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Dennis Alwon said:
I would like to add that it is not just the termination that needs to be rated 75C, I believe many panel lugs are 90C rated, but the equipment must be rated 75C. The 90C lugs in my example will not help if the equipment is not rated 90C and it won't be.
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In my example above, is it required that the 90C splices be accomplished in separate enclosures?

Or could I use a Polaris Insultap within the gutter space of a 75C rated panelboard or disconnect, and take credit for the Insultap's 90C rating?

Because the insultap is not a manufactured part of manufactured product. It is a field-installed connector.
 
Carultch said:
In my example above, is it required that the 90C splices be accomplished in separate enclosures?
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I don't see why an enclosure is necessary if you do as you say below.

Or could I use a Polaris Insultap within the gutter space of a 75C rated panelboard or disconnect, and take credit for the Insultap's 90C rating? Because the insultap is not a manufactured part of manufactured product. It is a field-installed connector.
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I can't see why that would be an issue as long as the panelboard has the req. space. 312.8
 
iwire said:
When I suggested this method a long time ago Smart pointed out the enclosure must be rated 90c.
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I thought about that and I used some common sense as to why it would need to be 90C if the conductors were not terminated there. I guess strictly per code he would be correct but it would make no sense
 
Dennis Alwon said:
I thought about that and I used some common sense as to why it would need to be 90C if the conductors were not terminated there. I guess strictly per code he would be correct but it would make no sense
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I am not sure what code section he based that on but it has nothing to do with the 'panelboard' it has to do with the cabinet/enclosure enclosing the panelboard.

I can see this being an issue if using a PVC JB for the splice but why a metal cabinet would not have a 90 c rating I just don't understand.

Maybe Smart will jump in here.

There is also the question of how much conductor you need between the breaker and the splice. Apparently UL uses 3' of conductor for testing purposes but the code is silent on the issue.

Could I use as little as a couple of inches of larger conductor at the breaker? :?
 
iwire said:
I am not sure what code section he based that on but it has nothing to do with the 'panelboard' it has to do with the cabinet/enclosure enclosing the panelboard.
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Yeah I got that and that was my point. The box is made by a tin knocker who probably makes the same JB's with the same materials.??

I can see this being an issue if using a PVC JB for the splice but why a metal cabinet would not have a 90 c rating I just don't understand.
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I am not convinced a PVC box is an issue either.

There is also the question of how much conductor you need between the breaker and the splice. Apparently UL uses 3' of conductor for testing purposes but the code is silent on the issue.
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I vaguely remember this and it makes sense but we have no guidance on it.
Could I use as little as a couple of inches of larger conductor at the breaker? :?
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Well probably not since technically I think smart is correct that the equipment must be 90C rated and that would eliminate the panelboard. I suspect this has not been examined much by the cmp.
 
I have check a few sites and none of them give a temp. rating for their boxes including Hoffman. I wonder if the rating is inside the box
 
I'm pretty certain I have seen temp rating on PVC raceways and fittings. I imagine it is because they are physically effected by much lower temperatures then the same item is if constructed with almost any metallic base.

I would think a steel cabinet can take a much higher temperature then many of the components it contains when it comes to panelboards, control cabinets, etc, especially if it is just unpainted galvanized steel.
 
kwired said:
Im pretty certain I have seen temp rating on PVC raceways and fittings. I imagine it is because they are physically effected by much lower temperatures then the same item is if constructed with almost any metallic base.

I would think a steel cabinet can take a much higher temperature then many of the components it contains when it comes to panelboards, control cabinets, etc, especially if it is just unpainted galvanized steel.
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You may have IDK but I have a jb that has no temp rating. So do I use 60C for under 100 amps?. Sorry but I can see some sense in this but not at all consistent for all situations. Maybe UL has something on this

I see nothing in the whitebook
 
Dennis Alwon said:
Yeah I got that and that was my point. The box is made by a tin knocker who probably makes the same JB's with the same materials.??

I am not convinced a PVC box is an issue either.

I vaguely remember this and it makes sense but we have no guidance on it.
Well probably not since technically I think smart is correct that the equipment must be 90C rated and that would eliminate the panelboard. I suspect this has not been examined much by the cmp.
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Dennis Alwon said:
You may have IDK but I have a jb that has no temp rating. So do I use 60C for under 100 amps?. Sorry but I can see some sense in this but not at all consistent for all situations. Maybe UL has something on this

I see nothing in the whitebook
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For PVC conduit and fittings see 352.10(I).

Now I understand that does not cover PVC j-boxes but I am willing to bet that PVC boxes have conductor temperature limitations as well.

90C is 194F and I doubt a PVC box does well at 194F.

Put that J-box in your oven at 190-200 and see how soft it gets.:)
 
I know I've seen 90C marked on PVC conduit many times not so certain I have seen it on boxes and fittings - but can't imagine they can hold up to much more temp then the pipe can.
 
kwired said:
I know I've seen 90C marked on PVC conduit many times not so certain I have seen it on boxes and fittings - but can't imagine they can hold up to much more temp then the pipe can.
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The box only needs to be able to be 90C not any higher. If the conduit can do it- heat will build up there more than at the box- I think then the box should be able to but with no rating on it I am not sure what to think. I only check a Scepter box- UL listed but made in Canada
 
Dennis Alwon said:
The box only needs to be able to be 90C not any higher. If the conduit can do it- heat will build up there more than at the box- I think then the box should be able to but with no rating on it I am not sure what to think. I only check a Scepter box- UL listed but made in Canada
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For some reason it seems most PVC fittings are/have always been from Canadian companies except maybe Carlon.
 
Esthy said:
50% says YES, AWG 4 THHN can be use as a feeder for a 100 amps sub-panel and 50% says NO for a separated garage/shop. I am in doubt, but I would like to use it as I have a full spool and I am donating it.
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This may come from earlier code cycles where the wording was different and it was argued by some as to when the reduced wire size applied. Around here in Central NY (where most "electricians" are not real electricians), I see the reduced wire sizes used everywhere in residential work. In fact I dont recall ever seeing a resi sub panel feeder sized off 310.16! So if you are in CNY and you see a 90 amp feeder with 4 CU or 2 AL, to a sub in a dwelling, I probably did it ;)
 
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