw on a sunny rooftop, drill into concrete for anchors, and then torque energized DC connectors in a combiner. Dust, noise, glare, cuts, and arc flash are all present. Which PPE selection best fits the combined eye, hand, ear, and arc hazards of this task?
- A service call finds a scorched combiner with melted insulation, a lingering burnt smell, and midday sun keeping the roof array live with no effective rapid-shutdown reset. The owner wants power back fast. Which assessment captures the risk of working on energized or faulty equipment including rapid shutdown?
- A PV service technician opens the van before a rooftop inspection and finds three issues: a fiberglass extension ladder with a deep gouge exposing fibers in one side rail, a fall-arrest lanyard with no legible inspection tag even though the employer's procedure requires one, and a GFCI extension cord whose strain relief is cracked near the plug. The customer is waiting and usable spares are already on the truck. Which pre-use inspection decision does this equipment condition require before work begins?
- A three-person crew starts a 25-module retrofit on a two-story shingle home with a skylight hole, ridge work near the eave edge, and morning dew on dark shingles. The lead holds a pre-job hazard talk. Which fall-hazard recognition guides the morning setup?
- You must lift six modules and rails to a second-story roof over a narrow side yard with a fence, kids next door, and gusty wind. Crew have ropes, a gin pole, and tool lanyards. Which hoisting, rigging, and tool-tethering method keeps the lift controlled and the ground clear?
- A three-person crew stages 24 modules, two rail bundles, and a case of lag screws for a 9.6 kW array on a shingled roof with rafters at 16 inches on center; the deck between rafters carries only light loads, and the ladder-to-array walk path must stay clear. Which staging layout best protects the roof and the crew?
- A two-person crew will clean terminals and torque connections on a vented lead-acid battery bank in a small energy closet with a sink nearby. Acid residue and arc risk are present. Which battery safety practice should the lead enforce first to follow insulated tools, face and eye protection, eyewash, and gloves?
- A two-person crew must move a 1,200-lb pallet of modules and an inverter across a sloped gravel lot to a commercial roof staging area using a rented forklift and a box truck with a liftgate. Which transport and heavy-equipment practice best protects people and gear during this move?
- You are lead for a one-day ground-mount install on an open lot next to a school walkway in Austin. Curious pedestrians cut through, and small tools sit near the trench. The safety plan calls for access control. Which control best meets the fencing or screening requirement to control site access?
- A technician must climb from a level concrete yard through a roof hatch onto a flat roof 3.2 m above to reset a string combiner. An exposed 208 V meter base sits 300 mm beside the hatch opening. On site are a 4.5 m fibreglass ladder, a 3.5 m fibreglass ladder and a 4.5 m aluminium ladder. Which ladder setup gives him safe access through the hatch?
- At a school parking-lot carport, a pallet of glass modules sits 40 feet from the array on level asphalt. Each module weighs 51 pounds, and the site lift plan requires two people to handle any item over 40 pounds. The finished rail sits 7 feet 6 inches above the pavement, so installers need an appropriately rated scissor lift to work at rail height rather than set the module from the ground. Crew leads also require installers to pivot with their feet instead of twisting at the waist. Which handling method meets all three requirements for setting these modules?
- A two-person crew arrives for a summer flat-roof service call at 95F with dark membrane, no shade, and wasps around the parapet conduit. One tech feels dizzy and the forecast shows afternoon lightning. Which hazard response best controls heat, weather, and animal risks?
- A crew is drilling 3/8-inch holes into a concrete foundation wall to hang rail brackets, and the site silica plan requires a vacuum shroud on any concrete drilling while site rules call for eye and hearing protection on rotary hammer work. The drill chart calls for hammer-rotation on concrete and rotation-only on wood and metal. Which drill setup covers every requirement for these foundation holes?
- A two-person crew services inverters on a low-slope warehouse roof, working about fifteen feet in from every edge. Six unprotected skylights sit inside the work area, the parapet is forty-two inches high, and the nearest engineered anchor is forty feet away along the north edge. Which fall protection system addresses the real exposure in this fifteen-foot work zone?
- An O&M technician opens an outdoor battery cabinet and finds a shallow puddle of electrolyte under one battery in a flooded deep-cycle bank. The concrete pad drains to a planted swale, the SDS requires a face shield, chemical goggles and acid-resistant gloves, and it calls for neutralizing the electrolyte with an alkaline absorbent before disposal. Which hazardous-materials response should the technician use for this electrolyte spill?
- Your crew must set ballasted racks on a dusty flat roof in summer heat where就不 saw-cutting concrete generates silica dust and workers face falls near the edge. Which control choice best applies the hierarchy of controls to this solar job-site hazard?
- Your crew installs modules on a distribution-center roof using a 60-foot horizontal lifeline with only a ladder and roof hatch for access, and EMS averages 20 minutes to reach this industrial park. The safety plan already lists first-aid kits, spill cleanup, responder access, and incident notification. Which emergency-response element is still missing for the fall hazard this crew faces?
- A foreman plans a two-story shingle-roof install requiring ladder access, fall protection, and work inside a live main panel to land a backfed breaker for a 10-kW system. Which identification of applicable safety regulations best guides this safety plan?
- Your crew arrives for a two-story shingle install with an uncovered skylight opening near the ridge and an unguarded eave leading edge where staging is planned. Morning huddle covers harnesses, covers, and rails. Which fall hazard control should the team identify first for leading edges and roof openings?
- Your crew will hand-dig an 18-in. deep AC trench across a side yard and auger four ground-mount piers near a driveway for a 6-kW array, and the homeowner mentions old fuel oil lines and soft fill soil. Which hazard control should the lead apply first to address digging hazards for trenching and footings?
- A two-person crew must lift three 45-lb modules and hand tools to a single-story roof edge with a public walkway below and gusts picking up. The lead wants controlled lifts and no dropped objects. Which hoisting, rigging and tool-tethering method best controls the lift?
- A crew arrives at a flat commercial roof to set two pallets of modules, a pallet of ballast blocks, and rails for a next-day install. The roof has marked walk paths, drains, and long spans between supports. Which staging plan best protects the roof with load distribution in mind?
- Your crew arrives for a 12-kW commercial rooftop job requiring extension ladders, fall protection harnesses, and a torque wrench, and the lead asks for a pre-use check before anyone climbs or lifts panels in breezy morning conditions. Which inspection of equipment before use best meets safe work practices?
- A 6-person crew starts a two-week commercial rooftop job with new hires, dusty panel cutting, and solvent cleaners on site, and the site lead must prove weekly safety compliance to the GC. Which safety-meeting and on-site document practice should the lead follow to satisfy the injury and illness program?
- A helper sets a 16-ft fiberglass extension ladder on compacted gravel to reach a 14-ft garage roof. The base sits 4 ft from the wall for a proper climbing angle, but the rails extend only about 1 ft above the roof edge. Which ladder setup makes stepping from the ladder onto the roof safe for the helper?
- Your two-person team must move palletized modules, a 90-kg inverter, and conduit across a muddy 15-kW farm site using a flatbed truck and hand cart where the path slopes gently and winds gust in the afternoon. Which method for transporting and moving heavy equipment and vehicles best protects people and gear?
- A two-person crew is sent to a rural ground-mount site on a January morning: minus 8 °C with a stiff wind, hoar frost on the steel rails they must climb that re-forms minutes after it is wiped, and a raccoon denning under the inverter pad they need to open. The supervisor has to brief the day's controls. Which control set covers the cold exposure, the frosted rails and the denning raccoon?
- A contractor is building a 40 kW ground-mount array on a vacant lot next to a school playground with foot traffic, curious teens, and evening trespass. The owner wants low upkeep and safe operation. Which site access control with fencing or screening best fits the safety plan?
- A technician opens a rooftop DC combiner at 2 p.m. to reset a tripped breaker. The string circuits run to a central inverter in fault mode with its AC disconnect open, while the utility still feeds the building. Which statement correctly describes the hazard at the combiner?
- You are assigned to drill rail lags in a hot attic, then help torque DC combiner terminations on a live 400-V rooftop disconnect nearby. The lead warns of dust, sharp flashing, loud tools, and arc-flash risk. Which PPE selection should you make for the task?
- A small contractor is writing a safety plan for a two-story home retrofit with roof work near a service drop and inverter terminations in a garage panel. The crew will use ladders, harnesses, and insulated tools with lockout steps. The supervisor wants each hazard tied to the right authority. Which safety regulation assignment correctly links OSHA and NFPA roles for fall and electrical hazards?
- An associate assists opening a residential AC disconnect before cleaning an inverter, the circuit feeds from a main panel across the garage, and tools and a ladder crowd the working space. Which de-energization, lockout/tagout and working-clearance practice best protects the crew?
- A two-person crew must move a 74 pound inverter from the delivery pallet across a gravel yard to an equipment wall, then lift it onto a bracket at chest height. Company policy requires two people or wheeled equipment above fifty pounds, and the loose gravel is too soft for the pallet jack. The lifting rule also says to keep the load close to the body and turn the feet instead of twisting. Which handling approach meets the weight limit, the surface condition, and the body-positioning rule for this move?
- A solar maintenance crew washes carport modules weekly with a concentrated caustic cleaner. Two workers still get stinging hands and red forearms even though they wear the gloves and goggles named on the safety data sheet, and the irritation mostly starts when they open the drum and dilute the concentrate. Handling training was refreshed last month. Which control should the safety officer prioritize to reduce the crew's chemical exposure?
