Class 1 / Div 1 Non-rated Tools

[wolff162]

We have a paint cell (50' X 50' X 50') that is a Class 1 Division 1 space. My rule to building operations is that once a Class 1 / Div 1, always a Class 1 / Div 1 space. That is, the NEC does not make provisions that the classification is contingent on the use at that time.

Just because you are not painting at this moment does not mean that you drag a bunch of drop lights plugged into extensions cords into the cell. Whether you are painting now or not, the classification of the area remains the same.

Am I on track with this so far? If any of you think I am being overly restrictive, please let me know.

Now they have a need to do some work in the cell and are asking to bring in a variety of electrical equipment that is not rated for use in a Class 1 / Div 1 space. I am telling them that they can not just go and do this - there is no provision in the NEC to suddenly decide the area is no longer classified for the next 3 days, but it is again on day 4.

I did say that with the full blessing of Safety, the company Fire Marshal, the municipal Fire Chief, and a licensed electrican, along with appropriate measures such as cleaning the cell, constant ventilation, and constant LEL monitoring, that it could possibly be done?

What are your collective thoughts on this? Any one else ever run into this, or am I just being paranoid?

Thanks

 

[rbalex]

Re: Class 1 / Div 1 Non-rated Tools

Your basic approach is reasonable.

In theory a location can change classification from day to day - even moment to moment. However, it must be "properly documented" in each case in order top do so. See [2002] 500.4(A).

In your case, a "hot work" permit, signed by appropriate management, safety, etc is an essential part of the "proper documentation." For example, this is how necessary welding activities are commonly conducted in hazardous locations.

 

[petersonra]

Re: Class 1 / Div 1 Non-rated Tools

Bob has the right idea here. You can certainly declare an area nonhazardous for a specific period of time under specific circumstances. This is very common.

It's a matter of coming up with a safe way to implement it that is often the issue.

I don't see there is any need for any specific people to be involved (such as an electrician or a fire marshall). Only that you have a safe and documented procedure.

 

[rbalex]

Re: Class 1 / Div 1 Non-rated Tools

"Hot work" is a general term under FedOSHA that covers several issues. If your State has its own OSHA, its rules a probably similar.

Typically, some form of documented responsible management approval is necessary. They may get as much input as they need from others as they feel necessary to make the decision.

 

[petersonra]

Re: Class 1 / Div 1 Non-rated Tools

Yep. And many plants have interesting ideas about what consitututes "hot work".

I was in a plant one time where they considered use of anything with a battery in it to require a hot work permit. Just to bring my computer into the area (because it had a battery in it)required a hot work permit signed by the plant manager (who was the ONLY person who could sign hot work permits). No hot work was done if he was not in the plant (although once he was out of town and they got him to sign one via fax).

These permits were good for an entire week and also covered my watch (also had a battery in it) but not cell phones or pagers.