CSLB C-46 Solar (Trade Exam) — All Questions
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70 questions
What does San Diego County's checklist require to keep stand-alone battery spaces safe from gas buildup?
- a.A fan that runs in summer months
- b.Ventilation suited to the battery technology✓
- c.A window in the wall, whatever the battery type
- d.None; the room has a working door and lock
The checklist calls for ventilation appropriate to the battery technology, inside a lockable enclosure or room. A door does not ventilate gases. A window cannot be counted on for every battery type. Seasonal fan use does not match gas production.County of San Diego PDS 081S (2025 codes)
How must all battery systems be treated under San Diego County's stand-alone rules?
- a.Stacked without a rack
- b.Placed in the driving path of the garage
- c.Left exposed so leaks are visible
- d.Protected from damage✓
All battery systems must be protected from physical damage. Exposure invites damage. The driving path is where vehicle strikes happen. Unracked stacking risks falls and damage.County of San Diego PDS 081S (2025 codes)
How does NREL say field battery life compares with manufacturers' literature?
- a.About ten times longer than the literature says
- b.About double, thanks to careful use and cooling
- c.About half, from heat and low charge✓
- d.The same as the literature says
NREL says field life is often about half of the literature figure, most likely due to overheating and long periods at low state of charge. Field life is not longer than the literature figure. Real-world conditions rarely match the literature exactly. Ten times longer is not plausible.NREL Best Practices for O&M of PV and ESS
Sandia compares 100 amps of short-circuit current in a large PV system to what?
- a.A 600-volt open-circuit condition✓
- b.A 12-volt car battery under a hood
- c.A 24-volt low-voltage thermostat circuit
- d.A 120-volt household lighting circuit
Sandia says 100 amps of short-circuit current can be as difficult to handle as an open-circuit voltage of 600 volts. A 12-volt battery is not comparable in hazard. A 120-volt circuit understates the comparison. A thermostat circuit is a very low-power circuit.Sandia, PV Power Systems and the NEC: Suggested Practices
A 12 kWh battery bank allows use of 80 percent of its rated capacity. How much energy is usable?
- a.9.6 kWh✓
- b.0.96 kWh
- c.15 kWh
- d.11.2 kWh
Usable energy is 12 x 0.80 = 9.6 kWh. 15 kWh divides by 0.80 instead of multiplying. 11.2 kWh subtracts 0.8 kWh rather than 20 percent. 0.96 kWh moves the decimal point one place.Stand-alone battery sizing (CSLB C-46 outline)
According to Poway's compliance list, what words open the label placed at service equipment?
- a.SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN✓
- b.SOLAR ARRAY SHUTS ITSELF OFF AT NIGHT
- c.ROOF POWER IS OFF WHEN THE MAIN SWITCH IS OFF
- d.SOLAR SYSTEM IS DISCONNECTED FROM THE UTILITY GRID
The list gives the words SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN, followed by the instruction to turn the switch to OFF. The array does not shut itself off at night through this system. Roof power is not simply off whenever the main switch is off; the label names rapid shutdown. This wording does not state that rapid shutdown is installed.City of Poway 2022-code list (CEC 690.56(C))
What colors does the Guidebook's label table give for the rapid shutdown label?
- a.White lettering on a blue background
- b.Red lettering on a white background
- c.Red background, white lettering✓
- d.Black lettering on a yellow background
The label table calls for a red background with white lettering. Black on yellow is not the stated scheme. Red on white reverses the colors. Blue is not the stated background.Solar Permitting Guidebook (OPR) label table
What must an alternate power source placard be made of under San Diego County's checklist?
- a.Paper in a clear plastic sleeve, zip-tied on
- b.A handwritten tag on laminated weatherproof card
- c.A printed vinyl sticker with adhesive backing
- d.Engraved metal or plastic in a contrasting color✓
The placard must be metal or plastic with engraved letters in a contrasting color. Paper in a sleeve fades and tears outdoors. A printed sticker is not engraved and is not durable enough. A handwritten tag is not permanent.County of San Diego PDS 081S (2025 codes)
What must the warning label required with a breaker positioned under a power control system or busbar rule tell people?
- a.The breaker may be moved whenever service needs room
- b.The overcurrent device must never be relocated✓
- c.A solar array is on the roof above this panel
- d.The main breaker is on the left side of the panel
San Diego County's checklist cites a warning not to relocate the overcurrent device at the power source output connection, so no one moves the breaker and defeats the busbar calculation. Moving the breaker for service is exactly what the warning forbids. A note that an array is on the roof describes the array, not the breaker restriction. The main breaker's side of the panel is a location note, not a warning against relocating.County of San Diego PDS 081S (2025 codes)
Besides being visible after installation, what must PV labels be?
