CSLB C-46 Solar (Trade Exam) — All Questions
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42 questions
An array covers 28 percent of a home's plan-view roof area, and the home has no sprinklers. What setback is required at a horizontal ridge?
- a.18 inches on both sides✓
- b.No setback below 33 percent
- c.36 inches on both sides
- d.18 inches on one side only
For arrays covering not more than 33 percent of the plan-view roof area, the 2022 CRC requires at least 18 inches of clear setback on both sides of a horizontal ridge. The setback is reduced, not removed, below 33 percent.2022 CRC R324.6.2 (City of Berkeley checklist)
A sprinklered home (NFPA 13D) will have an array covering 70 percent of its plan-view roof area. What ridge setback applies?
- a.36 inches on both sides✓
- b.12 inches on both sides
- c.18 inches on both sides
- d.None, because it is sprinklered
With an automatic sprinkler system, the alternative setback is 18 inches for arrays covering up to 66 percent of plan-view roof area and 36 inches above that. At 70 percent, 36 inches applies.2022 CRC R324.6.2.1 (City of Poway list)
Which roof is exempt from the residential PV pathway requirements?
- a.A 9:12 roof on a detached garage used as a studio
- b.A 1.5:12 low-slope roof on a house✓
- c.A 4:12 roof on a two-story house
- d.A 6:12 roof with a small array
The pathway rules do not apply to roofs with slopes of 2:12 or less, or to non-habitable structures. A studio is habitable, and steeper roofs on houses are covered regardless of array size.2022 CRC R324.6 (City of Poway list)
Under which standard must a rooftop-mounted PV panel system be tested and listed for its fire classification?
- a.UL 2703✓
- b.UL 1973
- c.UL 9540
- d.UL 1741
The 2022 CRC requires rooftop-mounted PV panel systems installed on or above the roof covering to be tested, listed and identified with a fire classification in accordance with UL 2703. UL 1741 covers inverters and UL 9540 covers energy storage systems.2022 CRC R902.4 (County of Lake excerpt)
What added dead load does NREL say a typical attached (not ballasted) rooftop PV system adds?
- a.About 15 pounds per square foot
- b.About 25 pounds per square foot
- c.Less than 3 pounds per square foot✓
- d.3 to 8 pounds per square foot
NREL reports that an attached system adds less than 3 pounds per square foot of collector area, while a ballasted system adds 3 to 8 pounds per square foot depending on tilt and wind loading.NREL Best Practices for O&M of PV and ESS
Why does NREL prefer through-bolting to clamps for PV rack hardware?
- a.Through-bolts eliminate the need for flashing
- b.Clamps can release in a storm✓
- c.Through-bolts need no corrosion protection
- d.Clamps are not allowed by any code
NREL notes clamps may have the specified strength in the proper orientation, but relative movement, rotation or vibration of rack parts in a storm can cause them to release; through-bolting is preferred. Flashing is still required.NREL Best Practices for O&M of PV and ESS
What must be true of every roof penetration made for a PV installation, per San Diego County's checklist?
- a.It must be inspected by the roofer
- b.It must be at least 24 inches from a rafter
- c.It must be secure and weather-tight✓
- d.It must be sealed with silicone only
San Diego County's checklist requires all roof penetrations to be secure and weather-tight. The method follows the approved plan and manufacturer details, not a single sealant type.County of San Diego PDS 081S (2025 codes)
What does a single-axis tracker on a ground-mounted array typically do?
- a.Points directly at the sun all day in both axes
- b.Tilts the array toward north in winter
- c.Rotates the array only at night
- d.Follows the sun from east to west✓
DOE explains that one-axis trackers typically track the sun from east to west, while two-axis trackers keep modules pointed directly at the sun throughout the day. Trackers add cost and maintenance.DOE, Solar Photovoltaic System Design Basics
Which standard lists photovoltaic shingles used as the roof covering?
- a.UL 9540
- b.UL 1741
- c.UL 2703
- d.UL 7103✓
The 2022 CRC requires PV shingles to be listed and labeled in accordance with UL 7103 and limits them to roof slopes of 2:12 or greater. UL 2703 applies to rack-mounted PV systems.2022 CRC R905.16 (County of Lake excerpt)
At inspection, which statement about exposed array conductors must be true?
