Sizing Portable Generator for Back-up Power at Wells

[allby70]

I am in need of information on how to spec a portable generator for a potable water well. I have collected the disconnect information, i.e. 3-phase, 400 amps, 600 V. However, there are two disconnects at the well house. One was on the outside of the building and is 400 amps, 600 V, and the disconnect on the inside of the building is 30 amps, 600 V.

Any information on where to go from here is greatly appreciated.

Thanks,

Allby70

 

[waross]

uh finding out the specs of the pump may be a start. Get you within a 3:1 or 4:1 size range. Knowing the type of control system as well may actually get you close to the ideal size of back-up system.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[MikeHalloran]

The 400A is presumably the size/max_load rating of the disconnect. It's not quite completely irrelevant. The 400A is the current above which the disconnect will melt, and the 600V is the voltage above which different insulation standards apply. Similarly for the inside disconnect.

Next you need to find out what the actual loads are, i.e., what loads the generator will be running, and what loads it will be required to start. You will need to list actual rated/expected voltages and currents for each load. For motors, several currents are of interest, not just one.

Loads might include:
Pump motor
Battery charger for generator's starting batteries.
Area lighting.
Service outlets and inside lighting for generator.
Beacon to make status visible at a distance.
Systems for logging, remote monitoring, control.
Transfer pump for filling generator day tank.
Fire suppression/ alarm system.
CCTV or other intrusion detection/ recording system.



Mike Halloran
Pembroke Pines, FL, USA

 

[rbulsara]

Get the pump and other load information and talk to your local generator rep.

Rafiq Bulsara

http://www.srengineersct.com