Sorry in advance for the long post...Please excuse my ignorance as to articles 250.97, & 450 I appreciate your help!!
I will be installing a new service for an electric pump. The motor is to be 40 HP., 480 V., 3-Phase. The local utility will be metering this through a socket type 200 Amp meter base. They require a non fused disconnect ahead of the meter. I will also be installing a 480-240/120 2.5 Kva transformer for a control circuit and lighting and receptacles. All of this will be located outside on a combination of poles and unistrut.
My thoughts for this was to have a mast into the top of a disconnect (non-fused for the utility)through a hub, then to the meter base through a hub, then I would go through the side of the meter base into the side of another disconnect fused for the load (this would be the disconnect for the motor). On the load side of this disconnect I would use double lugs to feed the motor and a tap for the transformer. The transformer would come out of the side of the disconnect, and would then feed a 20 circuit panel for the single phase loads.
Now for the questions...
1.) Where would bonding bushings be required?
2.) Would it be acceptable to make a tap at the disconnect as I proposed?
3.) How should over current protection be sized in the disconnect?
I will be installing a new service for an electric pump. The motor is to be 40 HP., 480 V., 3-Phase. The local utility will be metering this through a socket type 200 Amp meter base. They require a non fused disconnect ahead of the meter. I will also be installing a 480-240/120 2.5 Kva transformer for a control circuit and lighting and receptacles. All of this will be located outside on a combination of poles and unistrut.
My thoughts for this was to have a mast into the top of a disconnect (non-fused for the utility)through a hub, then to the meter base through a hub, then I would go through the side of the meter base into the side of another disconnect fused for the load (this would be the disconnect for the motor). On the load side of this disconnect I would use double lugs to feed the motor and a tap for the transformer. The transformer would come out of the side of the disconnect, and would then feed a 20 circuit panel for the single phase loads.
Now for the questions...
1.) Where would bonding bushings be required?
2.) Would it be acceptable to make a tap at the disconnect as I proposed?
3.) How should over current protection be sized in the disconnect?