Two vs four pole Roto phase

[ptonsparky]

Son-in-law bought some very used three phase equipment. He had a choice of two homemade roto phase set ups and choose the higher rpm.
It works fine, but is there any advantage of one vs the other?

I warned him to be on the lookout for a replacement 3 phase motor of the roto phase/ It's old.

 

[Little Bill]

Son-in-law bought some very used three phase equipment. He had a choice of two homemade roto phase set ups and choose the higher rpm.
It works fine, but is there any advantage of one vs the other?

I warned him to be on the lookout for a replacement 3 phase motor of the roto phase/ It's old.

The 3ph motor would be on the equipment, not the RPC. Or did you mean the RPC motor?

 

[ptonsparky]

RPC motor.

This set up uses a single phase pony motor to get the three phase RPC up to speed, then the power is switched on to it. The PM is then disconnected.

 

[zbang]

Come on, old isn't necessarily bad*, or is this one getting worn? Give it a good cleaning and oiling and see how it goes.
How big is this motor?

*although my back and shoulders have something to say about that

 

[ptonsparky]

Come on, old isn't necessarily bad*, or is this one getting worn? Give it a good cleaning and oiling and see how it goes.
How big is this motor?

*although my back and shoulders have something to say about that

No, just old. 15 HP. Bearings that do actually need greased on occasion. They are open.

Mouse damaged wires at one time.

Blew the crap out of it and of course it settled in around a bare spot just inside the motor housing that now has an EG. A few sparks and SIL was sure the free help wasn't worth the cost. Opened it up and found the rubber diaphragm that sealed the pecker head had obviously had an issue for sometime. Tracking & shrinkage in the area of bared conductor.

 

[ptonsparky]

I suggested he keep an eye out for the 15 if his operation is dependent on it.

 

[Jraef]

2 pole vs 4 pole only matters for the base speed of the pony motor in that they have to match. Most 2 pole single phase motors that size will be C face pump motors, which is only important with respect to the mounting arrangement. If it’s not a C face, quick availability of a replacement 15HP foot mount 2 pole motor might be an issue some day.

 

[ptonsparky]

They had to belt up the pony to match rpm.