Cable jacket

[Bulawayo]

A remote I/O termination cabinet located in a Class 1 Div 2 location. The cabinet has a Z purge(N2) on it with conduit seal at the termination cabinet. My question is:

Would the outer jacket of a twisted pair shield instrument cable be required to be removed to pour the seal?

 

[rbalex]

Re: Cable jacket

No

Since it is purged, technically the cable does not need to be sealed at all. (Although its a good idea and helps inprove the Z Purge integrity).

 

[jbwhite]

Re: Cable jacket

i have the same question as the OP but, what if i do not have a purge system. does the outer covering have to be stripped off?

also what would change if i use an intrinsic safe barrier at the panel, located outside the classified location. do i even need sealoff?

 

[rbalex]

Re: Cable jacket

Originally posted by jbwhite:
i have the same question as the OP but, what if i do not have a purge system. does the outer covering have to be stripped off?

also what would change if i use an intrinsic safe barrier at the panel, located outside the classified location. do i even need sealoff?

As you might expect, that may change the situation considerably.

First, you need to determine if the enclosure needs to be explosionproof. See [2005] 501.10(B)(4).

If yes, then a seal is needed. It may serve both the conduit and the cable. The outer-jacket of the cable must be removed. See 501.15(B)(1) with its back reference to 501.15(A)(1). However, the shield material itself does not need to be removed, nor the individual conductors separated. See 501.15(E)(1) Exception 2.

If no, then no seal is required. See the main rule 501.15(E)(1). This is actually why no seal was needed in the OP since the enclosure of a properly purged system does not need to be explosionproof.

Intrinsically safe systems have their own set of rules. If a seal is necessary, it is not required to be explosionproof. See 504.70.