ECN Forum Forums Code Related Discussion NEC & other Code issues KO Seals

Yeah... All I can get are the T&B plastic ones!

Sorry, I was thinking in terms of tightness, not thickness. Are they really that thin? I see so many of them, it would probably be unfair to fail someone on them.

why market somthing unusable?
or even hard to use?
those wings can be a hazard to a panel interior wiring.

Although they're more expensive, the 2 piece (toggle type) seals are thicker and much easier to install.

Are the push in type listed? I don't think that they are.
Don(resqcapt19)

The product above is listed, and I have accepted them during my career. What's the problem anyway! Seems like the UL Standard should be reviewed before any final decisions are made. I will gaurantee that I can find some missing KO's in almost every building and if they were sealed with the seal above I would sleep very sound.

The purpose of the seal is to keep the fault inside of the enclosure, and to keep the animals, and fingers, and sticks, and rods, and, and, and, out!

Joe,

That is my poblem with this closer, with faults that often blow holes in the elclosure itself, I don't see how this item can provide "protection substantialy equivalent to the wall of the equipment"
Don(resqcapt19)

I see that we agree to disagree.

If there is going to be a hole blown in the enclosure by a fault, having a KO closer the same thickness won't prevent this or make much, if any, differance.

Is there any definiton of enclosure, especially for a type 1 enclosure, that requires it to contain a fault? The NEMA definition seems to indicate the enclosure is meant to protect the contents & prevent accidental contact. I've run across plenty of boxes that were so poorly punched that I could easily bend in the KO with my fingers.

Anyone interested in what the various NEMA types are can visit http://nema.org/engineering/papers/enclosure.html


All the enclosures provide some degree of protection against contact & appear to otherwise protect the contents of the enclosure.

Tom,
I agree with you. I did a word search for "explo" in the NEMA link and it brought up the word explosion only twice. That was for hazardous areas and in the portion comparing IEC to NEMA. All the descriptions seemed to indicate the purpose of the enclosures were to protect the components from damage caused by outside influences and prevent persons from making accidental contact. So, if the push penny accomplishes that for the classes not intended to be rainproof, waterproof, explosionproof, etc, then it provides protection substantialy equivalent to the wall of the equipment. It does seem to make a conscientious contractor cut his profit if he can't bring himself to use pushpennies instead of toggles. I doubt if it will cause him to lose a bid though.

> I've run across plenty of boxes that were so poorly punched that I could easily bend in the KO with my fingers.
I usually push them in with my thumb.

I never thought of it as a manufacturing defect.