MC Cable gland in Class I Div 2 location

[nhee2]

We are specifying MC cable in a Class I, Div 2 location. There are no explosion-proof devices - all cable terminations are into general purpose boxes/fittings.

My understanding is/was we can use standard cable glands such as Crouse-Hinds TMC style, but these are not marked as listed for Class I, Div 2 locations, where others do have that listing.

Is it correct that the TMC style cable gland is acceptable in Class I, Div 2, provided we are not going into explosion-proof equipment? Additionally, none of the cables are crossing a classification boundary - no boundary seals in this application.

 

[rbalex]

...
Is it correct that the TMC style cable gland is acceptable in Class I, Div 2, provided we are not going into explosion-proof equipment? Additionally, none of the cables are crossing a classification boundary - no boundary seals in this application.

In my opinion, this would be an application of Sections 501.15(E)(1) and (3) and Section 500.8(C)(6)(a); i.e., TMC glands are acceptable and no boundary seals are required in this particular application, and no Class I, Division 2 marking is required.

 

[nhee2]

In my opinion, this would be an application of Sections 501.15(E)(1) and (3) and Section 500.8(C)(6)(a); i.e., TMC glands are acceptable and no boundary seals are required in this particular application, and no Class I, Division 2 marking is required.

Thanks, that is what I also think.

The literature at https://www.prysmiangroup.com/sites/default/files/atoms/files/Bicon_Glands_UL_CSA_ US_Standards.pdf shows their 424CU glands as 'explosion-proof' for Cl I, Div 2 locations, which confused me. Normally explosion-proof components are good for both Div 1 and Div 2. Which led me to question whether a Div 2 listing was required. I assume the reason this explosion-proof component is limited to Div 2, is because MC cable is only allowed in Div 2, and not Div 1?

 

[rbalex]

Thanks, that is what I also think.

The literature at https://www.prysmiangroup.com/sites/default/files/atoms/files/Bicon_Glands_UL_CSA_ US_Standards.pdf shows their 424CU glands as 'explosion-proof' for Cl I, Div 2 locations, which confused me. Normally explosion-proof components are good for both Div 1 and Div 2. Which led me to question whether a Div 2 listing was required. I assume the reason this explosion-proof component is limited to Div 2, is because MC cable is only allowed in Div 2, and not Div 1?

As I have said before, I don't rely on manufacture's literature too often - especially sales versus technical literature.

 

[rbalex]

While I'm thinking about it, see Section 500.8 (C)(2 ) with respect to Division 2 marking.

 

[nhee2]

While I'm thinking about it, see Section 500.8 (C)(2 ) with respect to Division 2 marking.

The glands I referenced were marked (or advertised) as Explosion-proof. Just not clear to me how something is 'explosion-proof' in a Div 2 environment, but not explosion-proof in a Div 1 environment.

Regardless, I think your earlier reference to 500.8(C)(6)(a) is what applies to my application, I think the TMC glands are ok.

 

[rbalex]

Brits think NEC explosionproof and IEC flameproof are conceptually the same. (Most Yanks do too) They are similar but not identical. IEC glands suitable for Zones will often be marked as flameproof. Prysmian appears to have extended the concept to explosionproof markings in Divisions.

While it is moot since you aren't crossing any boundaries, I note the 424CU glands are for interlocked armor MC. Technically, that shifts to a Section 501.15(E)(4) application. UL only recognizes corrugated and smooth sheath constructions as being vapor-tight - even with an outer jacket.