7.9 Emergency Lighting Fuel Source - Intentional Removal!!!

[Billgas]

Hi All -
I have a head scratching "conflict" between NFPA 101-2000 and DOT 192.167.

We installed, use and test a natural gas fueled emergency generator and transfer switch system to satisfy NFPA 101 7.9 Emergency Lighting.

Another code DOT 192.167 calls for us to block and remove the fuel source in the event of an emergency shutdown.

Here are the applicable sections:

§192.167 Compressor stations: Emergency shutdown.

(a) Except for unattended field compressor stations of 1,000 horsepower (746 kilowatts) or less, each compressor station must have an emergency shutdown system that meets the following:
(1) It must be able to block gas out of the station and blow down the station piping.

DOT says to intentionally block and vent fuel gas from the station - and emergency generator. Does normal connection to the utility cover the installation for emergency lighting (see the last paragraph of A.7.9.2.2)? Is there any requirement for addressing a two-failure mode analysis, where there both a power failure and an Emergency Shutdown would would leave the building without emergency light.

An analogous situation can occur when an emergency generator is not available due to planned or unplanned maintenance and repair.

Thanks,
Bill

 

[stookeyfpe]

You installed a 750 KW NG generator for emergency lighting? Must be a huge facility.

Your citation is missing the CFR number. Such a large compressor sounds like its part of a NG distribution pipeline. Was the life safety branch circuit connected to this generator?

 

[rbulsara]

As far as I have known NEC has not permitted natural gas fired generators for Life safety emergency use, which includes emergency lights, for the exact reasons. There is an exception, which I have not seen used or ever sought to use.

It is still there in 2008 Code, Article 700.12. Compressors may not fall under life safety systems.



Rafiq Bulsara

http://www.srengineersct.com