In-line or block type terminal for class 1 division 2 area.

[bluesmoke...oops]

I have a client that wants an in-line terminal in a condulet type fitting downstream of the seal for ease of future device replacement. I have yet to find either a small terminal block (6 feed through spaces) or an inline method of providing the desired break for each conductor. The method needs to be rated for a class 1 division 2 area, and fairly small. Any help would be appreciated.

 

[petersonra]

I have never really thought about this all that much, but do terminals have to be identified for C1D2?

 

[bluesmoke...oops]

Not entirely sure what the nec says on it, I'm fairly new to the realm of 501, but at the least the client is requesting class 1 div 2 listed or listed as non-incendive. The design is trying to avoid the explosion proof enclosures.

 

[rbalex]

It sounds like your client may have an IEC background or is influenced by someone who has one. Under "classic" IEC Zone concepts, terminals are considered "arc-making" and are required to be certified "EX e." Essentially, this means the terminal is "self-locking," "pullout resistent" and "vibration proof."

NEC does not require any of those features in Class I, Division 2 and enclosures for terminals only are not required to be explosionproof.

 

[bluesmoke...oops]

It's an NQA-1 level project, so the client is being especially strict in their requirements.

 

[rbalex]

You won't find terminals, specifically listed as nonincindive nor for Class I, Division 2.

 

[rbalex]

I should add you won't find a terminal marked for Class I, Division 1 either.

Your best bet is to get one marked "AEx e" which will have the IEC features I mentioned and is suitable for Division 2. See Section 501.5. Some of the "miniature" blocks may suit you, but be careful of the volume.

 

[kwired]

Hazardous location or not, the conduit body would still need enough volume to meet requirements of 314.16(C).

 

[bluesmoke...oops]

Yeah I'm leaning more and more towards politely telling the client that isn't going to be designed that way.

 

[rbalex]

Yeah I'm leaning more and more towards politely telling the client that isn't going to be designed that way.

In that case, I have another suggestion. It is my opinion that properly installed "twist type" connectors, specifically with spring steel wire with a square (not round) cross-section (3M), probably meets most of the "AEx e" necessary requirements. They aren't (and will never be) listed for it though because the IEC standard 60079-7 wants terminal blocks and CENELEC (EU IEC Reps) wants the trade barrier. They are however suitable for US domestic Division 2, but not specifically listed. I specify them routinely, although they aren’t an absolute NEC requirement either. I also specify “AEx E” terminal blocks in Division 2, when I believe it’s appropriate

 

[weressl]

I also specify ?AEx E? terminal blocks in Division 2, when I believe it?s appropriate

Bob, I don't want to hijack the thread, but this begs the question: when would you find it 'appropriate'?

 

[rbalex]

Bob, I don't want to hijack the thread, but this begs the question: when would you find it 'appropriate'?

Usually high-amplitude, low frequency vibration locations; typically large, low speed reciprocal compressors. It is belt & suspenders, but it?s usually a relatively low cost and I sleep a bit better.

 

[Smart $]

I have a client that wants an in-line terminal in a condulet type fitting downstream of the seal for ease of future device replacement. I have yet to find either a small terminal block (6 feed through spaces) or an inline method of providing the desired break for each conductor. The method needs to be rated for a class 1 division 2 area, and fairly small. Any help would be appreciated.

In the past year I've work at a couple nuclear power plants. I've not been involved with part specifications or NQA-1. I can tell you in my limited experience what was used for a couple applications like you describe, but in areas that likely would not be NEC classified hazardous.

One method used was knife disconnect splice terminals. Here's a link to PIDG example http://www.te.com/catalog/pn/en/8-35762-2

The blade area of the splice was backwrapped with electrical tape, then raychem'd (thick-wall heat shrink with sealant adhesive on the inside) to a specified minimum distance beyond the terminals in both directions.

Another method was male-female connectors the name of which I cannot recall at present. The insulating mating boots were pliable like silicon-rubber. If I recall the name I'll post again.

 

[MichaelGP3]

.....
Another method was male-female connectors the name of which I cannot recall at present. The insulating mating boots were pliable like silicon-rubber. If I recall the name I'll post again.

Do you mean bullet connectors?

 

[Smart $]

Do you mean bullet connectors?

Similar connection concept, pin and sleeve, but appears machined rather than stamped and rolled like your typical bullet term's.