Tray Cable terminating in Class I Div 2 Area

[jrc0109]

NEC Article 501.15(E) Cable Seals, Class I Division 2
Can anyone suggest a good reference that explains when and where seals in Tray Cable (Type TC) are needed?

For example: Where is the "point of entrance" - when the cable enters a Class I Div 2 Area or where it enters the Explosionproof enclosure in the Class I Div 2 Area?

Thanks;
john

 

[rbalex]

Re: Tray Cable terminating in Class I Div 2 Area

From the UL Online Guide Information for Power and Control Tray Cable (Category Code: QPOR)

Regarding cable seals outlined in Article 501 of the NEC, Type TC cable has a sheath which is considered to be gas/vapor tight but the cable has not been investigated for transmission of gases or vapors through its core.

The fact that ??the cable has not been investigated for transmission of gases or vapors through its core? is largely irrelevant.

What is relevant is Type TC cables definitely fall under Section 501.15(E)(3). In that case, Type TC cables are not required to be sealed unless they are ??entering enclosures that are required to be explosionproof?? per the back reference to 501.15(E)(1) or ??unless the cable is attached to process equipment or devices that may cause a pressure in excess of 1500 pascals (6 in. of water) to be exerted at a cable end?? per the rest of 501.15(E)(3).

In either case the seal, if necessary at all, is at the cable termination only.

 

[jrc0109]

Re: Tray Cable terminating in Class I Div 2 Area

Thanks Bob.
So does that mean inside a Class I Div 2 area, there can be enclosures that are not explosion proof and if a TC cable is terminated in it, it does not have to be sealed?
Does the cable have to be sealed at the point it enters the Class I Div 2 area?

Thanks,
John

 

[rbalex]

Re: Tray Cable terminating in Class I Div 2 Area

So does that mean inside a Class I Div 2 area, there can be enclosures that are not explosion proof - yes

and if a TC cable is terminated in it, it does not have to be sealed? - yes

Does the cable have to be sealed at the point it enters the Class I Div 2 area? - no