photovoltaic grounding

[sparky1978]

I am currently doing a design for a 3kw system. I am using the SMA sunny boy SB3000 with integral disconnect. The disconnect has a termination for the equipment ground from the AC distribution panel located on the AC side. For DC there is a termination for the Frame of the PV array and a termination for the Bonding jumper to the grounding electrode. See page 15 on attached.



My question is:

If an AC grounding electrode already exists, then can I run a GEC from the termination point in the disconnect shown on the right in page 15 with the AC conductors to the AC panel and connect to the Ground bar in the AC panel. Would this satisfy 690.47? Examples I see show either a bare copper conductor or an insulated conductor running in a separate conduit from the DC electrode to the AC electrode. Hopefully my question isn’t confusing. Thanks.



Nick

 

[7anoter4]

In the following article is a reference to this question:

http://www.iaei.org/subscriber/magazine/05_b/wiles.htm

Here is an extract from "Grounding System Clarification" paragraph:

"The Code allows the dc grounding electrode conductor to be routed to one or two locations: (1) to a dc grounding electrode which then must be bonded to the ac grounding electrode, or (2) directly to the ac grounding electrode where it is connected to that electrode with a separate clamp."
I think if the dc grounding is connected directly to the ac grounding electrode this will be according to NEC 690.47.

 

[jfpe]

Sparky,
It sounds like you are planning to connect the DC grounding electrode conductor only to the grounding bar in the AC panel and not to the existing building ground. This is not enough to satisfy 690.47. You need to connect to the existing building ground rod. Also, keep in mind the GEC needs to be continuous. Don't cut it to make a connection in the AC panel.
John