- a.They may rest loose on the roof surface
- b.They must run through the attic in PVC
- c.They are secured, supported and protected✓
- d.They must be painted to match the roof
The Guidebook's inspection list requires array exposed conductors to be properly secured, supported and routed to prevent physical damage. DC circuits inside a building must be in metal raceway, MC cable or metal enclosures, not PVC.Solar Permitting Guidebook (OPR) inspection checklist
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What does NREL say a ballasted rooftop rack requires beyond the general ASCE 7 requirements?
- a.Advanced wind-loading evaluations✓
- b.A ground-mounted backup array
- c.A fire classification of Class C only
- d.No wind review, since ballast holds it down
NREL states that to use a ballasted rack, advanced wind-loading evaluations have to be performed above the general requirements of ASCE 7, and wind loading usually decides whether ballast is feasible.NREL Best Practices for O&M of PV and ESS
Which fastener does NREL describe as more likely to pull out of PV racking over time?
- a.Stainless steel bolts
- b.Listed lag screws into rafters
- c.Self-tapping screws✓
- d.Through-bolts with nuts
NREL notes that self-tapping screws are more likely to pull out and weaken over time from corrosion, and that through-bolting is preferred to clamps in rack hardware.NREL Best Practices for O&M of PV and ESS
According to NREL, roofing contractors frequently guarantee their workmanship for how long?
- a.30 to 40 years
- b.Exactly 1 year
- c.Only until the first rain
- d.Between 5 and 10 years✓
NREL notes that roofing contractors often guarantee their work for between 5 and 10 years for workmanship, which a PV installation can affect if penetrations are not made to the roofing and racking details.NREL Best Practices for O&M of PV and ESS
How often does NREL's sample service schedule call for inspecting roof penetrations for degrading sealant?
- a.Only when a leak is reported
- b.Never, once flashed
- c.Once a year✓
- d.Once every 10 years
NREL's sample service schedule includes inspecting roof penetrations once a year to ensure sealant is applied properly and not degrading.NREL Best Practices for O&M of PV and ESS
A building-integrated PV system hides electrical hazards from view. What does the 2022 California Fire Code require?
- a.No markings, since BIPV is part of the roof
- b.Reflective markings of the hazard areas, visible from grade✓
- c.A fence around the building
- d.Removal of the BIPV at night
The 2022 CFC requires markings identifying hazardous areas to avoid where BIPV creates hidden electrical hazards, and the markings must be reflective and visible from grade.County of Lake 2022-code excerpt (CFC 1205.2.3)
Which smoke ventilation option between array sections does the 2022 California Fire Code allow on larger buildings?
- a.No pathway if modules are Class A
- b.A pathway not less than 18 inches wide
- c.A pathway not less than 8 feet wide✓
- d.A single roof hatch anywhere on the roof
The 2022 CFC's smoke ventilation options between array sections include a pathway at least 8 feet wide, or a 4-foot pathway bordering 4-by-8-foot venting cutouts every 20 feet on alternating sides.County of Lake 2022-code excerpt (CFC 1205.3.3)
Why does NREL say ground-mounted arrays usually need more cleaning than rooftop arrays?
- a.They face north
- b.They sit closer to dust and pollen✓
- c.They are cleaned only by rain
- d.They have no glass
NREL notes that cleaning requirements increase for ground-mounted arrays because they are closer to the source of airborne dirt and pollen.NREL Best Practices for O&M of PV and ESS
At least one fire access pathway on a residential roof must be located where?
- a.On the street or driveway side✓
- b.On the side facing the neighbor
- c.On the plane with the most modules
- d.On the rear roof plane away from view
The rule calls for at least one pathway on the street or driveway side of the roof. The neighbor's side is not the stated location. A rear-only layout would leave the street side without a pathway. The plane with the most modules is not what the rule uses.2022 CRC R324.6 (City of Berkeley checklist)
How must a rooftop-mounted PV panel system be installed under 2022 CRC R907?
