Fuel Gas in unclassified location

[waltbikerun]

I have a Microturbine generator 30KW that requires 55 Psig of Natural Gas (fuel gas) and is inside a general porpoise building.
Question: Does this Mircoturbine inside the building makes the inside the building a Class 1 Div. 2 location? Or is there any exception on the NEC code book that says that equipment that requires low pressure fuel gas can be inside buildings and be considered unclassified locations?

Thank you
Walt.

 

[petersonra]

is the inside of your house a C1D2 area just because you have a gas water heater?

 

[CFrick]

Well, I worked 29 years for an interstate pipeline company. and this is one of those areas that no one really published a hard standard for. Our standard was that low pressure utilization gas (which we limited to 50 PSIG max) did not in itself require an area to be classified as hazardous. For example it was common to have natural gas powered generators in the Auxilary Building with the Motor Control Centers.

From the AGA standard XFO-277 Section 4: The determination of whether a location should be considered hazardous requires consideration of how combustable the product is, the likelyhood of a release and the potential size of the release. Also one needs to consider ventilation. A poorly ventilated area will accumulate even a small leak and increase your risk. Gas detection may also be used to help reduce your risk. Especially if control actions are taken in responce. API for instance allows this.

You should also consider gas detection if your fuel supply is non-odorized even at low supply pressures. This was common with the pipeline gas and we had several non-hazardous buildings with gas detection in the rooms with fuel gas.