502.10 NEC2002 Utilization equipment

[JoeSparky1]

Would proximity switches, limit switches, or encoders be considered utilization equipment?

The devices listed above are in a Class2 Div. 1 area inside of a process container. Do they need to be rated for that environment? (see 502.1) :-? The enclosure where the wires from these device terminate is in an unclassified area. Do I need to use a specific type of box?

thanks,

 

[barbeer]

I would consider them controls and not equipment, and IMHO they would need to meet classification criteria.

 

[rbalex]

Utilization Equipment is a defined term in Article 100. The switches are not utilization equipment, the encoders may be.

In either case, if they in an overall enclosure suitable for Class II, Division 1 and the appropriate Group, they should be acceptable. In Division 1, that would normally require dust-ignition proof (NEMA 9) See [2002 NEC, Section 502.6(A)(1)] They would not normally require individual certifications.

 

[JoeSparky1]

The switches and encoders are not in specific enclosures. I was just trying to indicate that they were located within an "area" that is Class2 Div.1 (think of a grain bin)-the devices are inside and the wires come out of the bin and are landed in a box that is outside the bin.

When I read [2002 NEC, Section 502.6(A)(1)] I would say that anything in the hazardous area needs to be #1 in a rated box, or #2 rated for use in that specific area.

 

[rbalex]

...
When I read [2002 NEC, Section 502.6(A)(1)] I would say that anything in the hazardous area needs to be #1 in a rated box, or #2 rated for use in that specific area.

I would concur with your analysis.