Class I, Division 2 wiring

[sgunsel]

501.10(B)(2)(5) allows flexible cord (e.g. SOW) with an EGC to be installed with a listed bushed fitting. Is a seal required where entering an explosion proof enclosure? 501.15(B)(1) seems to require a seal. If sealing is also required, is the jacket stripped from the wires in the seal? Thanks.

 

[petersonra]

501.10(B)(2)(5) allows flexible cord (e.g. SOW) with an EGC to be installed with a listed bushed fitting. Is a seal required where entering an explosion proof enclosure? 501.15(B)(1) seems to require a seal. If sealing is also required, is the jacket stripped from the wires in the seal? Thanks.

Is SOW actually accepted for this use?

501.15(B)(1) Entering Enclosures. For connections to enclosures
that are required to be explosionproof,

IMO, if the enclosure is not required to be XP, you don't need a seal.

If the enclosure is required to be XP, refer to 501.15(A)(1).

Chances are no one would have put an XP box in a div 2 area unless it was required to be XP, but you never know.

 

[rbalex]

Good question, good insights Bob

Even without a direct cross reference for Division 2, use of Flexible cords are still subject to 501.140. (Looks like I got another Proposal to make) SOW is indeed acceptable. See Table 400.4.

Flexible Cords are still "cables" and subject to 501.15 (D) and (E) not 501.15(B)

 

[sgunsel]

501.15(A)(1) is Div 1. This is a Div 2 area. The enclosure contains contactors, so is required to be explosionproof, 501.105(B)(1). 501.140(B) requires "suitable seals" but the exception says "Seals shall not be required as provided in 501.10(B) and 501.105(B)(6) (listed fittings LFMC), listed bushed fitting (flexible cord).

What is a suitable seal?

 

[rbalex]

You still appear to be applying conduit rules to a cable installation. They do apply ocassionally, but start with Section 501.15(E) for Division 2, cable installations. Section 501.15(E)(1) does cross reference to 501.15(B)(1) which further cross references to 501.15(A)(1)(1) and (A)(3).

Per your current description, you will need an explosionproof seal. You may as well assume that SOW is a "[m]ulticonductor cable with a gas/vaportight continuous sheath capable of transmitting gases or vapors through the cable core..." since no manufacturer will guarantee it won't "...transmit gases or vapors through the cable core."

That said, the SOW "... shall be sealed in a listed fitting in the Division 2 location after removing the jacket and any other coverings so that the sealing compound surrounds each individual insulated conductor in such a manner as to minimize the passage of gases and vapors.

 

[sgunsel]

rbalex,

Thanks. I do get confused at times.

 

[rbalex]

rbalex,

Thanks. I do get confused at times.

YOU'RE confused? One of the reasons my post-count is low compared to most of the other moderator's is my need to re-read almost all of Arts 500-516 to confirm I haven't misread something.