hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
I have a lift station the I have to wire and supply the service to, I am having problems with the engineers specs, and installed main breaker in the control cabinet.
The control cabinet has already been built, and ready for ship to site.
The problem is I believe the 100 amp main breaker is to small that they have installed.
We have two 10 hp pumps that for the most time will run one at a time, but if load dictates, can be both brought on-line, so the supply will have to supply both pumps, 3-phase is not available in the area so the engineers installed VFD's to supply 3-phase to the pumps through PLC control.
The pump motors are 10 HP with a FLA of 28.4 amps on the motor label @ 230 volts 3-phase
If you figure the amps at 240 volts single phase via the 746 watts per HP you end up with 31 amps per pump, (which I think is what their doing)
But at 28.4 FLA Im seeing just over 49 amps per pump, and this is not including panel heater, PLC and control loads, and loss across the VFD's?
I thinking I need a 150-200 single phase amp service, and at least a 150 amp main in the control panel?
I had problems before with the wiring in control panels from this engineer before, I'm just trying to come up with why they think a 100 amp 240 volt single phase service will hold this installation?
The control cabinet has already been built, and ready for ship to site.
The problem is I believe the 100 amp main breaker is to small that they have installed.
We have two 10 hp pumps that for the most time will run one at a time, but if load dictates, can be both brought on-line, so the supply will have to supply both pumps, 3-phase is not available in the area so the engineers installed VFD's to supply 3-phase to the pumps through PLC control.
The pump motors are 10 HP with a FLA of 28.4 amps on the motor label @ 230 volts 3-phase
If you figure the amps at 240 volts single phase via the 746 watts per HP you end up with 31 amps per pump, (which I think is what their doing)
But at 28.4 FLA Im seeing just over 49 amps per pump, and this is not including panel heater, PLC and control loads, and loss across the VFD's?
I thinking I need a 150-200 single phase amp service, and at least a 150 amp main in the control panel?
I had problems before with the wiring in control panels from this engineer before, I'm just trying to come up with why they think a 100 amp 240 volt single phase service will hold this installation?