Revision as of 22:34, 15 September 2023

NEC 690 - Covers PV Systems

690.41 - Equipment Grounding Conductor requirements [1]
- 690.41(B) also requires ground fault protection except if there are no more than 2 strings (PV source circuits [2])
  - Since NEC 2020, ground fault indicator must be readily visible (but not necessarily readily accessible?) [3]
- 690.45 - size of PV equipment grounding conductors - Table 250.122 + no less than 14 ga.
690.9(A) says that we don't need overcurrent device for PV if the wires can handle short current capacity of PV. But good luck trying to convince a code official.
PV Grounding PDF [4]. Although the NEC does not specifically require all equipment to be certified/listed, many local jurisdictions and many AHJs establish requirements that all equipment be certified/listed because they feel unqualified to examine uncertified/unlisted equipment for safety as the NEC requires.
- Good overview doc. Read it from p. 6 on to understand equipment ground, system ground.
- Additional issue for PV is that in cloudy conditions, if you get a fault, a breaker may not trip because current is too low. For this reason, extra ground fault protection devices may be required.

PV panels should follow electrical grounding conductor sizes - [5]
Ie, for 30A DC, we need 10 ga ground.
PV frames must be connected to PV system equipment grounding conductor [6]
After leaving the PV array, the equipment ground must run together with the power wires. [7]

Australia rules - appear to say 6 ga for lightning protection, and 12 ga for frame grounding [8]
6 ga USA if 'subject to damage'?

@@ Line 2: / Line 2: @@
 *690.41 - Equipment Grounding Conductor requirements [https://codes.iccsafe.org/content/ISEP2018/national-electrical-code-nec-solar-provisions#ISEP2018_NEC_Sec690.41]
 **'''690.41(B) also requires ground fault protection''' except if there are no more than 2 strings (PV source circuits [https://www.e-education.psu.edu/ae868/node/965#:~:text=A%20PV%20source%20circuit%20is,usually%20only%20one%20source%20circuit.])
+***Since NEC 2020, ground fault indicator must be readily visible (but not necessarily readily accessible?) [http://www.codebookcity.com/codearticles/nec/necarticle690-5.htm]
 **690.45 - size of PV equipment grounding conductors - [[Table 250.122]] + no less than 14 ga.
 *690.9(A) says that we don't need overcurrent device for PV if the wires can handle short current capacity of PV. But good luck trying to convince a code official.