temperature switch

[don_resqcapt19]

I have a temperature switch with 1/2" threaded conduit and 8" leads on one end. The other end of the switch has pipe thread and will be inserted into the process piping. The process fluid is water. The location where the switch will be installed is a Class I, Divison 2, Group D location.
This switch is not maked as suitable for the classification. The manufacturer says that if I install a conduit body suitable for the classification, make my splices in the conduit body and place a seal fitting on the other opening of the conduit body that I can use the switch in the classified area. Is the manufacturer correct? I believe that the switch itself must be marked as suitable for the classification.
Don

 

[petersonra]

If the switch itself is hermetically sealed, or is electronic (as opposed to a hard switch), it should be acceptable.

I am not sure it has to be marked.

 

[don_resqcapt19]

Bob,
It is not a hermetically sealed switch and is not electronic. The marking is my real question. 501.105(B)(1) says:

(1) Contacts Switches, circuit breakers, and make-and-break contacts of pushbuttons, relays, alarm bells, and horns shall have enclosures identified for Class I, Division 1 locations in accordance with 501.105(A).

Does this apply to the switch device itself or the enclosure that the manufacturer is telling me to add in the field?
Don

 

[rbalex]

Don,

Under one of the 501.105 (B)(1) Exceptions 1 to 3, no specific marking is required; otherwise, it must be listed for Division 2 per Exception 4. It almost sounds like the manufacturer is misapplying 501.15(F)(3).

 

[don_resqcapt19]

Bob,
The device in question does not meet any of the exceptions in that code section. There is no real enclosure on the switch, just two wires comming out of a 1/2" male thread. The manufacturer's position is that if I add an explosionproof conduit enclosure (that is marked for the classification) and a seal, we are in compliance with the NEC. I don't really agree and was just looking for some back-up. Also I doubt that they are thinking of a nonincendive circuit as the switch contacts are rated at 10 amps at 120 volts.
Thanks.
Don

 

[celtic]

This is a bit out my area, but here's my convoluted thoughts....

In a gas/service station, are there ANY electrical devices below the "plane" ....514.19 ....say the station has oil change services and there is a pit, the man brings a portable light into that area - how is that affected by the location? (Is the light explosion proof? I don't know, I change my own oil)