Hazardous Rated Rooms Use

[mooddoggy]

I have classified rooms at my facility, i.e., Cl I, Cl II, Div. 1 and 2. Question I have is if I want to perform an operation in a rated room that does not involve the use of the room rating, can I use general purpose portable equipment in the room? I cannot seem to find any reference to this situation in the NEC, NFPA or BOCA.

We rated the rooms as such because the permanent equipment in the rooms are rated hazardous duty. But at times we use the rooms for non hazardous work. Any codes that cover multiple use?

 

[rbalex]

First, welcome to the forums.

See Section 500.1. Locations are classified to select equipment, not because the equipment is suitable for a particular classified location. You have probably over-classified.

To answer your direct question, equipment must be suitable for each and every identified classification so general purpose equipment would not be suitable except a few possible Division 2 applications unless the work is done under a "hot work" permit.

For those of you that feel the urge to bring up intrinsically safe or nonincendive systems drop it now; the OP isn't familiar enough with the basics yet.

 

[mooddoggy]

Hazardouse Room Use

Hazardouse Room Use

Thanks for responding. Still confused. Is it possible to run a non hazardous operation in a classified room using non hazardous equipment. For example, I have hazardous receptacles in the room. I want to run a cleaning skid in the room which just uses water. There are no vapors, no dust in the room because its a batch operation that is normally performed in the room, but room is not in use.

I guess what I am saying is that if a rated room is not in use and there are no conditions present that cause the room to be rated, can the room be used for non hazardous operations. For example, the rated room has 2 mixing tanks for liquids prep and as such room is rated for CL I, Div. 1. But most times the room is not in use and hence no chemicals are in the room. There is nothing in the room that would cause it to be rated. Can I perform non hazardous (water ) operations in the room using non rated portable skidded equipment that I bring into the room. THe portabe equipment is not rated.

Does that make sense.

 

[rbalex]

... Is it possible to run a non hazardous operation in a classified room using non hazardous equipment...
... Does that make sense.

I understood what you wanted to do in the original post (OP); it's a common question. While it's possible, it's just not immediately Code compliant. Once a location is classified, the electrical equipment used in the room must be suitable for the identified classification(s).

Let's get a few, but not necessarily all, basics out of the way:

1. Electrical equipment is selected for the location's electrical area classification [Section 500.1], NOT the other way around.
2. The electrical equipment must be suitable [500.8(A)] for the location's electrical area classification(s) [500.8(B)]
3. The electrical area classification must be properly documented [500.4(A)]
4. The electrical area classification cannot usually be determined directly from the NEC unless the installation is consistent with Articles 511 to 516; otherwise,
5. the electrical area classification should be determined from one of the reference standards in Section 500.4(B) Fine Print/Informational Notes.

The only way for the temporary activities you described to be NEC compliant is to reclassify and redocument the location. The most common way is by issuance of a temporary "hot work" permit.

 

[mooddoggy]

hazardous area use

hazardous area use

Thank you for your documented response. I understand the use of the "Hot Permit". That is an appropriate path to follow.

Thank you again.

Most informative