- You lead orientation for a four-person crew starting a two-story home install with attic work, battery boxes with acid, and possible roof falls and arc faults. The general contractor asks what the crew will do if someone is hurt, exposed, or trapped aloft. Which emergency response plan scope should the safety lead present for first aid, hazmat, fire, and fall rescue?
- A pallet of flooded lead-acid batteries arrives at the warehouse and one case has cracked, spilling electrolyte onto the wooden pallet. The receiving lead and helper are already in acid-rated gloves and face shields, and the spill is small enough for the crew to handle. Cleanup must stay at the pallet so the dock keeps running, and the acid must be neutralized before anything is wiped up or discarded. Which spill-response step should they take first for the battery acid?
- A crew must trench 24 inches for conduit to a ground-mount footing area where old paint shop runoff stained soils and utility flags look faded. Overnight rain has left standing water in the open trench. Which digging hazard control should the lead enforce to address trenching, utilities, footings, and soil risks?
- An associate must verify zero voltage at a rooftop combiner after opening the disconnect, midday sun keeps modules live, and the meter was dropped last week on concrete. Which practice for using electrical test equipment safely best ensures a trustworthy reading?
- A crew is staging 24 modules, rail, and flashing for a rooftop array on a two-story office building. The structural drawing says staged loads must sit on the open-web joists at four feet on center, the roofing warranty requires protection boards under anything set on the membrane, and the two-foot strip along the eave is a cantilever rated only for foot traffic. Which staging arrangement satisfies the framing, warranty, and edge restrictions?
- A two-person crew stages a steep residential install with a leading-edge eave, an open skylight curb, and brittle shake areas that break underfoot near the ridge. Which assessment correctly identifies fall hazards such as leading edges and roof openings for this crew?
- During a walk-through of a 400-module commercial rooftop job, the general contractor's safety officer asks who attended last Friday's safety meeting and where the crew finds hazard information for the roof sealant. Which pair of records answers both the attendance and the hazard-location questions?
- During a service call a tech must shorten a length of steel strut that is only propped against the equipment rack. The truck has a 4-1/2 inch cordless angle grinder with a grinding disc installed, its guard rotated out of the way, plus a box of same-size cut-off wheels. How should the tech set up the angle grinder and the strut before cutting?
- A two-person crew mixes and pours six concrete piers for a ground-mount array on a hot morning. Wet mix splashes at ankle height, bagged mix puffs dust when opened, the mixer runs continuously, and cut rebar tails stand above every form. Which combination of PPE and site controls addresses every hazard present during this pour?
- A two-person crew arrives for a July rooftop survey in Arizona, 102F with high sun, no wind, and finds pigeons nesting under a prior array plus wasp activity at the eave. One tech feels dizzy and the tile is too hot to kneel on. Which control should the lead apply first to address environmental hazards from heat and animals?
- At noon an installer must service a home array where one combiner shows burn marks and the inverter display is dark. The roof is bright, the rapid shutdown switch is by the main panel, and the owner asks if the roof is now safe. Which electrical safety assessment explains the risk of energized or faulty equipment including rapid shutdown?
- You troubleshoot a daytime rooftop string with a suspected ground fault before opening the combiner, with the inverter still connected and conduit showing burn marks. The array stays live in sunlight and AC remains backfed. Which hazard assessment correctly identifies DC and AC shock, arc flash, and ground-fault risks?
- A two-person crew arrives for a home rooftop job with harnesses, a ladder, and a corded drill that sat in a damp truck overnight. The lead asks for a pre-use check before anyone climbs or starts drilling. Which pre-use inspection routine should the crew apply to confirm safe work practices?
- A technician must replace a blown bus fuse in a distribution panel at a fire station. The panel is fed both by the utility service and by a generator through an automatic transfer switch, and the crew has opened, locked, and tagged both handles. Which check proves the panel is de-energized before anyone touches a conductor?
- Your crew will stage a two-day home install on a busy corner lot where kids cut through the yard, pallets and ladders sit overnight, and the neighbor runs a daycare next door. Which site-access control should the safety plan require to limit public exposure during this work?
- A crew stages 50-pound modules from a floor stack onto a waist-high material lift for a two-story roof. The path is clear and dry, a coworker is free, and site rules require two people above 40 pounds, a squat lift from floor stacks, and pivoting the feet through the quarter turn at the lift. Which handling approach meets the weight and body-positioning rules for this job?
- During a battery retrofit in a garage, the crew finds a swollen lithium cabinet, a cracked lead-acid case with dried acid, plus sharp sheet-metal offcuts and dusty concrete cutting nearby. The schedule is tight and the homeowner is watching. Which handling sequence best controls chemical and physical hazards safely?
- A two-person crew must unload a 260-pound battery cabinet from a rental van parked on a gravel driveway that slopes down toward the street. The van carries a folding ramp, an appliance dolly, and wheel chocks, and no other help is on site. Which action best keeps the van and the heavy cabinet under control?
- An apprentice must help replace a swollen 48-V storage battery in a dim garage with old wiring, metal shelving, and no sink nearby. The lead wants acid, arc, and eye risks covered before covers come off. Which battery safety setup follows insulated tools, face and eye protection, eyewash, gloves?
- A foreman writes a one-page plan for a three-story retrofit where a worker uses a harness near a skylight, a forklift moves pallets, and old batteries leak in storage. Which element should the emergency response plan include to cover first aid, hazmat, fire, and fall rescue for this site?
Core Knowledge (20%) · 60 questions
- A homeowner with a 6-kW rooftop system wants phone alerts for low production and a monthly energy report, while the installer wants remote fault codes without a site visit. The site has Wi-Fi and a revenue-grade meter on the inverter. Which monitoring equipment function best meets both needs for this home?
- A training lab has four small demo boards: a fan wired straight to a module, a shed light with battery and no grid, a house array that shuts off with the grid, and a house array with battery backup. Which statement correctly distinguishes PV direct, stand-alone, grid-tied, and multimode systems?
- A homeowner has reliable grid power, wants daytime bill savings with net metering, has no batteries, and needs shutdown when the grid fails for lineworker safety. The trainee must label the design file correctly. Which system type label describes this battery-free grid-linked configuration?
- A new residential PV owner reports high bills despite a working inverter display showing power today. The O&M tech needs remote history of energy, alerts, and string trends to diagnose without a site visit. Which description best states the role of monitoring equipment in this system?
- A trainee confuses a fan wired straight to a module, a cabin with batteries and no grid, a suburban net-metered roof, and a suburban roof with backup batteries. Which concept check distinguishes PV direct, stand-alone, grid-tied, and multimode systems by storage and grid ties?
- A new O&M helper checks a 20-kW commercial rooftop where the owner wants phone alerts for low output, string-level fault location, and proof of monthly savings without opening electrical gear. Which monitoring equipment description best meets these visibility needs?
- On a ground-mount service call, an apprentice sees bare copper to frames, a lug to a ground rod, and a jumper between metal boxes and asks what each part does for fault safety. The lead must clarify paths without quoting code text. Which answer best distinguishes grounding and bonding elements EGC, GEC, electrode, and jumper?
- On a residential rooftop retrofit, the installer bonds module frames to rails and runs a wire from the rail to the main grounding bus, which ties to a ground rod. The lead confuses the rail wire with the rod wire. Which grounding and bonding distinction correctly names EGC, GEC, electrode, and bonding jumper for this system?
- A family on a reliable grid wants lower bills plus lights and fridge through short outages, keeps a small utility link, and can house a battery in the garage. Budget allows one inverter and storage. Which system type fits this backup-plus-savings customer scenario?
- A farm family wants daytime power for a remote pump with no utility lines, no need for night use, and the lowest cost and upkeep. A vendor proposed batteries and a backup generator. Which system type match fits this customer scenario with cost and maintenance limits?
- A trainee wires a residential rooftop system where module frames must link together, the inverter case needs fault protection, and a ground rod ties the system to earth through a continuous conductor with jumpers around lugs. Which grounding and bonding element choice correctly separates EGC, GEC, electrode and jumper?
- A rural clinic needs vaccine refrigeration through frequent multi-day grid outages, has space for batteries, and can fund storage for critical loads only. Fuel delivery is unreliable. Which system type match best fits the customer scenario for backup and daily solar use?
- A rural health clinic loses grid power twice each winter for 6-10 hours and needs vaccines refrigerated and lights on. It has rooftop PV but no storage and shuts down during outages. Which system feature should the associate describe first to explain energy security through reliability and resiliency?
- A new installer asks why a silicon module makes DC power in daylight with no moving parts. You explain the cell has p-type and n-type layers forming a junction, photons strike the silicon, and meter leads read voltage and current. Which description correctly explains the photovoltaic effect behind this reading?
- A new installer asks why a silicon module makes DC power with no moving parts during a toolbox talk in Denver. The crew works with crystalline modules rated near 40 Voc and wants the physics, not sales terms. Which statement correctly explains the photovoltaic effect for this entry-level crew?
- A rural clinic director worries about multi-day storm outages spoiling vaccines and closing exam rooms. The site has a grid-tied PV array with no storage, and staff ask how solar helps security. Which explanation correctly describes reliability and resiliency for this site?
- A new helper on a 8-kW home install asks why the modules produce DC power in full sun even though they stay relatively cool to the touch in a breeze. Which explanation of the photovoltaic effect best answers that question?
- A rural clinic with frequent evening outages considers a 25-kW PV array with battery storage to keep vaccines cold and lights on. Leaders ask how solar helps security beyond lower bills. Which explanation best describes reliability and resiliency for this clinic?
