Is SEU cable permitted for a supply side connection and the bond screw installed at the supply side disconnect and then 4 wire to the PV equipment or must the supply side PV conductors be 4 wire with an insulated neutral & EGC to the PV disconnect and no bond screw installed, or are both methods compliant?
supply side PV connection
- Thread starter mpd
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Here it appears we are debating whether a 3-wire service entrance conductor and GC/EGC bonding jumper can be installed, or should it be a 3-wire with ground and GC remain isolated from EGC.
I am agreeable to either, but I prefer the former. What say you?
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
I say that there are there are three possibilities: the AHJ may stipulate one way, the AHJ may stipulate the other way, or the AHJ may not stipulate. Find out which before proceeding.
I'm amenable to that premise! :happyyes:
I don't see where either method would be a violation, the NEC has determined these supply side conductors as feeders, in a recent technical opinion I received from NFPA in reference to grounding, NFPA responded that NEC 690.43 (A) applies and the only articles in 250 that can be enforced is 250.134 or 250.136 (A), I don't see where either of these code sections would prohibit SEU cable for a typical residential supply side connection, article 250.134 allows 250.142 that permits the grounded conductor to be used for grounding enclosures on the supply side and 230.40 exception #5 would also seem to permit this.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
it was informal in writing, NFPA said in there response that none of article 230 applies unless referred to by art. 705, and I also talked to John Wiles about this and he also said NFPA now considers these feeder conductors.
shortcircuit2
Senior Member
- Location
- South of Bawstin
Then romex is OK too...
Well I haven't had time to process that, but it sounds like someone got that all mucked up. There's no way, barring radical changes to definitions and sections, that conductors on the POCO side of a supply-side disconnect can be considered feeders. If we thought the debateability was extreme in the past, I can hardly wait to see what the 2017 edition brings if what you are saying is the case.
:blink::happyyes::happysad::lol::rant:
hmy::?wwhitney
Senior Member
- Location
- Berkeley, CA
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- Retired
So if they aren't service conductors, and they aren't feeders, they must be branch circuit conductors. The line side tap is the outlet.
Cheers, Wayne
Cheers, Wayne
:slaphead: If only we had realized this sooner.So if they aren't service conductors, and they aren't feeders, they must be branch circuit conductors. The line side tap is the outlet.
Cheers, Wayne
wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
While it sounds crazy, it is actually the best match I am aware of among the 2011 Article 100 definitions. I thought 2017 was going to clear this up, or is that wishful thinking?
Cheers, Wayne
Cheers, Wayne
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
I suspect the OP misheard, or the guy he heard it from misheard, and they were talking about the conductors between the PV disconnect and a combiner panelboard.....
the new section in the 2014 NEC 705.31 calls those conductors electric power production source conductors now, I agree it does not make much sense that PV conductors connected to the supply side become something different at that connection
the question that I submitted & response from NFPA was in reference to a supply side connection and the conductors to the supply side PV disconnect, and it was in writing from NFPA
I saw this angle coming when in 2014 705.31 was added to limit the distance from the POCC to the first OCPD to 10ft. This brought it in line with 240.21(B)(1) for taps 10ft or less in length where the size of the conductor has no relation to the supply. It's not clear in the code if 705.31 is limiting the conductor length to 10ft or just the straight line distance from the tap to the OCPD and the conductor can be longer. In the substantiation for the proposal that created the new section the proposer wrote in part, "This proposal would require short-circuit protection (cable limiters) whenever the length of unprotected cable exceeded 3m (10 ft)," which indicates that the intended interpretation is a 10ft conductor length.
Actually the proposal in my opinion is incorrect in that it assumes the conductors are feeders that should have OCPD and not service entrance conductors that do not need OCPD. If the conductors were considered service entrance conductors we would have much more flexibility.
No one should be looking at this as a good thing. Before 705.31 there was no limit to the length of the conductor between the POCC and the OCPD and I had several projects where a 10ft limit would have been a problem. Giving up the ability to install a supply side interconnection as a service entrance is a net loss for us.
Actually the proposal in my opinion is incorrect in that it assumes the conductors are feeders that should have OCPD and not service entrance conductors that do not need OCPD. If the conductors were considered service entrance conductors we would have much more flexibility.
No one should be looking at this as a good thing. Before 705.31 there was no limit to the length of the conductor between the POCC and the OCPD and I had several projects where a 10ft limit would have been a problem. Giving up the ability to install a supply side interconnection as a service entrance is a net loss for us.
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