40 amp 480 Volt Three Phase "Baler"

[powerplay]

Hello all,

We are relocating an Three Phase 480 volt Baler on an 3 pole 60 amp breaker used continuously for recycling on an existing 75 kva 600 volt to 480 volt Transformer to another Building with only 120/208 volts. We have decided to purchase an 30 kva 208 volt to 480 volt Transformer for only this equipment. Are there any concerns when we downsize the present 75 kva source to accommodate only the "Baler" on an 30 kva 208 volt to 480 volt Transformer to an Panel with an 3 pole 60 breaker ?

Thank you for any feedback !

 

[ptonsparky]

The 60 amp breaker means little. We don't know what size the motor actually is. Motor HP would be better or perhaps a nameplate of the unit.
The 30 KVA has an approx amperage of 36 amps on the 480 side. The 75 KVA, about 90. Missing a lot of details.

 

[augie47]

I would have concern,.\
I agree with ptonsparky that actual motor data would be required but being on a 60 amp bteaker one could assume about a 25hp motor which would be roughly 30 kw but balers tend to tax motors heavily. Without a ,lot more data and a conversion with an engineer at the transformer company I would be very leery.

 

[powerplay]

It was verified a Three Phase 480 volt 26kw 39.5 amp Baler, and that an 45kw 208 volt to 489 isolation transformer would support the load.

 

[Jraef]

If the baler uses a hydraulic pump, the starting kVA of that motor can be problematic for a transformer that small and the pump may stall. The quick and dirty rule of thumb is to have the transformer kVA be 2 to 3x the motor HP. 26kW would equate to about 35HP, but assuming that’s the whole machine and the main motor is maybe only 25HP, that transformer is a still probably too small.

 

[kwired]

If the baler uses a hydraulic pump, the starting kVA of that motor can be problematic for a transformer that small and the pump may stall. The quick and dirty rule of thumb is to have the transformer kVA be 2 to 3x the motor HP. 26kW would equate to about 35HP, but assuming that’s the whole machine and the main motor is maybe only 25HP, that transformer is a still probably too small.

Soft start or VFD would help with this? Presuming the pump starts or can be started "unloaded"?

 

[Jraef]

Soft start or VFD would help with this? Presuming the pump starts or can be started "unloaded"?

Soft start or drive might help, if there is one.

Hydraulic pumps are positive displacement, so starting is always “loaded” in that the fluid always has to move, even if just into an accumulator. That’s why it’s important to have enough power available to start them.

 

[kwired]

Soft start or drive might help, if there is one.

Hydraulic pumps are positive displacement, so starting is always “loaded” in that the fluid always has to move, even if just into an accumulator. That’s why it’s important to have enough power available to start them.

Understand, but is possible to have starting/bypass modes that will result in less loading than in certain running conditions.