- During commissioning of a 6-kW residential string in Boise you read 240 Vdc and 20 Adc at the inverter input on a clear cool morning. The lead asks you to verify expected DC power and check consistency with meter readings. Which application of Ohm's law and power relationships correctly validates the operating point?
- A first-time buyer in a suburb asks a salesperson why neighbors added rooftop PV when grid rates keep rising and wildfire smoke fills skies each August. The home has good sun and net metering. Which explanation best links predictable cost and environmental benefit?
- A trainee measures a residential string at 380 V and 9 A at midday and must verify expected power and check whether a 10-A series fuse rating leaves safe margin before calling the lead. Which application of Ohm's law and power relationships best completes this check?
- A school board hesitates on a 200-kW rooftop PV bid because utility rates rose 4% yearly and parents ask about air quality near a gas plant. The system has 25-year performance coverage. Which benefit of predictable electricity cost and environmental gain should the associate explain first?
- A school board weighs a 100-kW rooftop to stabilize a tight operating budget and meet climate goals, asking what solar delivers beyond kilowatt-hours. Which explanation best captures predictable electricity cost and environmental benefit for this school?
- During commissioning of a 6-kW string inverter you measure 240 volts AC at the point of connection while the system exports 24 amps to a resistive test load. The lead wants power and circuit resistance confirmed from these readings. Which Ohm's law and power calculation gives the correct values?
- A homeowner with a 5-kW rooftop system says the monitoring app showed 4 kW at noon and 20 kWh for the day, and asks why the two numbers differ when both describe system output on a clear day with no outage. Which explanation correctly distinguishes power (W) from energy (Wh) for this PV system?
- A homeowner sees a 6-kW array rating and a monitor showing 24 kWh made Tuesday, and asks why the numbers differ while comparing a 300-W panel to a battery storing 10 kWh. Which statement correctly distinguishes power (W) from energy (Wh) for this customer?
- A suburban homeowner with high daytime air-conditioning use and frequent evening outages asks how a 7-kW rooftop system without storage helps bills and the grid on sunny afternoons. Which description should the associate give to explain economic benefits and distributed generation?
- A homeowner asks why rooftop solar helps household bills and the local grid when a large distant plant could make cheaper power. She has high afternoon peak rates and frequent summer congestion. Which economic benefit best describes distributed generation for this customer?
- A homeowner asks why rooftop solar plus staying tied to the grid helps household bills and the local feeder with evening peaks and daytime solar surplus. Which description of economic benefits and distributed generation answers correctly?
- A new salesperson tells a homeowner with a 400 W module quote that the system will make 6,000 W per day, mixing ratings and bills that show kWh use. The manager asks for a correction before proposals go out. Which statement correctly distinguishes power (W) from energy (Wh)?
- A new hire asks why a 400-W glass-backsheet module on rails needs clamps at set zones and a small gap to the roof. Which description should the trainer give to describe PV modules and mounting structures?
- A sales designer must explain to a client why two same-wattage quotes differ when one uses glass-backsheet modules on rail mounts and the other uses glass-glass modules on shared-rail low-slope mounts. Which description of PV modules and mounting structures is correct?
- A ground-mount client worries about wind uplift, module cracking, and future swaps, asking how panels and racks share loads and allow service. Which description of PV modules and mounting structures answers best?
- During a rooftop O&M visit, one string in a 24-module array reports zero current at the combiner while its neighbors read normal. The array is in full sun with the DC disconnect closed, and a meter across that string's inline fuse reads a distinct voltage while the same test across a healthy fuse reads almost nothing. Which fault do the readings pinpoint at that fuse?
- A technician measures a residential string at midday and reads 410 V open-circuit as expected, but voltage sags sharply when loaded and one connector feels warm. Resistance across that section reads high. Which interpretation of voltage, current, resistance and impedance measurements best explains the readings?
- An apprentice checks two identical inline fuse holders on a DC string carrying 9 A at midday: across one the meter reads 0.02 V and across the other 2.8 V, while both points read 0 V after sunset when the array produces nothing. Which interpretation of these voltage-drop readings is best supported?
- A homeowner has partial chimney shade, wants panel-level monitoring, and may add batteries later for backup. The sales rep offers string, central, micro, and multimode choices. Which inverter comparison should the associate present to match shade tolerance and future battery backup?
- A developer compares options for a 600-kW open-field plant on one flat site with uniform sun, three-phase service, and a central electrical room for easy service access. Which inverter comparison correctly matches string, micro, multimode, and central inverters to this project?
- A new sales rep shadows you on a home with rooftop DC strings feeding an inverter that exports AC to the panel, asking why both types exist. The inverter display shows DC volts in and AC volts out. Which comparison of AC and DC behavior should the associate give to explain solar power flow?
- A trainee sees DC from modules entering a string inverter and AC leaving to a home panel, the crew debates why an inverter is needed, and the foreman asks for a clear distinction for safety and metering. Which statement comparing AC and DC best guides safe handling and system understanding?
- An entry-level tech is checking a working rooftop string wired to a string inverter that feeds a home panel. Morning readings show steady polarity at the module leads and a cycling sine at the panel feed. The lead asks why two meters are needed for one sun source. Which electrical comparison of AC and DC correctly explains the readings and test approach?
- A builder is comparing bids for eight townhomes with mixed roof faces, light chimney shade, and a request for panel-level data with no batteries and minimal single-point outage risk. The lots share one service trench. Which inverter comparison should the designer present to match string, micro, multimode, and central types to this need?
- A retrofit adds a shaded dormer string to a high-voltage residential inverter, and the local code requires module-level rapid shutdown with shade-tolerant harvest on the affected roof face. Which power electronics choice correctly explains rapid shutdown devices and DC-to-DC converters for this need?
- A trainee is assigned to a small home with a 120/240V panel and later to a shop with a 208V three-phase panel. Both sites have PV breakers, but conductor counts, neutral use, and phase relationships differ. The mentor asks what service is present before landing wires. Which circuit comparison among single-phase, split-phase, and three-phase best identifies each service?
- An associate must explain service options to a homeowner with 120-V lights and 240-V well pump, and to a shop with 208-V motors fed from three hot legs. The meter tags are unclear. Which circuit comparison of single-phase, split-phase, and three-phase supply should the associate give to guide equipment choice?
- A service tech is upgrading a 6-kW string array that needs NEC rapid shutdown at the modules and has one chimney-shaded string losing morning output, with no batteries planned and the existing inverter kept. Which power electronics choice explains rapid shutdown devices and DC-to-DC converters for this retrofit?
- A junior designer reviews three services: a small cabin with 120 V lighting, a suburban home with 120/240 V appliances, and a warehouse with 208 V motors, and must explain wiring and power differences to the crew. Which comparison of single-phase, split-phase and three-phase circuits best fits each site?
- A rooftop crew wires a 12-module string to a string inverter where the plan calls for module-level rapid shutdown and one shaded module needs voltage boosting. Which power-electronics choice should the associate verify to meet shutdown and DC-to-DC conversion needs?
- A trainee tests a small off-grid demo with four identical 40-V, 10-A modules. First all four are wired in series, then rewired as two series strings of two modules in parallel. Which paired circuit value correctly shows the series versus parallel result for comparison?
- A small farm shop runs a grid-tied solar array with a battery bank and a smart panel for freezers and well pumps. The owner asks why power stays on after sunset and why freezers stay cold while shop tools shut off during a low-charge event. Which statement best describes energy storage and load control roles?
- You wire four identical 42-V open-circuit, 11-A short-circuit modules for a small off-grid test, first all in series then all in parallel, using ideal values and ignoring losses. The charge controller has strict voltage and current limits. Which calculated result correctly shows series versus parallel circuit values?
- A homeowner's hybrid inverter provides backup to part of a 200 A main panel from a fully charged battery with 10 kWh usable capacity, and the budget leaves no room for extra battery capacity. During evening outages the inverter carries the 4.5 kW water heater and 7 kW EV charger without any power limit, yet the battery runs dry in about an hour and the fridge goes dark. The fridge, lights, and router together average 0.5 kW, and outages typically last 10 hours until sunrise. Which load-control change will keep the fridge and other critical loads powered until sunrise?
- On a shed demo board a trainer has three identical 42-V open-circuit, 9-A short-circuit modules feeding one fused homerun. Trainees must predict meter readings before covering and uncovering modules. Which series versus parallel circuit calculation correctly predicts total voltage and current for the demo?
- A rural clinic wants lights and vaccine refrigeration to ride through nightly outages, with daytime PV often exceeding demand and staff forgetting to turn off extra loads. The designer proposes batteries plus automated switching. Which energy storage and load control role description should the associate use to explain system functionality?
- An apprentice wires a small grid-tied rooftop system from array to main service and asks what each box and run does. The run uses roof conduit to a fused disconnect, then to the main panelboard with a backfed breaker and an overcurrent device sized for the wire. Which description correctly identifies balance-of-system parts?
- During a class demo an instructor faults a 48-V battery rack where the grounded conductor and the metal case bonds look identical to students. Which explanation correctly distinguishes system grounding from equipment grounding and bonding for this setup?
- You explain to a new installer why a small string-inverter home has a grounded DC conductor tied to earth and also green equipment wires bonding frames, rails, and enclosures. The site has lightning exposure and a service grounding electrode. Which explanation correctly distinguishes system versus equipment grounding and bonding?
- An associate is labeling a residential supply-side job with modules, inverter, and battery already tagged, and must identify the remaining balance-of-system parts for the as-built: main panelboard, fused disconnect, metal conduit run, PV conductors, and breaker protection. Which statement best identifies balance-of-system parts and their roles?
