Car hoist motor

[powerplay]

I had someone tell me they were advised to use an 12A, 240volt single phase motor I believe with 3450 RPM, to replace an 3 phase 1725 RPM motor on a car hoist. The speed would be faster they say, but is it safe for the hydraulics? I've heard this scenario before due to the limited options on single phase motors to replace a 3 phase one in an building with only single phase....any feedback?..comments?

 

[GeorgeB]

I had someone tell me they were advised to use an 12A, 240volt single phase motor I believe with 3450 RPM, to replace an 3 phase 1725 RPM motor on a car hoist. The speed would be faster they say, but is it safe for the hydraulics? I've heard this scenario before due to the limited options on single phase motors to replace a 3 phase one in an building with only single phase....any feedback?..comments?

Many cheap gear pumps are rated for 3600 rpm service. The issues are with fluid viscosity and maintaining net positive suction head (NPSH). Losses will be higher in the plumbing, but with the light use these see, he will probalby be ok.

The horsepower required at "3600" will be 2x the horsepower required at "1800" at the same pressure load. I'd guess your 12A motor is 2 HP? It might have a hard time starting if under load. 3 phase motors deliver much better starting torque than single phase. What was the original motor power rating?

 

[G._S._Ohm]

The hydraulics should run hotter at the higher speed. The drag due to fluid viscosity might increase as RPM cubed, so it'd be 8x higher. Sounds iffy to me.

 

[Open Neutral]

Can you find a 1725 HP 2HP motor instead?