Air Compressor Packge Unit

[lbudden]

I have an air compressor to wire that is an air compressor motor, dryer and fan motor in a single unit. It came from Belgium with a motor that is "Inverter duty", and the nameplate says 156 amps at 460 volt. The schematic shows 160 amp as maximum fuse size. There is no nameplate for minimum circuit amps.
Is the wiring for this treated as you would for an air conditioner or motor, where you size the conductors on the 156 amps but upsize the OCP for inrush? (By the way, it has a soft start VSD) Is there NEC reference for these type of "packaged units"?
Also if there is a 300 amp breaker available to feed this, and we put a 200 amp disc. fused at 150 amp, can the entire branch circuit be rated 156 amp? Then the 300 amp breaker is only for disconnecting, short circuit and fault while the 150 amp fuses protect the conductors and package unit?
Thanks for any advise anyone may have...

 

[wolfman56]

Re: Air Compressor Packge Unit

Before you get too deep into this you should check with you're AHJ and see if he will even accept the unit. Also Is this unit designed for 50 cps as some European motors are? That changes everything.
I went through this with a printing press from Holland. We had to use transformers to tweak the voltages in order to compensate for the difference in CPS. Then the AHJ, (Washington State) made us bring in UL to certify the unit.

 

[lbudden]

Re: Air Compressor Packge Unit

Now that you mention the CPS, the nameplate had the following listed:

HZ V KW A PF RPM NM

122 400Y 37 94 0.64 3640 97
148 460Y 45 91 0.69 4420 97
161 400Y 50 97 0.83 4800 100
177 460Y 55 95 0.81 5280 100

I didn't understand the CPS/HZ column with these values other than the 50/60 you normally see.

 

[hbiss]

Re: Air Compressor Packge Unit

...I didn't understand the CPS/HZ column with these values other than the 50/60 you normally see.

Is that the motor nameplate? Could it be because of the variable speed drive?

 

[lbudden]

Re: Air Compressor Packge Unit

<<Is that the motor nameplate? Could it be because of the variable speed drive?>>

Yes, those are the hertz on the compressor motor, not on the unit nameplate. I will have to see what hertz was on the nameplate of the whole unit, I don't remember seeing it.