Fire Pump Connection in building with Primary Service (15kV)

[LibertyEngineering]

I have a project where the power company is dictating, due to loads, we are required to take a medium voltage service (15kV). Their guidelines allow connection ahead of the primary service disconnect for a fire pump circuit to feed a dedicated fire pump transformer. I have never done one of these with a medium voltage service and wondering how this looks. They require cold sequence metering for the service itself and want the fire pump load to be metered as well via a separate set of metering transformers in a separate enclosure. The medium voltage service will be inside and will likely use a sub-station transformer. Other option is to add 2 LIS switches after the meter and feed step down transformers from the LIS switches. Would the Fire pump section of the medium voltage gear just be a tap that feeds a transformer. Does not feel right not having a fused LIS dedicated to feeding the transformer. I could size that fuse for locked rotor current. It is only a 25HP fire pump @ 13kV 3 – phase fuse would be pretty small, 10A. I am struggling with this one. Does anyone have any example single line diagrams for this type of set up?

 

[JoeStillman]

Sounds like they are permitting a dedicated transformer. But does that mean they require it?

I have fed fire pumps from HT services before by connecting upstream of transformer secondary mains. If you design the secondary gear right, you can comply with all the Codes.

 

[LibertyEngineering]

Sounds like they are permitting a dedicated transformer. But does that mean they require it?

I have fed fire pumps from HT services before by connecting upstream of transformer secondary mains. If you design the secondary gear right, you can comply with all the Codes.

So basically as standard fire pump tap section ahead of the main circuit breaker section in the gear fed from the transformer. I thought since the service disconnect is technically now part of the HT I would need to feed ahead of that. I would much rater prefer to add a fire pump tap section to the secondary gear. Seems much cleaner.

 

[dkidd]

See

Application Guide for Electric Fire Pump Controllers

Application Guide for Electric Fire Pump Controllers

www.nema.org

It shows a number of acceptable arrangements.