NABCEP NEC Article 690 Applications 2 — Questions and Answers
Question 1: Under NEC 690.13, how many disconnecting means are permitted to serve as the PV system disconnecting means when the system has multiple dc circuits?
- One single disconnect for all circuits combined
- A separate disconnect for each ungrounded conductor of each dc circuit
- Up to six disconnects grouped in one location (Correct answer)
- No limit as long as each is labeled
Correct answer: Up to six disconnects grouped in one location
NEC 690.13 allows up to six disconnecting means for PV systems, consistent with the six-handle rule used in service disconnects.
Question 2: NEC Article 690 requires rapid shutdown of PV systems on buildings. What is the maximum voltage PV conductors inside the array boundary must be reduced to within 30 seconds of initiating shutdown?
- 0 V
- 30 V (Correct answer)
- 80 V
- 120 V
Correct answer: 30 V
Per NEC 690.12, conductors inside the array boundary must be de-energized to 30 V or less within 30 seconds of rapid shutdown initiation.
Question 3: For a roof-mounted PV system, what is the boundary of the rapid shutdown zone as defined in NEC 690.12?
- 1 ft from the array edges
- 3 ft from the array in all directions and 1 ft above the roof (Correct answer)
- The perimeter of the roof only
- 5 ft from the building walls
Correct answer: 3 ft from the array in all directions and 1 ft above the roof
NEC 690.12 defines the array boundary as within 3 ft of the array in all directions and 1 ft above the roof surface.
Question 4: According to NEC 690.31(A), PV source and output circuits inside a building must be contained in which of the following?
- Any listed wiring method suitable for the location (Correct answer)
- Metal conduit only
- PVC conduit only
- Type SE cable only
Correct answer: Any listed wiring method suitable for the location
NEC 690.31(A) requires PV conductors inside buildings to use listed wiring methods appropriate for the environment, not a specific type.
Question 5: What does NEC 690.13(B) require regarding the location of the PV system disconnecting means?
- It must be located at the utility meter
- It must be at a readily accessible location (Correct answer)
- It must be inside a locked electrical room
- It must be within 18 inches of the inverter
Correct answer: It must be at a readily accessible location
NEC 690.13(B) requires the PV system disconnecting means to be in a readily accessible location.
Question 6: NEC 690.56(C) requires a plaque or directory at the service entrance of a building with a PV system. What information must it convey?
- The PV array output current only
- The location of all disconnecting means including PV system disconnects (Correct answer)
- The installer's license number
- The system's annual energy production estimate
Correct answer: The location of all disconnecting means including PV system disconnects
NEC 690.56(C) mandates a plaque at the service entrance indicating the location of all PV system disconnecting means for emergency personnel.
Question 7: Under NEC 690.15, a disconnecting means must be provided to isolate PV equipment such as inverters and charge controllers. Where must this disconnect be located?
- At the utility interconnection point
- Within sight of or integral to the equipment it isolates (Correct answer)
- At the main service panel only
- At the PV array combiner box
Correct answer: Within sight of or integral to the equipment it isolates
NEC 690.15 requires equipment disconnects to be within sight of or integral to the equipment being isolated, ensuring safe maintenance.
NABCEP NEC Article 690 Applications 2
Under NEC 690.13, how many disconnecting means are permitted to serve as the PV system disconnecting means when the system has multiple dc circuits?