Transfer Switches for Fire Pumps

[ContractorDave]

Me again. Same fire pump. I was doing the flow testing, and during the 150% flow we shut the fire pump controller down to simulate the power failure and operate the transfer switch. There was no transfer and it appears that the fire pump transfer switch has somehow been run through the building transfer switch which has been temporarily disabled, which in turn has disabled the fire pump transfer switch. Now I can't find it off hand because I'm not sure if it's in 20 or 70, but I'm pretty sure that the fire pump transfer switch has to be totally independent of the building transfer switch ... or any other device for that matter. Can anyone quote a code and section for me quick....

Also, as an aside.... what do you make of 20 / 10.5.1.2 'An automatic controller shall be pressure switch actuated or nonpressure switch actuated'. Wouldn't it be simpler to say an automatic controller shall be actuated? ... Just saying.

Regards
D

 

[rbulsara]

ATS only transferes when it sees loss of power on primary source AND the alternate source is available. Verify that it is wired to start the generator if that is the alternate source.

How do you expect ATS to transfer upon shutting off the controller? How did you shut it off?

FP-ATS can be fed from a building ATS. It still has to have alternate source.


Rafiq Bulsara

http://www.srengineersct.com

 

[ContractorDave]

You engage the ATS by operating the controller disconnect. Alternately you could use the TEST function on the ATS itself but then the controller is not really down. If the building ATS is down and this inhibits operation of the FP-ATS, then you no longer have an alternate source. It is my opinion that the FP-ATS should operate the generator independent of the building ATS for this reason. I thought this was referenced in 20 or 70 but have not found it.

 

[rbulsara]

Controller is on load side of the FP-ATS. It has nothing to do with ATS control. Aren't normal and emergency sources of the FP-ATS from separate sources? Bldg ATS may disable one of them not both.

You need to get some professional help or ask a senior engineer in your company.

Rafiq Bulsara

http://www.srengineersct.com

 

[ContractorDave]

I've sought proffessional help.

No one will touch me....