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What does he not understand about fail safe?

mshields

Silver Member
Joined
Aug 9, 2011
Messages
105
Location
Plymouth, MA
I fielded a call from a client about a gas solenoid which is operated with Normal branch power. He wanted to know if that should be on the Life Safety branch of the hospitals EES system.

a) it's not listed in 517.32 which are the only things allowed to be on LS.

b) who the hell cares. Life Safety circuits are life safety so that LS power will be there when you need it. In the case of an emergency, what we want is NOT TO HAVE POWER to the solenoid.

How could we possibly be required to provide something that serves no purpose, makes no one safer and furthermore violates the code?
 
Builder Bob said:
besides, the time it takes to switch to emergency or standby power, may shut the gas off then open the valve to un-lit pilots if not using more modern gas fueled equipment - such as kitchen stoves, stc.The switch over isn't seamless or smooth.....
Which is why if you have an electric gas valve, you need a relay that will keep the gas off, until the relay is reset. To paraphrase Builder Bob, if the gas supply is restored when the power is restored, things can go BOOM!
 
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