- a.Only per the manufacturer's instructions✓
- b.To whatever layout the neighbor's roof has
- c.As the roofer prefers on the day of the job
- d.By the method that costs least
R907 says PV panel systems mounted on top of a roof are listed and labeled to UL 2703 and installed in accordance with the manufacturer's installation instructions. The installer's or roofer's preference does not replace the listing's instructions. Another house's layout has no bearing on this roof. Cost is not a basis for departing from the listing.2022 CRC R907 (County of Lake excerpt)
Which documents does San Diego County's checklist want available on site at the PV inspection?
- a.The utility interconnection agreement signed by the buyer
- b.Manufacturer cut sheets and installation manuals✓
- c.The customer's electric bills
- d.The crew's ladder inspection logs
The checklist asks that manufacturer cut sheets and installation manuals be available at inspection so the inspector can check the work against them. Electric bills do not show how the system is installed. The interconnection agreement is a utility document, not an installation reference. Ladder logs do not describe the PV installation.County of San Diego PDS 081S (2025 codes)
Sandia says PV conductors under modules close to a structure, on still, hot days, can reach about what temperature?
- a.35 to 40 degrees C
- b.95 to 105 degrees C
- c.65 to 75 degrees C✓
- d.45 to 50 degrees C
Sandia reports conductor temperatures as high as 65 to 75 degrees C in those conditions, which is why temperature correction matters. 35 to 40 degrees C is ordinary warm air. 45 to 50 degrees C understates the heat trapped under modules. 95 to 105 degrees C is above Sandia's stated range.Sandia, PV Power Systems and the NEC: Suggested Practices
On what area are the ridge setback coverage percentages calculated?
- a.The footprint of the racking rails
- b.The sloped surface area of the roof
- c.The plan-view roof area✓
- d.The area of the whole lot, sloped or not
The percentage thresholds use the plan-view total roof area, the roof as seen from above. Sloped area is larger and gives a different percentage. The racking footprint is not the roof area. Lot area has no connection to roof coverage.2022 CRC R324.6.2 (City of Berkeley checklist)
An attached array of 20 modules, each 21 square feet, adds about 2.8 pounds per square foot of collector area. What is the added dead load?
- a.About 56 pounds
- b.About 11,760 pounds
- c.About 420 pounds
- d.About 1,176 pounds✓
Total area is 20 x 21 = 420 square feet, and 420 x 2.8 is about 1,176 pounds. 56 pounds multiplies the module count by the load per square foot and skips the area. 420 pounds is the area itself, not the load. 11,760 pounds moves the decimal one place too far.NREL Best Practices for O&M of PV and ESS
An array integrated with the roofing material must be rated how under San Diego County's checklist?
- a.Unrated for arrays under 10 kW
- b.Class B, per the UL 1741 listing
- c.Class A, per ASTM E 108 or UL 790✓
- d.Class C, the rating for residential roofs
The checklist requires arrays integrated with roofing material to be Class A rated per ASTM E 108 or UL 790. Class C is a lower rating than the checklist calls for. Size does not exempt an integrated array from the rating. UL 1741 is an inverter standard, not a roofing fire rating.County of San Diego PDS 081S (2025 codes)
Which rafter framing standard does Berkeley accept for a flush-mounted residential array without a project-specific engineered design?
- a.Conventional framing, CRC R802.5✓
- b.The deck-framing tables for a patio cover
- c.A neighbor's recently permitted roof plan
- d.None; an engineered design is required
Berkeley accepts rafters that meet the conventional framing standards of CRC R802.5 for ordinary flush-mounted residential arrays. Deck framing tables are for a different structure. A neighbor's plan has no bearing on this roof. Engineering is triggered by tilt-up racks and other special cases, not every roof.City of Berkeley 2022-code checklist
Where does San Diego County's checklist say roof access points for firefighters should be placed, apart from avoiding ladder placement over doors and windows?
- a.Directly over the front door of the house
- b.At strong points, clear of obstructions✓
- c.At the weakest corner so the roof opens easily
- d.Beneath the lowest row of modules on the roof
Access points go at strong points of building construction where they do not conflict with overhead obstructions such as tree limbs, wires or signs. A spot over the door would put the ladder over an opening. Under the modules the access point is blocked. A weak corner is the opposite of a strong point of construction.County of San Diego PDS 081S (2025 codes)
According to NREL, what typically causes failures of direct-buried PV conductors?