- a.Removable for easy inspection by anyone
- b.Suited to its environment✓
- c.Printed in at least two languages
- d.Mounted on the inverter enclosure
Labels must be visible after installation and suitable for the environment where installed. Labels must stay put, not come off. Two languages are not required by this rule. Labels belong on raceways, boxes and equipment, not just the inverter.City of Berkeley 2022-code checklist (CEC 690.31)
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When should polarity be verified during commissioning?
- a.Never; connectors prevent any reversal
- b.Once a year, after commissioning, at the annual visit
- c.At all combiners and inverter inputs, before switching on✓
- d.After the inverter is energized and running
Polarity is checked at every combiner, disconnect and inverter input before any switch is closed so reversed wiring cannot damage equipment. Checking after energizing risks damaging the inverter. An annual check alone is too late to protect equipment at startup. Connectors do not ensure correct conductor assignment.NREL Best Practices for O&M of PV and ESS
What does a rapid shutdown test at commissioning confirm?
- a.That the utility meter is sealed and read
- b.That modules produce full rated power at noon
- c.That shutdown makes devices respond✓
- d.That the main breaker trips on a bolted overload
The test initiates rapid shutdown and confirms the equipment responds as required. Rated power is a performance matter, not a shutdown test. Meter sealing is the utility's concern. Overload tripping is a breaker test, not a rapid shutdown test.Solar Permitting Guidebook (OPR) inspection checklist
At turnover, which items should the installer show the owner how to find and use?
- a.The module serial numbers printed on the roof
- b.The utility's pole-mounted transformer
- c.The shutdown switch and emergency disconnects✓
- d.The monitoring app login and password
Educating the client includes where the shutdown switch and emergency disconnects are and what the labels mean. The transformer belongs to the utility and is not for the owner to operate. A login alone does not teach safe shutdown. Serial numbers are paperwork and not safety controls.NREL Best Practices for O&M of PV and ESS
What governs the inverter's grid settings at commissioning?
- a.The customer's preference for self-consumption
- b.The racking manufacturer's installation instructions
- c.The module manufacturer's published data sheet
- d.The utility's interconnection approval requirements✓
Inverter settings follow the utility's interconnection approval under Rule 21. A module data sheet describes modules, not grid behavior. Racking instructions cover the mounting system. The customer cannot choose settings the utility requires.CPUC Rule 21 (Electric Rule 21 overview)
NREL recommends giving the homeowner what at turnover?
- a.A full set of the utility's current rate tariffs
- b.The installer's business tax records for the job
- c.A manual with contacts, indicators and procedures✓
- d.The roof structural calculations for the array
NREL recommends a manual with contact information and a description of operational indicators and procedures the homeowner can do. Tax records are not operating information. Structural calculations alone do not teach operation. Tariffs do not help the owner run the system.NREL Best Practices for O&M of PV and ESS
When is string operating current measured during commissioning?
- a.Once a year after the owner moves in
- b.Before any switch is closed at the combiner
- c.Once the inverter runs, per string✓
- d.While the array is covered by a tarp
Operating current can only be read with the array delivering power, so it is measured once the inverter is running. With no switch closed there is no operating current to read. A covered array produces no meaningful current. Waiting a year would miss installation faults.NREL Best Practices for O&M of PV and ESS
Which settings are configured at commissioning for a storage system?
- a.Roof pathway widths and ridge setback sizes
- b.Label font sizes, colors and wording rules
- c.Module tilt angles and tracker travel limits
- d.Backup reserve, self-consumption, export limits✓
Storage modes such as backup reserve, self-consumption and export limits are set at commissioning. Tilt is a mechanical matter set at installation. Pathway widths are layout decisions. Label sizes are code items, not inverter settings.NREL Best Practices for O&M of PV and ESS
What should the owner be told about a sudden drop in output in the monitoring portal?
- a.It means the portal is broken
- b.It deserves a service call✓
- c.It is normal seasonal variation
- d.It matters after a full year
Output declines slowly, so a sudden drop points to a problem worth a call. Seasonal change is gradual, not sudden. A drop in measured output is not assumed to be a portal error. Waiting a year leaves a fault running.NREL Best Practices for O&M of PV and ESS
If a listed power control system is used for the busbar calculation, how is its setting treated?
- a.As the main breaker's rating
- b.As the inverter's peak surge rating
- c.As unimportant; it can be changed freely
- d.As the design source current, and it is labeled✓
The PCS setting is considered the power-source output circuit current, so it is a design value and is labeled. An arbitrary change would defeat the busbar calculation. Surge rating is a different figure. The main breaker has its own rating.County of Lake 2022-code excerpt (CEC 705)
Which paperwork should the owner receive at turnover?
- a.The installer's payroll records for the crew
- b.Manuals, warranties, utility approval✓
- c.The inspector's personal field notes on the job
- d.The crew's individual training and safety logs
The owner needs the manuals, warranties, the interconnection approval and, for storage, the maintenance provider's contact label. Payroll records belong to the contractor's business. Training logs are internal. An inspector's notes are not owner documents.NREL Best Practices for O&M of PV and ESS