Cable Trays in Class 1 Div 2 area

[richanton]

I'm having a heated discussion on this. The question is if I am using cable tray, and Type TC cable, is there some special sealing required at the boundary between the Class 1 Div 2 area and the non-hazardous area. My take is "No" if it's ladder tray, and I don't know what happens if its solid tray. The only sealing is at the enclosure the cable terminates at. Any opinions or links to discussion areas.

 

[Senselessticker]

Take a look at NEC 501.15 and be prepared to mull over it for awhile. There are many factors at play depending on your specific situation.

 

[rbalex]

Section 501.15 is the right general reference, but 501.15(E)(1) and (3) is what you want to look at specifically.

A couple of things to note:

1. Cable Tray is not a raceway per the NEC (it's a support system).

2. UL's standard on Type TC says it has a "gas/vaportight continuous sheath," but is silent on whether it can transmit gases through the core. Assume it can. This is largely irrelevant to the OP, since a boundary seal isn’t mentioned in Subsection 501.15(E)(3).

3. In fact the only mention of a boundary in Subsection 501.15(E)(4) which doesn’t apply to Type TC.

 

[richanton]

Thanks. You have basically agreed with my interpretation and provided the missing link I did not have that UL 1277 says Type TC cable is gas/vaportight.

 

[suriae]

The issue is about fire class and additionally, as you mentioned, between hazardous and non-hazardous area. The requirement is "penetration MUST be sealed according to the intergrity of the boundary no matter ladder or solid tray is used".Generallry cable trays are terminated 100-300mm from the penetration ends depending on the size or group of cables.
There are some method in sealing of penetration;
a)Using a water base hardening compound, ex APEX
b)Using an MCT
c)Using an inert-heat activated sealant, ex RISE System manufactured by Belle Corp.

 

[Inspector4EI]

No need to seal.