Photovoltaic question

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Dennis Alwon said:
I agree
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Just to be clear. There is no metal conduit....the 1000 volt DC conductors are in a cable tray that extends from one array to the other with the 600 volt insulated conductor bonding the tray and the racking....then from the racking to the combiner box ground bar.
 
shputnik said:
Just to be clear. There is no metal conduit....the 1000 volt DC conductors are in a cable tray that extends from one array to the other with the 600 volt insulated conductor bonding the tray and the racking....then from the racking to the combiner box ground bar.
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I was agree that it was strange... I didn't pay any mind to conduit comment because it didn't matter anyway.
 
shputnik said:
Not talking about the equipment grounding conductor. I'm referring to the 600 volt thhn Insulated conductor bonding the racking, cable tray. If the DC conductors are 1000 volt insulated would there be an issue on a fault if the conductor bonding the metal had a 600 volt rating
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No issue.

And you are talking about an equipment grounding conductor. That's what the conductor bonding the racking and cable tray is called.
 
The reference to 300.3(C) is for conductors of different systems and does not apply at all. As ggunn and jaggedben stated you ARE talking about the EGC and it CAN be bare so who cares if it is rated 600v send it.....
 
gadfly56 said:
So, do we have the bizarre situation where if the conductor is bare, you're fine, but if you put insulation on it, now it has to be listed for 1,000 volts? :unsure:
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Is that any different then if you run conduit, say emt, and have a 30 amp circuit then you don't need an equipment grounding conductor however, if you choose to run it then it must be rated 30 amps. You can't just run a 20 amp wire.

I know it's not the same but it is a similar concept.
 
gadfly56 said:
So, do we have the bizarre situation where if the conductor is bare, you're fine, but if you put insulation on it, now it has to be listed for 1,000 volts? :unsure:
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What system are you using that is 1000v, I was assuming this to be residential due to the NEC references. And again be careful of the NEC headers when you are looking these up. The reference in 300.3 was from "Conductors of different systems". Do you in fact have different systems in this raceway? Most of my experience is in utility and we did not use PV grounding conductors which did drive us to use loom where it was exposed to sunlight (and to protect the conductors from the purlin edges). In residential I don't know of a system using 1000v other than the modules themselves.
 
BradPV said:
What system are you using that is 1000v, I was assuming this to be residential due to the NEC references. And again be careful of the NEC headers when you are looking these up. The reference in 300.3 was from "Conductors of different systems". Do you in fact have different systems in this raceway? Most of my experience is in utility and we did not use PV grounding conductors which did drive us to use loom where it was exposed to sunlight (and to protect the conductors from the purlin edges). In residential I don't know of a system using 1000v other than the modules themselves.
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The OP specifically asked about 1,000 volts.

Even if you don't have different systems, the insulation has to be good for the voltage of the ungrounded conductors, right? You wouldn't use THHN on such a system.
 
I run THWN-2 ground wires with 2000V PV wire all the time and I have never had an AHJ challenge it.
 
ggunn said:
I run THWN-2 ground wires with 2000V PV wire all the time and I have never had an AHJ challenge it.
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As a matter of practicality, it may make no difference, but THWN-2 is listed only to 600 volts. Is it technically a violation?
 
gadfly56 said:
As a matter of practicality, it may make no difference, but THWN-2 is listed only to 600 volts. Is it technically a violation?
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I know, and I don't think so. I think that if it were, someone would have brought it up. I have designed over 100 commercial PV systems in many jurisdictions, and some of them are real sticklers over fine points in the code.
 
gadfly56 said:
The OP specifically asked about 1,000 volts.

Even if you don't have different systems, the insulation has to be good for the voltage of the ungrounded conductors, right? You wouldn't use THHN on such a system.
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But, why does the voltage matter for the EGC? It just needs to be sized appropriately.....
 
Dennis Alwon said:
Is that any different then if you run conduit, say emt, and have a 30 amp circuit then you don't need an equipment grounding conductor however, if you choose to run it then it must be rated 30 amps. You can't just run a 20 amp wire.
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That's the conventional wisdom, but I'm not sure I buy it. If you run emt as your EGC, and the circuit inside is on a 30A breaker, then if you have a #12 Cu green wire inside, I agree the green wire is not an adequately sized EGC. But that just makes it an extra green wire you felt like having that is bonded at both ends to the EGC; the EMT is still your EGC. What section prohibits that extra green wire?

Cheers, Wayne
 
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