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Solution for Hole Made on an EX "d" JB
How to repair a hole on an EX "d" certified JB for nameplate

I have made a mistake by making a hole on an EX "d" certified JB for nameplate changing. The nameplate's hole was measured wrong, leading to making a hole on the JB. Kindly provide a solution...

By W.L. Mostia on 11 October, 2018 - 9:39 am
1 out of 1 members thought this post was helpful...

Since you are screwing holes in the EX "d" JB for your nameplate, I hope that you are aware that you may be violating the JB's ED "d" approval (unless the JB is approved for drilling holes in it by the user). I assume you checked with the JB box manufacturer before you started drilling holes in the box. They should have been able to tell you what to do in this case.

That being said, if the box is approved for drilling holes in it, what I have seen people typically do is put a steel (stainless if outside) screw in it and make sure that you have at least 5 threads engaged and be as long as the hole is deep. Any nameplate screws should be at least " away from any other screw hole and the nameplate screws must have the 5 screw threads engaged too just like the extra hole you drilled.

William (Bill) L. Mostia, Jr. PE
ISA Fellow
Winner of the 2017 ISA Raymond D. Molloy Award

Sr. Functional Safety Consultant
SIS SILverstone, LLC

http://sissilverstone.com

1 out of 1 members thought this post was helpful...

The one and only solution is the one you apparently don't want to hear as you are posting here on a forum.

You have to order a new JB as the certificate has became invalid. Therefore juridically the installation is compromised in case of a major incident.

1 out of 1 members thought this post was helpful...

More likely just a new front cover for the JB.

Thank you for your opinion...

Yes, you should have used an adhesive label or used stencils and paint to label the front cover.

That being said there are external plugs for gland holes sold for Ex d boxes, so you may be able to tap the wrong holes and plug them with a machine screw. You should consult the supplier or manufacturer.

M20 Exd/Exe Stopping Plug: 316 Stainless Steel (Type U)
https://www.threadtoolsupply.com/m20-exd-exe-stopping-plug-316-stainless-steel.html

good luck

0 out of 1 members thought this post was helpful...

Thanks, @dwpatterson for your opinion. But actually the hole is not on the side or bottom of the JB, so i cant drill a hole on the front face of JB M20 size and plug it with a gland plug...

2 out of 2 members thought this post was helpful...

>Thanks, @dwpatterson for your opinion. But actually the
>hole is not on the side or bottom of the JB, so i cant drill
>a hole on the front face of JB M20 size and plug it with a
>gland plug...

I was not suggesting that you drill and tap to M20, but just that you could use the same technique and drill and tap to M6, M8, M10 or whatever drill size and tap matches the hole you need to plug.

good luck

Thank you all for your timely opinion...

2 out of 2 members thought this post was helpful...

Remember, in engineering opinions lead to high risk designs, most advice here comes from experience and engineering standards. In your case the approval ratings of the JB are violated, that is it is not tested or re-certified, at a minimum you need to contact the supplier.

The last thing you want is a JB that causes and explosion or fire, and you were the man that "fixed it".