- a.Rodents chewing on them✓
- b.Ultraviolet light
- c.Heat from the inverter
- d.Voltage drop in the trench
NREL says direct-bury failures are typically caused by rodents chewing on the conductors, and that proper soil compaction helps. Buried cable is shielded from sunlight. The inverter is not near the trench and does not heat buried cable. Voltage drop wastes energy but does not damage the cable.NREL Best Practices for O&M of PV and ESS
NREL says drainage and storm-water run-off at a ground-mounted array are what?
- a.Easily corrected after commissioning by regrading
- b.Difficult to improve after the array is installed✓
- c.Handled under the module manufacturer's warranty
- d.Irrelevant to PV performance in dry climates
NREL points out that drainage and run-off are difficult to improve after the array is in place, so grade and drainage belong in the design. If they were easy to correct afterward, NREL would not stress planning them early. Poor drainage can wash out foundations and wiring, so it matters. The module manufacturer does not control the site's grade.NREL Best Practices for O&M of PV and ESS
Which kind of tracker keeps modules pointed directly at the sun throughout the day?
- a.A fixed tilt at the site's latitude
- b.A one-axis tracker following east to west
- c.A two-axis tracker✓
- d.A seasonal manual tilt
DOE says two-axis trackers allow modules to remain pointed directly at the sun throughout the day. One-axis trackers follow the sun east to west only. A fixed tilt never moves. A seasonal tilt changes only a few times a year.DOE, Solar Photovoltaic System Design Basics
According to DOE, what must the mounting structure of an array do?
- a.Last through the length of the product warranty period
- b.Let the modules shift freely whenever strong winds blow
- c.Be replaced with the inverter
- d.Support the array and resist weather for decades✓
DOE says the structure must support the array and withstand wind, rain, hail and corrosion over decades. A warranty period is far shorter than the array's life. Free movement in wind would loosen and damage the array. The structure's life is independent of the inverter's.DOE, Solar Photovoltaic System Design Basics
Which practice does NREL say reduces rodent damage to direct-buried PV conductors?
- a.Burying the cable just under the surface
- b.Proper compaction of the soil✓
- c.Using bare conductor
- d.Leaving the trench open to air
NREL says proper soil compaction is a best practice for reducing this problem. Shallow burial exposes the cable. Bare conductor is unsafe and not allowed. An open trench is a hazard and does nothing to stop rodents.NREL Best Practices for O&M of PV and ESS
When a metallic water pipe is a building's only grounding electrode, what does San Diego County's checklist require?
- a.A bonding jumper to the gas line
- b.A plastic pipe section
- c.A second water meter
- d.A supplemental electrode✓
The checklist requires a supplemental electrode where a metallic water pipe is the only grounding electrode. A second meter does not add an electrode. A plastic pipe section would break the pipe's continuity and add no electrode. A bond to the gas line is not a grounding electrode.County of San Diego PDS 081S (2025 codes)
To qualify for Solar Shade Control Act protection, how must a collector be set back?
- a.No setback applies to systems under 10 kW
- b.At least 10 feet from the property line and 5 feet above the ground
- c.At least 3 feet from the line and 3 feet above the ground
- d.5 feet from the line, 10 feet above ground✓
The Act protects a collector set back not less than 5 feet from the property line and not less than 10 feet above the ground. The two distances are reversed in this choice. 3 feet and 3 feet are less than the Act requires. The Act has no size-based exemption from the setbacks.California Public Resources Code 25982 (Solar Shade Control Act)
Compared with conduit, what trade-off does NREL describe for direct burial of conductors?
- a.The same cost, with little fault risk
- b.Higher first cost, with easier fault finding
- c.Lower first cost, with faults found at the combiner
- d.Lower first cost; faults must be dug up✓
NREL says direct burial costs less at first, but failures must be found by digging up the conductor. Direct burial is cheaper, not costlier, up front. Direct burial has a real fault risk from rodents and soil. A buried fault cannot be located from the combiner alone.NREL Best Practices for O&M of PV and ESS
A DC conduit passes down through a ceiling. Where does San Diego County's checklist require PV markings relative to the penetration?
