Class 1 div 1 low voltage

[bkamp77]

This might be a stupid question but do I have to use a seal off on the data conduit when wiring a gas pump and card reader?
Thanks

 

[j-dub]

Yes, table 501.1 in the N.E.C. also -not sure of the article but it states that the requirements are not contingent on the voltage.

 

[rbalex]

Yes, table 501.1 in the N.E.C. also -not sure of the article but it states that the requirements are not contingent on the voltage.

Table 501.1 does not exist in the NEC. There is such a Table in the NEC Handbook and it is a fair summary of requirements. However, it is important to know the Handbook?s commentary is not ?officially? authoritative. See the 2nd paragraph in the Section ?Notice Concerning Code Interpretations? on the front inside flyleaf.

The Scope statement in Section 500.1 notes that Articles 500 through 504 apply to all voltages; however, those Articles occasionally recognize certain conditions that may alter ?general? requirements; this is especially true with low power (not voltage) applications. There are also some special provisions for shielded instrumentation type cables and other cable constructions.

Without specific knowledge of the entire installation, it is virtually impossible to make an absolute statement about the sealing requirements. Seals are probably necessary, but even that isn?t the whole story.

 

[erickench]

NEC 501(A)(4) state's that boundary seals are required in each conduit run that leaves a Class I Division I location. It's permitted on either side of the boundary. So maybe you do need them.

 

[crossman gary]

501.15 pretty much gives the answer. And FPN 1 in that section tells why. Voltage doesn't matter. Even a spare conduit for future use with nothing in it would need to be sealed.

 

[weressl]

Table 501.1 does not exist in the NEC. There is such a Table in the NEC Handbook and it is a fair summary of requirements. However, it is important to know the Handbook?s commentary is not ?officially? authoritative. See the 2nd paragraph in the Section ?Notice Concerning Code Interpretations? on the front inside flyleaf.

The Scope statement in Section 500.1 notes that Articles 500 through 504 apply to all voltages; however, those Articles occasionally recognize certain conditions that may alter ?general? requirements; this is especially true with low power (not voltage) applications. There are also some special provisions for shielded instrumentation type cables and other cable constructions.

Without specific knowledge of the entire installation, it is virtually impossible to make an absolute statement about the sealing requirements. Seals are probably necessary, but even that isn?t the whole story.

Bob,

If we are to pass an IS cable through a solid concrete wall that separates Cl.I, Div.1 environment from a nonclassified area, would it need to have and XP seal, or a sealing method equivalent to the solid wall be sufficient?

 

[rbalex]

Bob,

If we are to pass an IS cable through a solid concrete wall that separates Cl.I, Div.1 environment from a nonclassified area, would it need to have and XP seal, or a sealing method equivalent to the solid wall be sufficient?

In that scenariao, Section 504.70 would apply directly; a boundary seal is required but it is not required to be explosionproof.

 

[weressl]

In that scenariao, Section 504.70 would apply directly; a boundary seal is required but it is not required to be explosionproof.

So where would one find such animal that meets the criteria?

<<but shall be identified for the purpose of minimizing passage of gases, vapors, or dusts under normal operating conditions>>

...and why don't we just have and XP and a pressure seal category, defined and dealt with them separately as applicable?

Thanks for the discourse.:smile:​

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[rbalex]

In this case, identified is the key term. See Section 500.8(A)(3)[2008 NEC] with CMP14's view.

 

[weressl]

In this case, identified is the key term. See Section 500.8(A)(3)[2008 NEC] with CMP14's view.

I understand.

The other part of my question was: is there such fitting. (Identified for the prevention of passing gas.) I never seen one.

 

[rbalex]

The next term to note is minimize, not necessarily prevent.

Now remember, I'm not too keen on nonexplosionproof seals in the first place; but several materials, such as duct seal, have been suggested. The idea being a product that tends to be stable in a fairly broad range of enviornments and generally avoids shrinking. Several of the major Hazloc manufacturers have toyed with creating a listable material; but, to my knowledge, no NRTL has created a test standard.

 

[weressl]

The next term to note is minimize, not necessarily prevent.

Now remember, I'm not too keen on nonexplosionproof seals in the first place; but several materials, such as duct seal, have been suggested. The idea being a product that tends to be stable in a fairly broad range of enviornments and generally avoids shrinking. Several of the major Hazloc manufacturers have toyed with creating a listable material; but, to my knowledge, no NRTL has created a test standard.

I know and as an engineer I hate unquantified terms, such as 'minimize'. Gimme a number......

I think duct seal is unlike duct tape. It is installation dependent, an ad-hoc application and the outcome is highly unreliable. When it comes to Hazloc installation it is just too loosey-goosey for my taste. So if there is no such product, then there is no way to know in advance wheather your installation will be agreable to the AHJ? In otherwords, another loophole in the NEC?

 

[rbalex]

I know and as an engineer I hate unquantified terms, such as 'minimize'. Gimme a number......
...

The number does exist - it's just in the wrong place at the moment. Its in 501.15(E)(2). Section 501.15 FPN No. 1 refers to it while recognizing even explosionproof seals can't actually prevent migration.

 

[weressl]

The number does exist - it's just in the wrong place at the moment. Its in 501.15(E)(2). Section 501.15 FPN No. 1 refers to it while recognizing even explosionproof seals can't actually prevent migration.

Yep, convoluted and indirect, or is this just me?:roll:

 

[rbalex]

No - it ain't just you; it's just how the Code "evolves." This little discussion did give me a Proposal for the 2014 NEC though. I tried to see if I could slip it in during the 2011 Comment stage but no such luck; I couldn't find an active Proposal that was inclusive enough.