I have a unique question

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iwire said:
Glad to have some info from that side. :smile:

I had actually forgotten that UL prohibited wire nuts from UL listed control cabs. :smile:
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This is probably why engineers usually spec a terminal strip where I work.
 
iwire said:
Glad to have some info from that side. :smile:

I had actually forgotten that UL prohibited wire nuts from UL listed control cabs. :smile:
Click to expand...

And just wait to see the possible fate of distribution blocks and mechanical lugs. (set screw). You would not believe the problems we find using thermal imaging in systems we have esp. in non linear loads. Compression type fittings and proper terminals (cage clamp for example) are clearly outperforming traditional termination methods ? maybe a future thread
 
quogueelectric said:
This is probably why engineers usually spec a terminal strip where I work.
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No doubt, plus they look really cool. :cool:

Here is an operator panel I put together, it's not quite done in this picture.

Front_3.jpg
 
Ranch said:
And just wait to see the possible fate of distribution blocks and mechanical lugs. (set screw). You would not believe the problems we find using thermal imaging in systems we have esp. in non linear loads. Compression type fittings and proper terminals (cage clamp for example) are clearly outperforming traditional termination methods ? maybe a future thread
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That could make a good thread. I would want to learn why if the problem is only showing up on IR scans and not really causing failures is it really a problem?
 
iwire said:
No doubt, plus they look really cool. :cool:

Here is an operator panel I put together, it's not quite done in this picture.

Front_3.jpg
Click to expand...
This is heaven to a colorblind electrician like me . The only way it could get better is with Phoenix connectors. They are awesome aircraft precision crimp termination. I have them for when I need em. Btw nice work I just reread the post and apreciate nice cabinet term.
 
wirenuts arent counted in box fill but what about something like a transformer for low-voltage pendants? I installed some that are flush-mount, so the transformer, which took up almost half the jbox, was in the jbox itself.
 
iwire said:
That could make a good thread. I would want to learn why if the problem is only showing up on IR scans and not really causing failures is it really a problem?
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But we do see failures. I'll see what I can gather to post publicly ... one example is where we replaced THHN on 40+ 400A breakers with DLO to alleviate stress on connections due to expansion and contraction in the barrels of the lugs. The more flexible cable was the practical answer since the breakers could not be modified for compression fittings.

I've some good control wiring examples too, perhaps worth a visit in the forum.
 
Tomorrow -

I'll see what I can do to get some concise examples (with images) on the extent to what thermal imaging is doing for our clients as a preventative maintenance tool to identify hot spots before they become failures. Termination strategy is something we can understand.

First and foremost though, with client approval
 
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< I had actually forgotten that UL prohibited wire nuts
< from UL listed control cabs.

to Bob :

Does this mean,
that if I build-up a control cabinet from scratch ( not UL listed) ,
that I can use my own wire connecting method (such as butt splices) ?
 
glene77is said:
< I had actually forgotten that UL prohibited wire nuts
< from UL listed control cabs.

to Bob :

Does this mean,
that if I build-up a control cabinet from scratch ( not UL listed) ,
that I can use my own wire connecting method (such as butt splices) ?
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That is what I think. :)

If I am not planing on having a control cab listed I do not know of anything that would stop me from using any NEC methods inside it.

409.1 has an FPN that only mentions UL 508A, it does not require it.

Of course the customer may want us to follow 508A.
 
So to rejoin the thread, I thought perhaps a quick true story may be in order ...

I’ll call it “NEC meets UL508A in the eyes of the AHJ”

Part 1:

A tightly specified UL508A Panel, with a PLC and motor controller is assembled, tested (load tests, hi pot – the whole gamut), UL listed, shipped and installed. This is followed by a reputedly stubborn AHJ inspection. AHJ rejections are substantial. Panel maker is immediately ordered to site to rewire to AHJ satisfaction. EMT Conduits are installed inside the panel. Conductor sizes are NEC upsized for conduit runs vs. UL open air. Conduit boxes teaming with wire nuts replace wire duct and terminals. Essentially, the panel is modified so the door can be wide open, energized, safe and legal and yet everything could be concealed with the panels NEMA 12 door closed. How beautiful.

The panel maker’s field service did an excellent job, but was ordered to call someone before leaving site. (guess who?) One more task remained. Remove the UL label (dah dah dah daaaah …. Que eerie music)

If anyone is interested in part 2 let me know, it is short & sweet
 
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Ranch said:
If anyone is interested in part 2 let me know, it is short & sweet
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I am ,..I'm a bit of a junkie:wink:

Hey just for giggles do you know if your instructions are part of the listing and labeling?? This is always asked and no one seems to know.
 
Ranch said:
This is followed by a reputedly stubborn AHJ inspection. AHJ rejections are substantial.
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Here in MA the AHJ must accept listed equipment when installed per listing and labeling and of course assuming it is not a counterfeit label.
 
Ranch said:
If anyone is interested in part 2 let me know, it is short & sweet
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Since the product was modified after it left the factory, removing the UL label would be correct.

Did the AHJ then turn it down because there was no UL label on the product?
 
iwire said:
Bill, I don't want to seem rude but to me that is just nuts.

There is absolutely nothing wrong with splices in a panel. Sure it may not look as nice, but there is no safety issue or code issue.

Spend you time and effort on something more important. :)
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Waste of money.

If you want to do good, use compression splices with heatshrink. They hardly take up more room than the wires themselves and cleaner looking than wire-nuts.
 
Part 2

Part 2

Part 2:

Upon seeing the panel maker?s invoice, the outraged owner turns out to be a master with due diligence and obtains a copy of the NEC and consults with UL. Lo and behold, discovers that the two can co-exist, that the specifying engineering firm knew what they were doing. The panel as received was correct. And the contractor that installed the panel did so correctly along with every external circuit.

Subsequently, a final assessment forced the county to pay (with our tax dollars) the panel maker for the revisions and accept a panel with a disqualified UL listing.

The owner and panel maker?s relationship couldn?t be better today, and the marriage between NEC and UL at the owner?s facility is glorious

So what?s the moral of the story? Well ? that?s part 3
 
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