[RE-wrenches] What is a "direct-current system"?

[Dave Click]

Peter, (back to the Wrenches list)

Yep, 690.47(C) would apply to conventional grid-tied no-battery systems. 
Sorry for the litany of code references:

690.47(C)(7) does refer to 250.166. As I understand it, you need to size 
your GEC from your Xantrex ground bar (690.47(C)(5)) per 250.66 and 
250.166 (pick whichever requires the larger conductor), as required in 
690.47(C)(7). Note that when you're running your AC EGC in the Xantrex 
units, the installation guide (last I checked) required you to actually 
run that EGC from the ground bar rather than what looks to be the AC EGC 
terminal.

DKC


-------- Original Message --------
Subject: Re: [RE-wrenches] What is a "direct-current system"?
From: Peter Parrish <peter.parrish at calsolareng.com>
To: 'Dave Click' <daveclick at fsec.ucf.edu>
Date: 2009/6/19 14:12

> No, the inspector is saying that 690.47(B) applies, and as a consequence,
> 250.166 applies. He didn't mention 690.47(C).
> 
> Dave,
> 
> I see your point: all conventional grid-tied V systems fall under (C). But
> (C) refers to its own set of requirements 690.47(C) (1) through (8) and not
> 250.166. So which to we follow/
> 
> - Peter
> 
>                                                      
>  Peter T. Parrish, Ph.D., President
> California Solar Engineering, Inc.
> 820 Cynthia Ave., Los Angeles, CA 90065
> CA Lic. 854779, NABCEP Cert. 031806-26
> peter.parrish at calsolareng.com  
> Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
> 
>  
> -----Original Message-----
> From: Dave Click [mailto:daveclick at fsec.ucf.edu] 
> Sent: Friday, June 19, 2009 10:50 AM
> To: peter.parrish at calsolareng.com
> Subject: Re: [RE-wrenches] What is a "direct-current system"?
> 
> Peter- Do you mean that since there is a DC circuit as well as an AC 
> circuit, 690.47(*C*) applies? Then 690.47(C)(7) would require your GEC 
> to meet the requirements of 250.66 & 250.166.
> 
> I didn't CC the wrenches here, just checking to clarify what you're 
> looking for. I assume that 690.47(A) and (B) being separately listed 
> like that means that 690.47(A) would apply to anything but DC-direct 
> systems, 690.47(B) would apply to everything but AC module systems, and 
> then 690.47(C) is there to clarify that you need to worry about both (A) 
> and (B) for most systems.
> 
> DKC
> 
> -------- Original Message --------
> Subject: [RE-wrenches] What is a "direct-current system"?
> From: Peter Parrish <peter.parrish at calsolareng.com>
> To: 'RE-wrenches' <re-wrenches at lists.re-wrenches.org>
> Date: 2009/6/19 12:55
> 
>> I have a LA Dept. of B&S inspector cite Article 690.47(B) 
>> "Direct-Current Systems" and its consequent grounding requirements 
>> (250.166(A)(B)) in connection with a very straightforward grid tied PV 
>> system (i.e. no batteries, just PV and a Xantrex GT inverter).
>>
>>  
>>
>> He said that since there is a DC circuit as well as an AC circuit, 
>> 690.47(B) applies. I countered that all PV systems have a DC circuit, so 
>> to separately call out a "Direct-Current System" must apply to something 
>> other than the DC PV circuit inherent in all PV systems.
>>
>>  
>>
>> Am I missing something here? Is "Direct-Current System" defined in 
>> Article 690? We are working off NEC 2008.
>>
>>  
>>
>> Thanks in advance for your help.
>>
>>  
>>
>> -          Peter
>>
>>  
>>
>> Peter T. Parrish, Ph.D., President
>> California Solar Engineering, Inc.
>> 820 Cynthia Ave., Los Angeles, CA 90065
>> CA Lic. 854779, NABCEP Cert. 031806-26
>> peter.parrish at calsolareng.com <mailto:peter.parrish at calsolareng.com> 
>> Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885      
>>
> 
>>  
>>
>>  
>>
>>
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