- A helper is kitting parts for a 20-kW rooftop to inverter run and asks which items count as balance-of-system beyond modules and inverter. The run needs a main tie-in, service isolation, raceway, wiring, and fault protection. Which balance-of-system grouping should the lead identify for panelboards, disconnects, conduit, conductors, and overcurrent devices?
- During a walk-through at a small warehouse PV system with a grounded DC array, a trainee traces two conductors landing on the grounding bar at the system's designated bonding point: a green wire from the metal combiner enclosure, and the array's negative conductor, marked with white tape. The electrician says one connection is equipment grounding and the other is system grounding. Which statement correctly describes what each connection does for safety and normal operation?
Sales and Economics (10%) · 30 questions
- A homeowner in a time-of-use area uses 6 kWh overnight for fridge, lights, Wi-Fi and phone charging and wants that load covered plus next-day cloudy backup for the same loads. The sales rep has meter data and a critical-load list. Which storage estimating method best sizes usable capacity for self-consumption and load shifting?
- A homeowner with good tax liability, a neighbor with little taxable income, and a third buyer short on cash all ask about a 6-kW quote. The state offers an upfront rebate, a tax credit that offsets only tax owed, and a low-rate loan program. Which economic comparison explains tax credits, rebates, and low-interest loans for each buyer?
- A café tenant has her landlord's written approval to install solar on the roof. She wants to keep her cash for a new oven, see a solar cost that stays steady through cloudy weeks, and end the term with no equipment left to own or maintain. Which financing option meets all three goals?
- A sales rep gets a web lead for a 9 kW home system: a renter in a shaded duplex wants zero-down purchase, quick install, and HOA approval handled. The manager asks if the lead is qualified to advance. Which qualification review covers location, utility, and ownership needs?
- Three neighbors request quotes: one tracks payback and bill savings closely, one wants low carbon and clean air, one wants backup during outages and control over rates. Bills, shade, and roofs are similar. Which qualifying summary identifies each customer motivation for financial, environmental, and energy-choice value?
- A salesperson is preparing a preliminary 8-kW home estimate where the customer wants full offset and fast install. The utility caps system size to annual use, needs an interconnection application, and requires an accessible lockable AC disconnect. Which utility interconnection requirement must the estimate recognize to stay valid?
- A family with 9,400 kWh of bills last year plans to buy an EV in six months and runs most loads evenings with higher summer cooling. They want a fair rooftop estimate now. Which preliminary estimating method should the associate use to account for current and anticipated usage and daily/seasonal profile?
- A homeowner in Raleigh wants a quick quote for a 7-kW roof system. The south roof is 18 years old with worn shingles, a 35-degree pitch, and a tall oak shading it until 11 a.m. The west roof is newer and open. Which preliminary system estimate best assesses shading, roof type and age, orientation, and pitch?
- A sales trainee must qualify three leads: a 8-kW home with net billing, a 250-kW warehouse with demand charges, and a 100-MW field with a power purchase contract. The trainee mixes up approval paths and sales cycles. Which market-segment distinction best organizes these PV opportunities?
- A 250-kW ground-mount array for a school district needs predictable budgeting for panel washing, inverter checks, mowing, and fast response if an inverter trips offline during classes. Which service-contract approach best covers inspection, cleaning, and vegetation work for this customer?
- A sales associate meets a family with high summer bills, a pool pump, and gas heat. They bring 12 months of electric bills showing kWh use by month, peak demand, rate plan, and net usage notes. Which bill review best qualifies the customer for a PV proposal?
- A homeowner compares a 7-kW cash purchase versus a high-interest loan while the utility projects steady annual rate hikes. They ask why payback shifts with money cost and bill growth. Which explanation best shows how financing cost and utility rate inflation affect payback?
- A sales rep is preparing a preliminary estimate for a 9-kW home system in a neighborhood with a strict municipal utility, the customer wants net metering, and the install is six weeks out. Which utility interconnection requirement should the estimator recognize first to keep the proposal realistic?
- A suburban client with a 9-kW system, 1:1 export credits, state SREC sales, and a utility battery dispatch offer asks where extra income beyond lowering the bill can come from. Daytime exports are steady and evening peaks pay bonuses. Which revenue opportunity should the advisor explain for dispatchable export income?
- A sales rep quotes a 25-year rooftop system for a home with 18-year-old asphalt shingles and an existing 11-year-old string inverter the owner wants to keep. The customer wants no surprise costs. Which maintenance cost forecast best anticipates equipment and roof replacement costs?
- A customer with high late-afternoon use faces time-of-use rates with pricey 4-9 pm power, a monthly demand charge, and net metering that credits surplus at a lower rate. The seller must size self-use and export timing. Which rate-structure interpretation guides the preliminary estimate?
- A sales rep is quoting a 7-kW home system where the customer compares two bids with different totals and asks what actually drives the final price beyond the panels and inverter on a simple shingle roof with no battery or trenching. Which identification of system price components best answers the cost question?
- A couple requests a 5-kW quote: one partner wants lower utility bills and outage ride-through for a home office, the other wants lower carbon and supporting local clean power. Budget is tight and the roof has minor shading. Which qualifying question should the associate ask to identify customer motivations?
- A sales rep meets a homeowner with good credit, steady tax liability, and limited cash for a 6 kW rooftop system. The state offers an upfront rebate, the federal program offers a credit against taxes owed, and a local bank offers a low-rate loan. The customer asks how each dollar actually helps. Which economics comparison of tax credits, rebates, and low-interest loans best guides the purchase choice?
- A sales rep is sizing a 1,800-sq-ft home that used 10,800 kWh last year, runs a pool pump mostly in summer afternoons, and plans to add an EV next spring with night charging. The utility has high summer time-of-use rates. Which preliminary system estimate method accounts for current and anticipated usage with daily and seasonal profile?
- A caller wants a quote for a suburban home with a south roof, mentioning high bills, a co-op utility, and that they rent with plans to move in two years. Your manager needs only viable leads passed to design. Which qualifying check on location, utility, and ownership should the sales associate complete before a site visit?
- A small bakery pays high afternoon demand fees and faces evening outages, and asks if batteries save money beyond solar kWh. Load data show a sharp 4-7 p.m. peak. Which storage economics should the associate explain to show avoided cost and peak reduction value?
- A sales trainee has three leads: a 8 kW home roof, a 250 kW retail store roof with demand charges, and a 50 MW fenced field selling to a utility, each with different buyers, permits, and interconnection paths. Which distinction among PV market segments best guides the sales approach for these leads?
- A rural customer wants two days of backup for 8 kWh per day of critical loads plus daytime self-consumption, with limited roof space and frequent evening outages. Which preliminary estimate correctly sizes storage needs for backup load, autonomy, self-consumption, and load shifting?
- A salesperson is building a preliminary production estimate during a home visit in the Northern Hemisphere. The array will fit on only one plane: the 6-year-old asphalt shingle roof has a 6:12 south face shaded only over a small area by a chimney from 4 to 6 p.m., while the detached garage offers an unshaded 5:12 east face. Which roof plane should anchor the preliminary production estimate for the array?
- A homeowner with high evening use and a sunny roof asks why two neighbors with same-size systems have very different bills under different utilities. One has net metering, one has time of use with low midday credit, and a small shop faces demand charges. Which rate-structure interpretation should the associate give for a preliminary system estimate?
- A homeowner compares two quotes for the same 8-kW system with identical production: one cash purchase and one high-interest loan, while the local utility filed for multi-year rate hikes. Which statement correctly explains how financing cost and utility rate inflation affect payback for this choice?
- A sales rep must explain a 7-kW home quote to owners comparing two bids with different totals but similar panel counts. The owners ask what actually drives the installed price. Which breakdown correctly identifies system price components for the economics comparison?
- A homeowner is quoted a 8-kW rooftop system with a 25-year module performance promise, a 12-year string inverter warranty, and first-year savings that assume no output change. She plans to stay 20 years and wants true lifetime cost. Which economic assumption correctly accounts for degradation, replacement, and warranty limits?
- You qualify a homeowner with a 12-month utility bill showing kWh use by month, peak demand charges, time-of-use periods, and net-metering credits with rising evening rates. They want bill savings and right-sized solar plus possible batteries. Which utility-bill review best supplies useful data to size and value the project?
Design (18.3%) · 55 questions
- A homeowner in a zoned city wants a 7-kW rooftop system that will export power. The city requires a building and electrical permit, the utility requires an interconnection application, and power cannot flow until final sign-off. Which AHJ permitting, utility, and inspection sequence meets requirements?
- You are sizing a home with 9.6 kW DC of modules paired to a 7.6 kW AC inverter for a south roof with no shade and a tight budget. The inverter max DC input and voltage window both pass. Which compatibility check confirms the DC:AC ratio supports expected clipping and output?
- A technician commissions a ground-mount array on a hot July afternoon and records each string's voltage at the open terminals before the DC disconnect closes. Every string reads several volts below the module datasheet's listed open-circuit voltage, while connections and string counts verify as built. Which factor explains the lower open-circuit voltage readings?
- You are sizing a 9.6-kW DC rooftop array of south-facing modules paired with an 7.6-kW string inverter for a home with steady midday loads. The module specs fit the inverter MPPT voltage window and the max input current is not exceeded. Which inverter compatibility check confirms an acceptable DC:AC ratio for this design?
- A designer reviews two 400 W datasheets at standard test conditions for a 150 V charge controller limit in cold weather. Both show similar power but different open-circuit voltage and short-circuit current values on the label. Which reading of module specs guides the string sizing choice?
