Practice of explosion proof enclosures

[Ramirez001]

Hello All,

I'm new to the forum, but quite often visit it. If this questions has been asked in a different post, please let me know so you don't have to waste your time answering the question.

I wanted to see what you guys thought of the practice of using explosion proof enclosures in Div 1 areas, stuffing it with my components and calling it done as opposed to going through an NRTL to certify my equipment "system"? Is this practice acceptable? and have any of you experienced an AHJ rejecting your installation for doing the same? If this is an acceptable practice, I would assume then that someone (at one point or another) would have to assess the components placement for pressure piling and electrical safety?

Thanks for your insight.

All the best,

 

[petersonra]

Hello All,

I'm new to the forum, but quite often visit it. If this questions has been asked in a different post, please let me know so you don't have to waste your time answering the question.

I wanted to see what you guys thought of the practice of using explosion proof enclosures in Div 1 areas, stuffing it with my components and calling it done as opposed to going through an NRTL to certify my equipment "system"? Is this practice acceptable? and have any of you experienced an AHJ rejecting your installation for doing the same? If this is an acceptable practice, I would assume then that someone (at one point or another) would have to assess the components placement for pressure piling and electrical safety?

Thanks for your insight.

All the best,

That is generally the way it is done. As long as the assembly is not required to be listed, it is probably OK. No doubt people can come up with things that are not but the whole idea of XP boxes is essentially to allow you to do this.

 

[Ramirez001]

That is generally the way it is done. As long as the assembly is not required to be listed, it is probably OK. No doubt people can come up with things that are not but the whole idea of XP boxes is essentially to allow you to do this.

Thank you for the reply Bob. In regards to your comment, "As long as the assembly is not required to be listed," when would one be required to have the assembly listed? If the concept is that you have an XP Box, and you can stuff it with your electrical components and call it done, then that should be enough right? I'm trying to think about it from the AHJ point of view... It is also my understanding that there are limitations as to how much you can actually put into an XP box for the concern of pressure piling. Your insight is greatly appreciated.

Cheers,

 

[Fulthrotl]

Thank you for the reply Bob. In regards to your comment, "As long as the assembly is not required to be listed," when would one be required to have the assembly listed? If the concept is that you have an XP Box, and you can stuff it with your electrical components and call it done, then that should be enough right? I'm trying to think about it from the AHJ point of view... It is also my understanding that there are limitations as to how much you can actually put into an XP box for the concern of pressure piling. Your insight is greatly appreciated.

Cheers,

should be enough that the enclosure, with appropriate seals, can contain
anything that will fit within it, that is of an electrical nature, that could
ignite the surrounding atmosphere.

now, if you are using it to store your supply of blasting caps and C4 plastque,
you'll need a separate listing for that, i'm sure.

 

[petersonra]

Thank you for the reply Bob. In regards to your comment, "As long as the assembly is not required to be listed," when would one be required to have the assembly listed? If the concept is that you have an XP Box, and you can stuff it with your electrical components and call it done, then that should be enough right? I'm trying to think about it from the AHJ point of view... It is also my understanding that there are limitations as to how much you can actually put into an XP box for the concern of pressure piling. Your insight is greatly appreciated.

Cheers,

For instance, there are some jurisdictions that require industrial control panels be listed. If the jurisdiction this equipment was being installed in required listing of industrial control panels, and it was an industrial control panel, than it would have to be listed to UL698A.

 

[Ramirez001]

Thanks guys.. Your insight is greatly appreciated.

 

[csc_wyo]

...stuffing it with my components and calling it done..."

My $0.02 is to be careful with that choice. I've seen people do this and forget all about the heat that the "stuffed components" create, cooking them until device failure. If installed in a cold or humid area, you need to watch out for condensation buildup as well. Simply stuffing components into a large XP/NEMA 7 type enclosure may temporarily solve your problem, but may create more long term and maintenance issues in the long run. Do your engineering in either case and evaluate the economics and risks associated with your decision making process.

 

[stgga]

Stuffing C1D1 cabinet

Stuffing C1D1 cabinet

For us to put the NRTL's bug on our cabinet we need to comply with the approved BOM. If a customer wants a device not in our listing then we don't put the bug on. The other factor we find that comes into play is what does the site insurer require? Great question by the way.

 

[stgga]

My $0.02 is to be careful with that choice. I've seen people do this and forget all about the heat that the "stuffed components" create, cooking them until device failure. If installed in a cold or humid area, you need to watch out for condensation buildup as well. Simply stuffing components into a large XP/NEMA 7 type enclosure may temporarily solve your problem, but may create more long term and maintenance issues in the long run. Do your engineering in either case and evaluate the economics and risks associated with your decision making process.

Great input!

 

[Kobe85]

For instance, there are some jurisdictions that require industrial control panels be listed. If the jurisdiction this equipment was being installed in required listing of industrial control panels, and it was an industrial control panel, than it would have to be listed to UL698A.

Is there a way to find out which jurisdictions require this? I've always had to have panels and boxes listed as industrial control panels (parts), but "assembly certified" (assembled by a certified body) listed is a different animal.

 

[petersonra]

Is there a way to find out which jurisdictions require this? I've always had to have panels and boxes listed as industrial control panels (parts), but "assembly certified" (assembled by a certified body) listed is a different animal.

as I understand it the whole state of washington is this way. as is LA and Chicago.

how well it is enforced is something else.