690 equipment ground vrs bonding vrs grounding.

[Larry Akers]

It use to say if subject to a lighting strike minimum size ground should be a #8. Article 690.47 (C)(3) states minimum size the larger of 250.122 or 250.166. in article 250.166 (A) AND (B) states minimum #8. 250.122 shows that 15 amp could use as small as a # 14 wire. So what size would be the minimum size of the ground wire from the PV panel to earth. Would it be #8 from earth to the inverter or all the way to the panel. Or from the panel to the inverter be considered a equipment ground. Thanks for any clarification.

 

[starbolin]

Sorry, but there is not enough information in the question to give a specific answer. The subject matter covers large portions of both Article 250 and Article 690. Is the PV array itself a listed system? Are the system outputs AC or DC or both? Interactive, hybrid, or standalone? Are the PV cell mountings used as a DC buss? What is the raceway type used between the PV array and the inverters? Is there access to the PV array?

 

[Larry Akers]

A listed PV panel and rails system, down thru the disconnect, inverter and to the main panel (all listed parts). Assume no micro inverters and not a listed system.

The GEC for PV systems are covered in 690.47.
Generally, this sends the user to 250.166. Section 250.166(A) and (B) are for
the GEC of a DC system. Unless (A) applies, the GEC is required to be a minimum
of 8 AWG copper or the largest conductor size.

The EGC of PV systems are covered in 690.45.
This general rule is that the EGC size is based on 250.122.

So what would the minimum size wire that bonds or grounds the PV rack and PV panels to the main?
I guess the better question is what do you call this wire?

 

[Smart $]

... I guess the better question is what do you call this wire?

Well it isn't just a wire. You are trying classify the pathway as one wire... when it is a system comprised of more than one. 690.45 and 690.46 deal with EGC's... 690.47 deals with GEC's.