- A 9 kW home retrofit in a historic district needs a building permit, utility interconnection approval, and final sign-off before permission to operate. In this jurisdiction the utility reviews an interconnection application only after the AHJ approves the plans, its approval is required before construction, and the AHJ's final inspection must pass before anyone energizes. The designer must explain the sequence and who enforces each step. Which explanation best describes permitting, utility, and AHJ inspection requirements?
- An installer on a duplex roof finds two rail splice kits, unclear torque marks, and a wrinkled quick-start sheet that conflicts with memory. The inspector arrives in one hour with strict labeling checks. Which use of datasheets and manuals resolves the conflict correctly?
- A designer compares two 10-kW bids in a hot, dusty valley with rare rain, nearby almond harvest dust, and 105°F summer peaks. Both use the same modules and tilt. Which design adjustment best accounts for weather and soiling effects on performance?
- A 50 kW ground array in a dusty farm area faces hot summers, winter snow, and seasonal pollen that coats modules and raises cell heat. The designer must adjust expected yield for climate losses. Which design allowance best accounts for weather and soiling effects?
- You get a permit set for a 9-kW home showing a north arrow, property lines, a 3-ft ridge setback, vent locations, and two subarrays with string labels. The foreman asks for rail spans and wire routing confirmation. Which plan-reading task extracts site plans and array layouts for the install?
- A designer is adapting a rail kit the manufacturer ships for landscape rows to a barn roof where the modules will hang in portrait. The racking manual lists permitted orientations, clamp zones and rated loads, while the module datasheet adds frame depth and weight. Which three racking-manual checks must the designer confirm before releasing the layout to the crew?
- A ground-mount crew is staking row spacing for a 60-module array. Sheet A-1, the site plan, dimensions the rows at 12 feet from a scaled dimension string, and its title block notes that enlarged layouts and details govern and that scaling from that sheet is prohibited. Sheet A-4 is labeled 'Enlarged array layout' and dimensions the rows at 14 feet with rows running east to west, while detail M-1 shows 15-foot spacing for rows running north to south. This job's rows run east to west. Which source should the crew stake for this job's row spacing?
- A small metal fabrication shop has approved a 30 kW rooftop array on its 480Y/277 V, three-phase, 60 Hz service, and the designer has reserved a 100 A breaker space for the inverter in the main switchboard. A low-cost unit in stock lists 208 V three-phase output, 80 A continuous output, 60 Hz, and 150% surge for 10 seconds. Which inverter specification check determines whether this unit may be connected directly to the shop service?
- You are staging material for a 18-kW commercial rooftop using the permit plan set. The one-line shows the service, inverter, and AC disconnect, while a separate string diagram details modules per string, homeruns, and combiner inputs. The foreman asks what to pull from the string diagram for wire pulls. Which use of plan-set diagrams guides your wire pull correctly?
- You review permit plans for a 40-kW commercial rooftop with three inverters and 12 strings where crews confuse conduit runs, phase balance, and string polarity. The set has one-line, three-line, and string wiring sheets. Which diagram interpretation best assigns each sheet to its troubleshooting use?
- A designer must compare two small commercial sites: a sunny desert roof with 5.8 peak sun hours and a cloudy coastal roof with 3.2 peak sun hours using the same 10-kW array. Which application of peak sun hours should the designer use to predict the difference in daily performance?
- A designer must pair a single-phase residential string inverter with a 120/240V home service where the utility holds 60 Hz and the owner runs a well pump that draws a brief high inrush on startup. Which inverter specification check best confirms voltage, current, frequency, and surge compatibility?
- A designer in Albuquerque compares two fixed 8-kW proposals for a school: Site A averages 6.2 peak sun hours with light soiling, and Site B averages 4.8 peak sun hours with clear access. Both use the same gear and tilt. Which use of peak sun hours best predicts relative energy for design and performance?
- You are pulling DC homeruns in rooftop conduit for a 10-kW home where the attic reaches high heat, the conduit sits in full sun on the roof, and one raceway transitions through a damp crawlspace. The plan calls for 90C-rated insulation with wet-location and sunlight resistance. Which conductor choice meets temperature, ampacity, UV, and moisture needs?
- A designer is assessing the existing service equipment at a small bakery converted from a 1965 farmhouse before a 10.4 kW array is permitted. The meter-main is a listed 150 A, 120/240 V unit with a legible nameplate and an undamaged exterior. Inside the load center fed from it, the wire insulation at two breaker lugs is melted and the bus behind them is heat-discolored, while four breaker spaces remain free. Which service equipment finding must be corrected before the PV interconnection equipment is added?
- A designer in Portland must place 24 modules on a split roof where a chimney shades the lower west section from 2 to 5 p.m. and a maple shades the east edge in the morning. Production modeling is required for the permit. Which shading analysis best informs layout and energy estimates for design and performance?
- You are checking a residential plan set for exposed rooftop source circuits in conduit on a hot dark roof that stays wet and sunlit. Notes call for continuous current, high ambient derate, and wet location use. Which conductor selection meets temperature rating, ampacity, UV and moisture requirements?
- A site survey of a 1990s house shows a 200 A service panel with a 225 A bus rating, ten free breaker spaces, and a rust-free enclosure. The homeowner wants a 9.6 kW array whose inverter output breaker is 40 A. Which evaluation determines whether this load-side connection fits the panel's busbar capacity?
- A designer is laying out a 8-kW home array where a tall chimney shades the lower west roof from 3-5 pm and a neighbor tree shades the east roof until 9 am. Year-round production matters most to the owner. Which shading analysis result should guide final module placement?
- At a pre-install huddle for a 150-kW ground-mount site, the crew lead points to a circle on the array plan marked '3 / S-501' with an arrow at a pier. The drawing index splits sheets into E-series and S-series, and the general notes require embeds to be verified before concrete. Which sheet should the crew lead open to see the pier's anchor bolts and rebar?
- A designer is laying out a 7-kW fixed roof array for a suburban home at 40 degrees north latitude with a low-slope hip roof, light tree shade to the east, and a customer wanting best yearly energy. Which array tilt and azimuth choice should the designer recommend for annual performance?
- A homeowner wants overnight backup for a fridge, lights, WiFi, and a small well pump during 4-hour outages, plus daily time-of-use shifting. Two batteries are quoted with different kWh, kW, and inverter pairings. Which evaluation best matches storage system specs to the need?
- A junior installer is fitting rails on a 96-module ground-mount array. At every post-to-rail joint the layout sheet shows a circle split by a horizontal line, with 4 above it and S2 below. The set also holds a site plan, an equipment schedule and an electrical single-line, and she needs to see how the rail seats in the post cap and how the splice is made. Which sheet does that callout point her to?
- A designer must place a 6-kW fixed array on a low-slope commercial roof in the northern hemisphere with room to face south, southeast or southwest and tilt 5, 20 or 35 degrees while avoiding row shading. Which tilt and azimuth choice maximizes annual energy?
- A homeowner wants a 10-kWh-class wall battery for evening lights, fridge, and internet through short outages, AC-coupled to an existing 6-kW inverter on a 200-A panel. Which evaluation should the associate perform to compare storage system specs?
- A new designer assembled a 11-kW residential rooftop packet with datasheets, a single-line diagram, site plan, and structural letter, and the town reviewer returned it asking for the missing submittal forms and proof of utility review on a standard home with no variance needed. Which identification of permit documents best completes the application?
- A proposal for a 15-kW rooftop system promises 22 MWh per year, yet the site has high summer heat, long wire runs, dusty air, and a shaded parapet, and the client asks why modeled output is lower. Which derating and system-loss explanation should the designer give to justify the adjusted yield?
- A designer must choose modules, inverters, and racking for a permitted home system that the inspector and utility will approve. Suppliers offer mixed listed and unlisted deals. Which recognition of NRTL listing and product safety standards best guides selection?
- A designer prepares a permit package for an 8-kW home rooftop system with a supply-side tap. The city plan check asks for layout, wiring, and safety labels in one submittal. Which permit document package should the designer submit to show code-compliant electrical layout?
- A designer models an 8-kW rooftop array rated at STC for a dusty site with long DC runs and a hot attic. Notes list soiling loss, wiring voltage drop, elevated cell temperature, and published inverter efficiency. Which sizing adjustment correctly applies derating factors and system losses to predict output?
- A designer is reviewing cut sheets for a 9-kW home bid using listed modules, a listed string inverter, and listed racking on a city permit that requires third-party safety proof. One vendor offers cheaper gear marked CE only with no NRTL mark. Which equipment specification choice confirms NRTL listing and product safety standards?
- A drafter is building the load summary for a solar canopy at a transit center, where steel posts sit on concrete piers, tool totes are staged on the beams during the install, and backfill is compacted around each pier. Buses roll across a joint in the pavement beside the posts all day. Which line item should the drafter flag as the dynamic load on this structure?
- A homeowner is quoted a 7-kW DC array in a location averaging 5 peak sun hours daily, with an expected performance ratio of 0.78 after all losses and a south-facing shade-free roof. Which calculation correctly estimates energy production and efficiency for this proposed system?
- A design team is permitting a 15-kW residential array on a mountain home at 7,500 ft with 60-psf ground snow, 120-mph wind exposure, and a known seismic zone on composite shingles. The AHJ wants stamped racking proof. Which location-load review should the designer require to approve the racking and attachment plan?
- You size racking for a lakefront home with open wind fetch, heavy lake-effect snow, and a mapped quake zone, using flush-mount rails on comp shingles. The building office flags structural review. Which location-load review for wind, snow, and seismic forces should the designer document for the racking choice?
