Type Z purged enclosure -> Cable in C1D2 -> solenoid valve - Sealing required?

[DanielW]

Hi,

I want to run a cable (I assume we'll be using some multiconductor cord for extra hard usage) from a type z purged enclosure to a solenoid valve listed for GP in C1D2. The surrounding is a C1D2 area.

Since the valve's enclosure is not required to be explosionproof and the fact that it comes with a listed cable plug, no sealing fitting is required on this side, right?

And also: per NEC 501.15(E)(1) Excp. 1 and NFPA 496 4.3.4 I don't need sealing fittings for cables leaving the enclosure. Just ordenary cable bushings to maintain the pressure inside the enclosure. Correct?

Now NEC 501.10(B)(2)(5) asks for listed fittings for extra hard usage cords. Do I need listed fittings under these conditions?

Daniel

 

[DanielW]

Actually we are planning to use UL-listed Lapp SKINTOP cable glands for the enclosure. Will they do the job?

 

[rbalex]

Your analysis is pretty good except for why you are using extra hard usage cord. It should only be used "[w]here provision must be made for limited flexibility...". Depending on the actual application, I would probably consider one of the cable types listed in 501.10(B)(1).

The primary purpose of the "listed fittings" in either 501.10(B)(1) or (2) is to relieve stress on the cables and their terminations; they have little use as a sealing means unless they are specifically listed for it. Fortunately, you don't need them as seals.

FWIW, NFPA 496 is a "Recommended Practice", not a "Code" or "Standard" in NFPA's terminology.

 

[DanielW]

Thanks for your reply. I'm happy to hear that my Interpretation was right.
Ok, regarding the cable I we are still in discussion what type of cable to use (maybe MV or TC type).

Daniel

 

[rbalex]

Thanks for your reply. I'm happy to hear that my Interpretation was right.
Ok, regarding the cable I we are still in discussion what type of cable to use (maybe MV or TC type).

Daniel

I believe you mean Type MC rather than MV. Either MC or TC is fine. You may find Types PLTC or ITC even more suitable. There are many acceptable cable options listed in Section 501.10(B).