- a.At the inverter and AC disconnect
- b.Within 1 foot above and below it✓
- c.Within 10 feet above the penetration
- d.Within 3 feet of the ceiling on one side
Markings go within 1 foot above and below penetrations of roof or ceiling assemblies, walls or barriers. 10 feet is the maximum spacing along a run, not the penetration rule. Marking only at the inverter leaves the wiring in the walls unmarked. 3 feet on one side leaves the other side unmarked and is too far.County of San Diego PDS 081S (2025 codes)
How should flashing at a roof penetration be installed relative to the roofing?
- a.So water runs under it from the roofing below
- b.So water pools behind it and waits to drain
- c.So water sheds over it onto the roofing below✓
- d.So sealant alone carries the water past the hole
Flashing is lapped so that water shed from above travels over it and onto the roofing below, never under it. Water running under the flashing reaches the opening and leaks. Pooling behind flashing drives water into the penetration. Sealant alone is not a substitute for lapped flashing.Solar Permitting Guidebook (OPR) inspection checklist
Where must a rooftop attachment anchor, according to the structural plan approach?
- a.At a convenient spot, sealed with sealant
- b.Into the shingle nailing line along the course
- c.Into the sheathing alone, wherever convenient
- d.Into framing at the plan's support points✓
The structural plan shows the location of each support and its attachment into framing, and the inspector checks structural connections against it. Sheathing alone does not carry the loads the plan calculated. The shingle nailing line holds shingles, not an array. Sealant stops water, not uplift, so it cannot justify moving an attachment.City of Berkeley 2022-code checklist
What does DOE advise owners of a solar water heater about roof penetrations?
- a.Maintain flashing and sealant as needed✓
- b.Remove the sealant and flashing each winter
- c.Replace the whole roof covering every five years
- d.Re-torque the flashing screws each month
DOE's maintenance guidance tells owners to maintain flashing and sealant around roof penetrations as needed. A fixed five-year re-roof is not DOE's advice. Removing sealant would open the penetration. A monthly re-torque schedule is not part of DOE's guidance.DOE Energy Saver, Solar Water Heating System Maintenance and Repair
NREL notes that roofing contractors often warrant their workmanship for 5 to 10 years. What should a PV installer do about that when making penetrations?
- a.Follow the roofing and racking makers' details✓
- b.Use the fastest-curing sealant on the market
- c.Drill extra holes so the rails align without effort
- d.Skip the flashing on low-slope roofs to save time
Penetrations made to the roofing and racking details keep the roof assembly as designed, which protects the roofer's workmanship coverage. Speed of cure does not make a penetration conform to the roofing details. Extra holes add leak paths and can void coverage. Low-slope roofs still need flashing and seals at every penetration.NREL Best Practices for O&M of PV and ESS
What rating does San Diego County's checklist call for on outdoor PV equipment?
- a.NEMA 2
- b.NEMA 1
- c.NEMA 12
- d.NEMA 3R✓
The checklist says exposed wiring is listed for wet location and sunlight resistant, and all outdoor equipment is NEMA 3R rated. NEMA 1 is for indoor use and does not keep out rain. NEMA 12 is an indoor industrial rating, not the outdoor requirement. NEMA 2 is an indoor rating that is not weather resistant.County of San Diego PDS 081S (2025 codes)
How should rooftop attachment points be located before the attachments go in?
- a.Space them evenly along the course
- b.Find rafters from the attic and mark to the plan✓
- c.Tap the shingles and mark the spots by their sound
- d.Use the rail length as the main guide for the spots
Attachment points come from the structural plan and the located framing, so each fastener lands in structure. Tapping the shingles is not a sound way to find framing. Even spacing ignores where the rafters actually are. Rail length does not locate framing.Solar Permitting Guidebook (OPR)
What does NREL's sample annual service checklist ask of roof penetrations?
- a.Paint over the roof penetrations
- b.Replace the flashing each year
- c.Remove the sealant to let the roof breathe
- d.Inspect that sealant is not degrading✓
NREL's checklist includes inspecting roof penetrations to be sure sealant is properly applied and not degrading. Annual replacement of every flashing is not part of the checklist. Removing sealant would open a leak path. Paint covers a problem without checking it.NREL Best Practices for O&M of PV and ESS