Fire pump

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gadfly56 said:
I would say "yes". Make sure that the disconnect ahead of the ATS can carry the locked rotor current for the fire pump. See NFPA 20 for calculation of the locked rotor current; don't use the usual rules of thumb.

As augie47 mentioned, the ATS is usually a combo with the fire pump controller. That way you can be sure that all the particulars are correct since we are dealing with a fire pump, and they are always a bit confusing. You could keep the upstream disconnect if you get a combo controller and ATS, but is also comes with a disconnect built in, so, why bother?
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695.10 requires that the transfer switch be listed for fire pump service. Not sure if that is different from one listed for Article 700 service or not.
 
hillbilly1 said:
Yes, but some engineers omit the ocp at the generator, though not required.....
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I never do, but I also never size it for locked-rotor amps either. It is exempt from that rule by 695.4(B)(2)(b). Be careful how you select what loads to shed. You can only shed "optional standby" loads per 695.3(D)(1).

The generator has to be pretty large compared to the fire pump in order to be able to even supply the locked-rotor amps. I think it will stall or lose voltage first.
 
I have just designed one that the existing service is OH and comes to a wireway on the exterior of the building. I tapped the conductors in the wireway and routed the new conduit and wire directly to the Fire Pump Controller.
 
don_resqcapt19 said:
Because the motor nameplate has a locked rotor code letter that is used with Table 430.7(B) to determine the actual locked rotor current.
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You want to use this table from NFPA 20 "Standard for the Installation of Stationary Pumps for Fire Protection." Why? Because the standard says so, that's why.

Locked Rotor.PNG
 
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augie47 said:
Most of the one I have seen have a service directly to the FP controller (no disconnect ahead) and the ATS is built into the FP controller but all, that can vary depending on the particulars of your install.
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The picture above that infinity sent. So, the fire pump has a dedicated panel which is shown and it's connected to the main electric supply similar to the other equipment or service disconnects?
 
zaid200 said:
The picture above that infinity sent. So, the fire pump has a dedicated panel which is shown and it's connected to the main electric supply similar to the other equipment or service disconnects?
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Yes, that would be correct. And also to the generator, if it is a combination controller/ATS.
 
dvcraven0522! said:
See attached service #2 one line diagram. Shows a FP tap section in the MDP.
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That's going to be interesting if you have to service the conductors for any reason. And if pulling the meter shuts off the power, that's a problem.
 
In that particular diagram it appears the meter is CT. Locally we make sure and label everything associated with the fire pump accordingly including any metering. It seems to get POCOs attention,
 
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