- A designer must confirm whether a proposed 15 kW DC array paired with a 12 kW inverter meets a client's 20,000 kWh annual goal. Site data for the location gives 1,700 kWh of yearly energy per installed kilowatt, and the loss budget for temperature, wiring, soiling, and conversion totals 25%. Which annual production estimate best supports the go or no-go decision?
- An engineer reviews a coastal ground-mount where heavy panels sit still but winter gusts shake racks and crews walk rows for cleaning. Which load distinction should the associate state to separate structural considerations for static from dynamic loads?
- A school wants a 40 kW array but the main roof is shaded, old, and weight-limited while the parking lot needs shade and the field has open sun with trenching room. The board wants low roof risk, driver comfort, and easy mowing access. Which mount comparison among ground, roof, and canopy options best fits these site goals and constraints?
- A 1,600 sq ft home uses about 9,000 kWh per year with steady daytime loads, good south roof space for 9 kW, and the utility limits residential net-metered systems to 7.6 kW AC output with a 40A backfeed breaker. The designer estimates a 7 kW DC array makes about 10,000 kWh yearly with a 7.6 kW inverter. Which array size best balances load coverage with interconnection limits?
- A 12-kW home addition needs plan approval in a jurisdiction that adopts the NEC with state amendments, plus local zoning setbacks and fire access pathways. The designer cites national listing, state electrical rules, and city roof access rules. Which code responsibility assignment should the designer use to show electrical, building and fire code roles?
- A community center wants 40 kW and shade for its lot. Its flat roof is at its load limit and needs new membrane in five years, and its side field is protected wetland that cannot be graded or trenched. The lot gets full sun and the owner will pay more steel cost for dual use. Which mount choice best fits these structural and site limits?
- You survey a 1970s ranch for a 6-kW flush-mount retrofit. The attic shows 2x8 site-cut rafters on 24-inch centers with collar ties, and the roof has three-tab asphalt shingles over one layer with exposed nail heads. Which roofing and framing identification should the designer record to guide the mounting plan?
- You design a 12-kW home system where the city permit desk cites NEC for wiring, IBC for roof loading, and IFC with local setback amendments for fire access. The state adopts NEC with amendments and the AHJ has final say. Which allocation correctly distinguishes electrical, building, and fire code roles?
- A small shop uses about 900 kWh per month with steady daytime fridges, and the roof fits 12 kW DC but the utility letter caps this site at 8 kW AC output. The owner wants the largest allowed bill cut without a service upgrade. Which PV system sizing choice best aligns array output against load analysis and interconnection limits?
- A designer is stringing a 16-module warehouse rooftop array in a hot climate. Each module has a 9.6 A maximum-power current, reaches 43.0 V open-circuit at the coldest design temperature, and falls to 31.0 V at maximum power on a hot roof. The inverter has four MPPT inputs, each with a 15 A maximum operating-current limit and a 600 V maximum voltage, and tracks down to a 160 V floor; all sixteen modules must be installed. Which string layout keeps every module inside the inverter's voltage and current windows at both temperature extremes?
- A designer surveys a 1970s ranch with dimensional shingles over widely spaced sawn rafters and a small addition with engineered trusses plus a flat garage with black membrane. She must choose attachments and spans without overloading frames. Which roofing and framing assessment best guides the plan?
- A designer has twelve 410W modules with 45V open-circuit each, a 30F record low, and a string inverter rated 600V max with a 200-500V MPPT window and 15A input limit. Module voltage rises in cold and the 10A short-circuit current fits well. Which string plan stays within inverter limits across seasons?
- A designer reviews two datasheets for a string calculation on a cold-climate home: Module A lists 41 V open-circuit voltage and 11 A short-circuit current at STC, plus temperature coefficients. Which reading correctly uses STC, open-circuit voltage, and short-circuit current for this design?
- A new hire is confused when the foreman cites OSHA for fall protection, ANSI for harness testing, and NFPA 70E for arc-flash practice on the same commercial rooftop job. The manager wants clear roles. Which workplace safety standard distinction should the trainer use to identify OSHA, ANSI, and NFPA responsibilities?
- You lay out a 100-kW flat-roof design requiring fall protection, safe ladder use, and arc-flash labeling with crew training records. The owner asks which workplace safety standards govern each duty versus electrical installation rules. Which reference correctly identifies OSHA, ANSI, and NFPA workplace safety roles?
Installation (18.3%) · 55 questions
- A crew must add 40 kW on a two-story office with a flat membrane roof that forbids penetrations, keeps a 10-year warranty, and needs wind-rated hold-down. The owner wants no grading or foundations. Which mounting type matches this flat-roof constraint?
- A two-person crew is pulling PV source conductors into EMT on a hot commercial roof with several 90-degree bends, plus a short flexible whip into an inverter with vibration. The foreman wants neat, code-typical protection at entries and joints. Which fitting selection best meets strain relief and bushing needs for this run?
- A crew is building a ground-mount rack on a sloped, rocky lot. The six posts are already set in concrete, and the rails must sit in one level plane before the modules go on. Which tool set lets them fasten the pressure-treated ledgers and true up the rail plane in one pass?
- On a residential re-roof, half-inch plywood sheathing is nailed over 2x8 SPF rafters spaced 16 inches apart. The mount plan requires 1-1/2 inches of bite into each rafter, a 3/8-inch shank, stainless hardware to match the aluminum rail assembly, and a pilot hole to prevent splitting. Which fastener should the installer drive at each mount to satisfy all four requirements?
- You arrive to commission a 10-kW home system with a new inverter, monitoring gateway, AC disconnect, and labeled rapid shutdown switch. The array tests clear and the roof work is done. Which commissioning sequence verifies inverter operation, communications, and disconnects before handoff?
- A garage retrofit adds a wall-mounted lithium battery, a hybrid inverter, and a critical-loads panel fed during outages. The crew has arc-flash, disconnect, and NEC-required placards ready. Which storage labeling and marking approach completes the install for first responders?
- A coastal installer is labeling a rooftop DC disconnect and inverter area exposed to sun, rain, and salt spray, and the AHJ will re-inspect in five years. The crew wants labels that stay legible for the system life. Which labeling approach best meets durability for PV markings?
- A 12-kW system passed local inspection yesterday and the monitoring portal shows steady production, but the owner asks to flip the main solar breaker on today. Interconnection approval is still pending with the utility. Which commissioning document and permission-to-operate step allows legal energizing?
- A crew is installing a listed rail system that uses piercing clips under modules to bond frames to rails, with one lug tying the rail to the EGC. Wind, dust, and rushed torque guns threaten the connection. Which installation practice correctly applies listed bonding components for integrated grounding of this array?
- An installer is mounting an AC disconnect for a residential array. The manual lists the enclosure as NEMA 1 and gives a torque value for each terminal, but the crew plans to hang it on the exterior wall beside the meter where rain runs down the siding. An indoor spot in the attached garage stays within reach of the equipment. Which mounting and tightening decision meets both requirements?
- A ground-mount crew has stamped site plans calling for 8-foot post spacing, shared rails, and a torque table, but the foreman suggests wider spacing to save piles on rocky soil. The permit set is already approved. Which action follows manuals and site-engineered plans correctly?
- Commissioning a 60-kW rooftop array, you find string tags at the combiner box that do not match the tags on the module rows, and no crew member can confirm which set is right. The as-built drawing predates two late field changes, and owner sign-off is tomorrow morning. Which verification step should you run first to reconcile the string labeling?
- You commission a 9-kW home system with battery backup and app monitoring for owners new to solar. They need daily use habits, what the portal means, and what to do in a fire or outage. Which owner orientation best covers operation, monitoring, and emergency response?
- Commissioning of a 16-kW ground-mount array on a clear morning shows five inverter inputs reading about 420 V, one input reading 0 V, and a thermal scan showing one combiner connector 35 °C hotter than its neighbours. The associate wants to clear both findings in a single pass. Which measurement should come first to locate the dead string?
- An installer is mounting a wall inverter with an adjacent AC disconnect in a commercial electrical room where boxes and mops are stored against the gear and the door swings toward the worker. Which working-clearance practice best preserves safe access to this electrical equipment?
- A 12 kW array is planned for the roof of a community center covered three years ago with a 60-mil TPO membrane at 2/12 pitch. The remaining single-ply warranty requires that every penetration be made and sealed by a factory-authorized applicator, and the structural review finds insufficient capacity for a ballasted system. Which mounting attachment plan keeps the roof warranty in force once the array runs?
- You are wiring a 12-kW rooftop string inverter job in Tampa with long conduit runs along a parapet and up to modules. The plan notes wind movement, rain pooling, and sharp enclosure knockouts. Which wiring method best follows best practice for drip loops, bend radius, support, and protection from damage?
- Your crew is setting aluminum rails on a shingle roof for a 9-kW home, driving lags into rafters, and torquing rail bolts to spec. The kit lists an impact driver, socket set, torque wrench, and chalk line, plus a grinder with a cutoff wheel. Which tool selection fits this mounting-structure task correctly?
- An installer is running EMT along a hot attic into a rooftop junction box and must transition to a short flexible whip to the inverter while keeping conductors protected where they enter enclosures. Which fitting choice best completes this electrical equipment installation?
- You plan three small builds: a sealed membrane flat roof that cannot be pierced, a shingle pitched roof with attic rafters, and an open field with expansive clay. Which mounting type match best fits flat roof, pitched roof, and ground mount needs?
