Recently witnessed an installation in which an intrinsically safe circuit from a tank radar gauge to indicator at ground level was installed in same RMC with non-intrisically safe power and comm circuits up the side of a storage tank (Class I, Div. 2). At first I thought this is not permissable per code, but then someone mentioned that if the raceway installation is per 501 for non-intrinsically safe circuits, then there is no code violation. This seems logical but is it correct?
Intrinsically safe circuits
- Thread starter bozo
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- Mission Viejo, CA
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- Professional Electrical Engineer
How would you interpret Section 504.30(A)(1)?
Thanks for the reply. I could understand this requirement if, at some point in the wiring system, the intrinsically safe circuit breaks away from the non-intrinsically safe circuit and at the same time transitions to a wiring method non-compliant with the area class. However, if the intrinsically safe circuit is entirely contained within a Class I Div. 2 wiring method, I don't comprehend why it would be a code violation. However, I certainly can't deny that 504.30(A)(1) appears to say it is.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
I suspect it wasn't installed per a control drawing as required by Section 504.10(A) either. "Other equipment" includes virtually everything else in the wiring method.
All that said, if it wasn't installed AS an intrinsically safe system, them you're probably right it didn't really matter - with regard to hazarous locations. However, much the same rules apply to Class 2 & 3 circuits installed under Article 725 regardless of the area classification. See Article 725 starting at 725.130 and following.
All that said, if it wasn't installed AS an intrinsically safe system, them you're probably right it didn't really matter - with regard to hazarous locations. However, much the same rules apply to Class 2 & 3 circuits installed under Article 725 regardless of the area classification. See Article 725 starting at 725.130 and following.
Thanks again. Appreciate the input. I will check out 725.
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