- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: open wiring
nhee,
There are two primary issues with cables terminating in enclosures required to be explosion proof in Division 2. One, that the explosion proof integrity of the enclosure is maintained and two, that the cable itself is not a migration path for ignitable gases through the seal. (See 501.5 FPN No. 1&2)
Note 501.5(B)(1) does NOT refer to 501.5(A)(1), but rather 501.5(A)(1)(1) because enclosures under 501.5(A)(1)(2) would not be required to be explosion proof whether they actually were or not. It is also important to recognize 501.5(C) is a requirement for all seals anyway. Finally we should note that 501.5(E) deals only the cables themselves and doesn?t deal with whether or not they are in raceways.
Personal aside: I don?t like the last sentence of the main text of 501.5(E); as a stand alone statement it implies that all multi-conductor cables are to treated as if they are terminated in Division 1, but I haven't figured out wording that I like any better, so I've avoided making any formal proposals.
Crouse-Hinds, lists their type TMCX series for terminating Type TC in XP enclosures using an epoxy sealant. Other manufactures are equally capable.
nhee,
There are two primary issues with cables terminating in enclosures required to be explosion proof in Division 2. One, that the explosion proof integrity of the enclosure is maintained and two, that the cable itself is not a migration path for ignitable gases through the seal. (See 501.5 FPN No. 1&2)
Note 501.5(B)(1) does NOT refer to 501.5(A)(1), but rather 501.5(A)(1)(1) because enclosures under 501.5(A)(1)(2) would not be required to be explosion proof whether they actually were or not. It is also important to recognize 501.5(C) is a requirement for all seals anyway. Finally we should note that 501.5(E) deals only the cables themselves and doesn?t deal with whether or not they are in raceways.
Personal aside: I don?t like the last sentence of the main text of 501.5(E); as a stand alone statement it implies that all multi-conductor cables are to treated as if they are terminated in Division 1, but I haven't figured out wording that I like any better, so I've avoided making any formal proposals.
Crouse-Hinds, lists their type TMCX series for terminating Type TC in XP enclosures using an epoxy sealant. Other manufactures are equally capable.