- You are landing aluminum feeders in a 200-A rooftop AC disconnect that lists a torque value, a wire range, and a NEMA 3R enclosure mark. The site sees wind-driven rain and the inspector will check lugs and cover seating. Which termination and enclosure practice meets manufacturer and rating needs?
- At final checkout of a 15-kW residential hybrid system with battery, the homeowner reports the app shows no data and the system stayed on during a required rapid-shutdown test. Which verification of inverter operation, communications, and disconnects should the associate perform?
- On a 12-kW rooftop retrofit the crew must land stranded aluminum feeder conductors in a combiner with lugs marked CU-ONLY, the site is coastal and damp, and the foreman wants a durable low-resistance joint. Which conductor and termination compatibility rule should the installer apply to make this connection safe?
- You are laying out flush-mount rails on a comp-shingle home with 24-in. on-center trusses, per the rail maker table that limits support spacing and rail overhang past the last mount. You find truss lines with a stud finder and attic check, then mark two rail lines. Which layout check should you verify to confirm span and cantilever compliance?
- A 30-kW rooftop system for a hardware store passed the AHJ inspection on Tuesday, and the owner wants it running for a Friday event. The utility's interconnection review is still open, the revenue meter swap is booked for next week, and the monitoring portal account still needs registering. Which action satisfies the permission-to-operate requirement today?
- An installer is labeling a rooftop DC disconnect, an outdoor inverter, and an AC panel fed by a new 6 kW system in a sunny, rainy climate. The labels must remain legible for the life of the system. Which labeling practice meets marking durability requirements?
- You are mounting aluminum rails to pressure-treated wood blocking on a coastal home with stainless rail hardware and a galvanized flashing kit, within sight of salt spray. Which fastener choice should you specify to meet strength, size, and metal compatibility?
- A two-person crew is setting rail-based flush mount on tile hooks where the site plan lists specific spans, lag size, and torque values tied to the engineering stamp. The lead wants to speed up by widening spans and guessing torque. Which mounting practice follows manufacturer manuals and site-engineered plans?
- You are placing a wall-mounted inverter and AC disconnect in a 10-kW garage installation where the owner wants storage shelves beside the gear and the concrete wall allows flexible layout with no windows or sinks nearby. Which placement maintains proper working clearances for electrical equipment installation?
- An off-grid cabin owner must choose batteries for a small solar shed that is unheated in winter, visited monthly, and needs low upkeep with safe indoor placement. Which lithium versus lead-acid comparison should guide this energy storage choice?
- After a 10-kW battery-ready install, the owners are unsure how to read the app, when to call service, and how to shut down safely in a storm or fire. The lead has 20 minutes for handoff. Which owner orientation on operation, monitoring and emergency response fits best?
- On a rail-mounted home array, the plan calls the aluminum rails the equipment grounding path using WEEB-style clips between modules and rails plus a single lug to the grounding conductor. Which check should the installer perform to apply integrated grounding and listed bonding components?
- You are wiring a 13-kW rooftop-to-attic run where metal conduit passes through a sharp panel enclosure knockout, joins to a second conduit length outdoors, and enters a junction box that needs a watertight cable pass for the monitoring line in a rainy climate. Which choice of fittings with connectors, couplings, bushings, and strain reliefs best protects the conductors?
- A two-person crew installs a wall-mounted lithium battery with a hybrid inverter in a garage, the manual requires a specific startup order, torque values, and closed-loop communication settings, and the lead wants to finish before the inspection window closes. Which practice for following manufacturer programming and safety instructions best ensures a safe startup?
- You are wiring a 12-kW home roof array where DC homeruns drop down an exterior wall to a garage inverter, exposed to sun, rain, and lawn tools. The foreman wants neat work that will pass inspection and last. Which wiring best practice for drip loops, bend radius, support, and damage protection should the installer use?
- A designer sizes a 12-kW array for a house with a 10:12 clay tile roof, but the homeowner will not allow any penetrations through the 26-year-old tile. There is no attic access for rafter layout, the driveway is too narrow for a carport, and a level side yard large enough for the array sits unshaded beside the meter. Which mounting structure type matches these site facts best?
- A crew plans a 36-module array on a 10-year-old standing-seam metal shop roof pitched at 4/12. The panel maker's 30-year warranty is voided by any pierced fastener and no solar waiver exists, the panels carry a limited point-load rating between purlins, the roofer's spec caps ballasted roof mounts at 2/12, and the site has no yard space. Which mounting system satisfies the warranty, load, slope, and site limits?
- A crew adds a second battery cabinet to a basement system with PV disconnects, a battery disconnect, and an exterior rapid-shutdown switch, the inspector flagged missing directional cues last time, and the owner needs clear emergency actions. Which storage labeling and marking approach best meets field expectations?
- A crew is finishing a garage string inverter and rooftop disconnect on a coastal home with sun, rain, and salt spray. The foreman rejects handwritten tape flags and plain indoor stickers for field labels. The owner wants labels legible for years. Which labeling and marking approach meets durability requirements for PV field equipment?
- A designer lays out rails on a home with 24-inch truss spacing, 5/8-inch plywood deck, and a hip roof needing rails across three supports with short overhang. Which structural locating and span judgment should the installer use to set safe attachments?
- An install lead is setting aluminum rail on shingle mounts for a 7-kW crew build with L-feet, lag screws, and torque-marked rail bolts, working on a hot roof with limited time. The foreman wants fast but spec-ready rails. Which common power and hand tool practice should the crew use for the mounting structures?
- You terminate #10 copper PV wire into an inverter lug marked AL7CU, 75C, with torque specs, in a hot garage where a prior job mixed metals and overheated. The apprentice asks if any lug and wire will do. Which conductor and termination compatibility check should the installer make for safe current flow?
- A grocery store pairs its rooftop PV with storage to shave demand peaks. The bank will cycle daily to about 40% depth of discharge, sit in a battery room reaching 40 °C in summer, and get service only once a quarter, with a ten-year life target. Which battery type best fits that duty cycle?
- An installer on a permitted home array finds the racking manual torque differs from the site-engineered plan stamp, with mismatched clamp part numbers and a revised rail spacing note. Which practice correctly follows manufacturer manuals and site-engineered plans before proceeding?
- A crew just finished a 6-kW home roof install with two strings, rail mounts, and a string inverter in the garage. The foreman wants a final QA walk before startup to catch loose hardware, wire damage, and labeling gaps. Which visual inspection and QA/QC checklist control should the crew complete to confirm install quality?
- A trainee is landing aluminum service conductors in a new outdoor inverter cabinet rated for wet locations, with a torque table inside the door. The foreman stresses loose lugs cause heat and water entry voids the rating. Which termination practice should the trainee apply to meet manufacturer torque and NEMA enclosure requirements?
- You are routing DC conductors down an exterior stucco wall to an inverter on a home with afternoon sun and weed trimmers nearby. The run sags between clips and enters the box from the top without slack. Which wiring best practice should the crew apply to protect this exposed run?
- A crew mounts aluminum rails on a home 500 feet from salt water using stainless L-feet and lag screws into rafters with flashing. Morning dew keeps joints damp for hours and past jobs show white crust and pitting where bare steel touched aluminum. Which fastener practice best ensures strength and metal compatibility?
- An installer is asked to mount flush rails on a 6-year-old architectural shingle roof at 4:12 pitch with one soft spot near a valley, and the owner provides a 25-year shingle warranty that bars non-approved sealants and grinding. The attic shows 24-inch truss spacing. Which mounting assessment best respects roof type, pitch and warranty impact?
- An installer is placing a wall-mounted inverter and AC disconnect in a cramped garage with boxes stacked in front, a workbench beside the panel, and low headroom. The inspector cites access and escape space. Which working clearance practice should the crew apply for electrical equipment installation?
- You commission a 10-kWh wall battery paired with a hybrid inverter in a garage with limited ventilation, where the manual specifies torque, firmware, charge limits, and PPE for arc and chemical hazards. Inspection requires listed settings and labeled disconnects. Which commissioning approach follows manufacturer programming and safety instructions?
- A helper staged aluminum USE-2 for a rooftop DC run, copper-only lugs in a combiner, and no anti-oxidant or torque tools for a hot coastal site. Which judgment about conductor and termination compatibility should the lead enforce before landing wires?
- During commissioning of a 10-kW roof with three strings, the inverter shows low power and one MPPT reads near zero volts in full sun. The lead suspects a dead string, crossed leads, or a hot joint in the combiner. Which commissioning test of string voltage, polarity and thermography best isolates the fault?
- A crew installs a listed rail system with integrated grounding clips that pierce anodizing to bond modules to rails, plus a copper lug for the equipment ground wire. The inspector wants continuous fault path with no field improvising. Which grounding method best uses listed bonding components?
- A crew must set flush-mount rails on a home with 24-inch on-center trusses, 7/16-inch OSB decking, and a layout needing a 6-foot rail span with 2-foot end overhang past the last mount. The lead suspects a weak bay and wide cantilever. Which structural check best judges span and cantilever for rafters, trusses and decking?
Operations and Maintenance (13.3%) · 40 questions
- A small business wants to sell solar credits that pay by the kilowatt-hour and the utility requires audited production data with tight error limits. The crew installed a standard inverter display and a consumption CT set. Which monitoring choice describes revenue-grade metering for credit payments?
- A homeowner calls three months after install because a 6-kW rooftop system shows 12% lower monthly energy, with pollen season, nearby tree growth, pigeon nesting under edge modules, and no breaker trips reported. Which loss explanation best accounts for this deviation from expected performance?
