Hazardous location?

[steve66]

I am designing the electrical for two toilet rooms. There is a room for a enclosed sewage tank, and pump to pump the sewage up and across a factory to an existing sewage line. The room has an exhaust fan that runs constantly. Is this room a Class 1, Division 2 location?

The sealed tank could devolop a leak, and the exhaust fan could quit. This could allow explosive gas to build up, so I would think it would be a hazardous location.

Steve

 

[tom baker]

Re: Hazardous location?

NFPA 820 is a standard that you should take a look at, it deals with WWTP and sewage pumping stations.
Also take a look at NEC section 500.4 (A) documentation.
I don't think your application is hazardous, as under normal conditions it would not be. You could always interlock the exhaust fan to the pump power.

 

[steve66]

Re: Hazardous location?

Thanks for the reply Tom. I looked at NFPA 820 and decided it doesn't apply. (I think this would be called a "Pressure Sewer System", and 820 wouldn't apply per 1-1.1.3).

I don't think the location is hazardous anymore either. Instead of interlocking the pump and fan, I think I may provide a flashing light alarm for both high water or exhaust fan not working.

Steve

 

[tom baker]

Re: Hazardous location?

Having NFPA 820 is a great start! Its not a well know standard. Here is what I know: sewage wet wells are Class I Div 1. Your little pumping pit would be the same.If you design from there you should be OK.