Unnecessary Intrinsically Safe (IS) Systems - Comply w/ 504.30?

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lakee911

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Columbus, OH
Hi All,

I have a situation where we planned on using general purpose NEMA 4X control stations in a Class I, Div. 1 area so we made them intrinsically safe. The Contractor mistakenly supplied explosion proof (XP) control stations and pushbuttons. They also accidentally combined the IS wiring with non-intrinsically safe.

Given that this is all now XP, I see this as being safe, but it is a violation of NEC Article 504.30. Is it permissible to allow this to slide, or should I have them make revisions and remove the components that make it IS?

Thx,
Jason
 
Both petersonra and Smart $ make good points; however, without speculating beyond the OP and its title there's no reason to do anything. Intrinsically Safe systems are permitted not required.

IMO, if the only purpose for IS were to use NEMA 4X pushbuttons, it was a questionable design to start with.
 
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Smart $ said:
True... but once you have an IS system, 504.30 requires separation from any non-IS system.
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NOT true. You are permitted to use any ordinary location wiring method if it is IS. However,, if the wiring is otherwise suitable for Class I, Division 1 there is no requirement to use the IS features.
 
rbalex said:
NOT true. You are permitted to use any ordinary location wiring method if it is IS. However,, if the wiring is otherwise suitable for Class I, Division 1 there is no requirement to use the IS features.
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Simply stated, you cannot mix IS with non-IS.

If you remove the existing IS-barriers, and the IS-circuits were wired using a non-CID1 compliant wiring method, you have another problem.
 
Smart $ said:
Simply stated, you cannot mix IS with non-IS.

If you remove the existing IS-barriers, and the IS-circuits were wired using a non-CID1 compliant wiring method, you have another problem.
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The OP stated they were mixed in with the non-is circuits. I took that to mean they ran them in the same conduit.

They might be class 1 or 2 circuits if you take out the IS barriers.

it is really hard to tell without a lot more information.
 
Smart $ said:
Simply stated, you cannot mix IS with non-IS.

If you remove the existing IS-barriers, and the IS-circuits were wired using a non-CID1 compliant wiring method, you have another problem.
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Simply stated, "Who says?" You are still speculating.
 
petersonra said:
The OP stated they were mixed in with the non-is circuits. I took that to mean they ran them in the same conduit.

They might be class 1 or 2 circuits if you take out the IS barriers.

it is really hard to tell without a lot more information.
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So? The barriers don't make them IS or even Art. 725. Until the OP actually addresses the questions you're still speculating - stop it ;)
 
rbalex said:
So? The barriers don't make them IS or even Art. 725. Until the OP actually addresses the questions you're still speculating - stop it ;)
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Our questions are in the form of speculation (including yours, so to speak). Otherwise, I answered the only question, which was posed in the OP.

The underlying question is what revisions are necessary to make the installation compliant? ...and I am assuming with the condition: other than replacing the XP stations and buttons. To get there, details of this non-compliant installation must be divulged.
 
Smart $ said:
Our questions are in the form of speculation (including yours, so to speak). Otherwise, I answered the only question, which was posed in the OP.

The underlying question is what revisions are necessary to make the installation compliant? ...and I am assuming with the condition: other than replacing the XP stations and buttons. To get there, details of this non-compliant installation must be divulged.
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I also answered the OP question asked: nothing is necessary based simply on the OP and the thread's title - no speculation was necessary at all.

The OP's opinion was IS wasn't necessary. I acknowledged you and petersonra raised reasonable questions. However, simply using IS rated equipment doesn't make it an IS system or necessarily subject to Art. 725 either.
 
rbalex said:
I also answered the OP question asked: nothing is necessary based simply on the OP and the thread's title - no speculation was necessary at all.

The OP's opinion was IS wasn't necessary. I acknowledged you and petersonra raised reasonable questions. However, simply using IS rated equipment doesn't make it an IS system or necessarily subject to Art. 725 either.
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Taking your "speculation" :D into consideration changes the root question to: is the installation non-compliant? Still need details to make that determination.
 
Smart $ said:
petersonra said:
At worst they take out the IS barriers.
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I'd say that'd be the easiest... not at worst. However, doing so may create another problem if non-CID1 wiring method was used for the IS circuits.
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That's what I was thinking about doing, but I'm not questioning whether it's necessary based on responses in this thread. No non-CID1 wiring methods were used. If the barriers were removed, it would be code compliant.

petersonra said:
The OP stated they were mixed in with the non-is circuits. I took that to mean they ran them in the same conduit.
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That is correct.

petersonra said:
They might be class 1 or 2 circuits if you take out the IS barriers.

it is really hard to tell without a lot more information.
Click to expand...

I believe these would be a Class 1 circuit without the barriers. All wire would be of the appropriate voltage rating and it's all installed in conduit.
 
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