- During O&M on a 12-module string reading low power at midday, the inverter display reports only 380 V on the string while the tech expects about 480 V open-circuit, with intact wiring and no shade. The lead asks for a safe first electrical check. Which multimeter task isolates the voltage fault correctly?
- During commissioning of a 12-module string, you capture an IV curve on a sunny day to verify health before handoff. The curve shows zero-current voltage, zero-voltage current, and a knee where power peaks. Which IV curve reading correctly identifies Isc, Voc, and maximum power point for this string?
- During commissioning of a 12 kW rooftop array, a tech uses a handheld tracer on one string at midday and records open-circuit, short-circuit, and peak-power values to compare with the datasheet. The crew leader asks for a clear field reading of curve points. Which reading best identifies Isc, Voc, and maximum power point?
- A maintenance tech must check an older 600-V string for degraded insulation after a ground fault cleared. The array can be isolated, the sun is up, and the crew has lockout gear. Which use of an insulation tester (megohmmeter) yields a valid reading safely?
- A 120-kW rooftop system for a grocery store shows healthy irradiance and no faults, yet output flatlines at 50 kW on sunny afternoons per the utility interconnection agreement that caps export to protect the feeder. Which curtailment and export-limitation behavior best explains this deviation from expected performance?
- An O&M tech is chasing repeated ground-fault alarms on a 3-year-old rooftop string that reads low isolation resistance at the inverter. The array is de-energized, LOTO applied, and conductors are isolated for testing in dry daylight. Which insulation tester practice gives a valid leakage check that shows which conductor is leaking?
- You maintain a 12-kW rooftop array with central monitoring. On a clear day the site pyranometer drops from 1000 to 400 W/m2 when thin clouds pass, cell temperature stays near 25C, and the inverter stays online with no faults. Output current falls sharply while DC voltage dips only slightly. Which performance statement best explains this irradiance effect?
- You maintain two identical 10-kW rooftop systems in Phoenix. At 9 a.m. under light haze both show 610 Vdc and 6 A, and at solar noon under clear sky both show 625 Vdc and 14 A. Your supervisor asks for a status note. Which statement correctly explains irradiance effects on performance parameters?
- You maintain a 250-kW rooftop with bifacial modules where output dropped 8% on clear windy days. The pyranometer looks dusty and tilted, no rear-irradiance data exists, and wind logs are missing. Which weather sensor action best diagnoses irradiance, bifacial gain, and cooling effects?
- A 40-kW commercial rooftop array underperforms on clear days after visual inspection shows no major soiling or shade. The O&M lead assigns IV curve tracing on suspect strings. Which IV curve tracer practice should the technician use to isolate the electrical fault?
- A tech supports a 48 V lead-acid battery bank at a remote irrigation site. The controller has used one fixed absorb voltage since commissioning, the cabinet swings from near freezing at dawn to hot by afternoon, and the pump runs all night while the array starts before anyone arrives. The operator wants to know how much pumping time is left. Which two monitoring inputs should he fit?
- An O&M tech inherits a 60-kW rooftop system with nuisance trips, faded wire labels, and no history after the original installer closed, and the owner wants reliable troubleshooting going forward. Which record-keeping practice best supports safe maintenance of this PV system?
- You service a 9-kW home system in Charlotte with a string inverter listed 200-500 Vdc MPPT range and 600 Vdc max, plus 240 Vac output. On a cold morning it shows 545 Vdc at low power and frequent restarts. Which interpretation of inverter AC/DC voltage and MPPT range best explains the fault?
- During a noon maintenance visit on a 25-kW rooftop array with one warm combiner fuse and normal inverter output, the tech carries an IR thermometer and a thermal camera. Which diagnostic use of the IR thermometer and thermal camera should the tech choose to locate the heat fault safely?
- A maintenance lead suspects soiling plus one weak bypass diode in a 12-module string after a hot dusty month. Open-circuit voltage looks near normal, but midday power sags and infrared shows one hot module. Which IV curve tracer use best isolates the fault?
- You are checking a 6-kW residential string inverter at midday that lists 230-V AC output and a 200-480-V MPPT range, and the monitoring portal shows 180-V DC input with low power during full sun and no shade or faults logged. Which interpretation of inverter AC/DC voltage and MPPT range best explains the reduced performance?
- During a midday O&M visit for a 12-kW rooftop string with low output, you suspect a hot fuse holder and one warmer module section. Ambient is 28C, wind is calm, and the array is under steady sun. Which instrument practice should you use to screen with the IR thermometer and thermal camera?
- During commissioning of a 10-kW hybrid system with backup, the grid sags on a hot afternoon, frequency wavers, and the battery bank reads low after overnight loads. Which relationship among utility voltage and frequency and battery voltage and state of charge should the technician use to explain operation?
- During O&M training, techs compare a 400-W nameplate to lower midday field output on a warm roof with light wind. The data sheet lists both STC and NOCT ratings. Which comparison of STC and NOCT test conditions best sets expected performance?
- A technician visits a 5-year-old 12 kW rooftop array after a hailstorm and high winds for a scheduled O&M check with no monitoring alerts. Production looks normal on the app. Which visual inspection routine best fulfills maintenance of PV systems?
- A six-month-old 8-kW rooftop string system shows one string 18% low at solar noon with no inverter fault, clean sky, and matching tilt. Thermal scan shows one hot bypass area and a shaded lower corner from a new vent pipe. Which installation deficiency diagnosis is correct?
- A maintenance tech must verify a suspected soiling loss on a 50-kW roof array at solar noon on a clear day, comparing meter readings to expected output and the monitoring portal. Which irradiance meter practice yields a trustworthy check?
- A two-person O&M crew is checking a 12-kW roof array that reads low at midday with no tripped breakers, clean sky, and a south tilt of 28 degrees. The lead asks for a plane-of-array sun check to compare output to expected watts. Which irradiance meter technique should the crew use to verify expected array output?
- You are the O&M tech at a 200-kW rooftop site where an inverter cooling fan has seized after six years, and the spare kit is on site. The disconnects for AC and DC are locked only by you, and the site log requires service dates for wear parts. Which lockout/tagout and service-life replacement procedure should the technician follow for the fan assembly?
- A homeowner with a 7 kW rooftop system reports low credits for two weeks, the installer sees normal status on the fleet web portal, and the homeowner wants daily checks without a site visit. The inverter display on-site shows no fault code. Which monitoring method best fits ongoing homeowner daily checks and remote troubleshooting support?
- A home has a battery-based inverter tied to the grid with backup loads. During a storm the lights flicker, the inverter disconnects from the grid and powers backup loads, then it shuts down overnight even though solar is idle. Morning checks show grid sag with unstable frequency and very low battery voltage. Which operating relationship among utility voltage and frequency and battery voltage and state of charge explains the shutdown?
- During maintenance on a flooded lead-acid off-grid bank, one string shows low voltage under load, full electrolyte levels, and clean terminals after an equalize charge. Which electrical test equipment choice correctly uses a load tester, hydrometer, and refractometer to diagnose battery condition?
- An O&M tech is servicing a small off-grid cabin with four flooded lead-acid batteries showing uneven run time, low specific gravity alarms, and sulfation risk after a cold week. The owner wants cell-level health before equalizing. Which battery test sequence should the tech use with load tester, hydrometer, and refractometer?
- A technician at a 750 kW carport array is told the SCADA power trend has been flat since 06:12, while every inverter's front panel shows normal output and no alarms. The site collects field data through a data logger that polls the inverters and meter before sending values to the SCADA host. Which data acquisition check should the technician run first to locate the break in the monitoring path?
- During O&M on a 50-kW roof system the dashboard shows low output, the crew hears buzzing at a combiner, and smells hot plastic near cracked conduit. Which fault recognition should the tech apply to distinguish arc faults from ground faults?
- An O&M tech supports 30 homes with app access plus a fleet web portal and local inverter screens. One owner reports low credits but shows only a green light, the office needs fleet faults, and the site has no phone signal for remote checks. Which monitoring method comparison among app, web, and on-site best directs each troubleshooting need?
- You service a 25-kW dusty rooftop array at noon in Arizona with warm modules, visible soiling, and prior hot connections. The manual lists connector torque values and allows only soft cleaning with low-mineral water. Which torque and cleaning practice best protects performance and connection safety?
- An O&M tech inherits a 250-kW rooftop portfolio where inverters log locally but owners get no alerts, and a new SCADA scope is proposed. Which description correctly states what data acquisition and SCADA should provide for this fleet?
- A 10 kW rooftop system in Texas shows lower midday power on a 104F calm afternoon than on a breezy 85F morning, though sunlight looks equally bright and no clouds or soiling are found. The owner asks why heat and wind matter. Which explanation best describes temperature and wind effects on output?
- At a 30-kW shop the portal shows solar output far below the inverter screen, and the tech finds small doughnut sensors around the feeders plus small boxes tied to voltage leads in the monitor panel. Which monitoring equipment explanation correctly describes current and potential transformers?
- A 50-kW rooftop array in a desert town shows lower midday summer power than its nameplate suggests, but output rebounds on cool windy afternoons despite identical sunlight. The owner suspects soiling only. Which temperature and wind effect explanation should the technician give for performance parameters?
- A crew lead asks how a multimeter can check continuity of the equipment bonding path from a module frame to the designated equipment grounding point. Which demonstration best checks that path’s continuity?
- A high-desert 10-kW array with white gravel logs midday power 8% above model on a cold, clear, windy day with puffy clouds, even though the sun angle is low. The tech sees brief spikes as clouds pass and snow glare from nearby drifts. Which factor set best explains these production gains?
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