NEMA 12 - Riveted nameplate OK?

[OEMsparky]

Is it acceptable to rivet nameplates to the side of an electrical enclosure when trying to maintain NEMA 12 or NEMA 4/4X ratings? Does anyone know of a good practical reference to best practices when striving to maintain these ratings?

Thanks.

 

[jraef]

Technically, no! ANY penetration to that enclosure must be done in a manner consistent with the NEMA/UL test standards, and in the case of UL listing, must also be UL listed for the same rating. So you can punch a push button hole in a UL Type 4 box and install a UL Type 4 rated push button, but if you install a Type 12 button you have violated the enclosure rating.

In reality though, I seriously doubt anyone will make a fuss over a rivet (or 4), especially if you put a dollop of silicone seal on it first.

JRaef.com
Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[dpc]

I basically agree with jraef, but I'd be a little concerned about a NEMA 4 panel with a riveted nameplate - that firehose test might push more water through there than might be expected. If I really needed watertight, I'd avoid any unnecessary holes.

I wouldn't worry much about NEMA 12.

 

[itsmoked]

Also 'Pop' rivets have holes thru the middle!!

I can't believe there isn't some adhesive that would require the tearing of the box or the label to effect removal and hence would cause no penetrations. 3M 5200 for starters.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[LionelHutz]

It's really not a good idea with 4 or 4X enclosures. As mentioned, they're tested for leaks using a firehose and even gasketed joints will leak. Siliconed holes leak. In fact, if you've ever done testing it seems like almost everything leaks the first time.

There are UL approved label material and manufacturers that make peel and stick labels that you can laser print and they are very durable. About the only way to destroy them is to apply a lot of heat and burn/melt them.

 

[felixc]

Do not use cheap rivets. If your enclosure is metallic, over time you can also get galvanic corrosion on the rivet that may let the water go through. Make sure that the metals are compatible. Aluminum rivets on steel enclosures are a no-no.

 

[ScottyUK]

Re. pop rivets have holes in them: stainless steel rivets with no through hole are available in marine wholesalers.

Making enclosures too well sealed can lead to its own set of problems: water can enter in the form of vapour as the enclosure 'breathes' due to heating and cooling over the day and night, and though atmospheric pressure changes. Once in it can't get out. Better to use either a pressure tight enclosure - IP68 - or to install a breather on the lowest face of the enclosure. NEMA 4 equates roughly to our IP65 or IP66 depending on which comparison chart you believe: IPx6 is the worst for allowing gradual ingress through the breathing mechanism.


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