SPC on a Century motor label

[steamingspud]

Hiyah folks,

I guess the Century electric motors site crashed sometime in the past 24 hours, I was on it yesterday... anyways.

I'm doing a project with a three-phase motor on a gearbox for a rolling mill, and in order to run this, I need a three-phase generator of sorts. In order for this to work, the motor that I am turning into a rotary phase converter needs a higher horse power rating than that of the gearbox. My problem is the motorI got for the RPC has a horsepower rating of SPL. I've seen in this forum a bunch of answers, such as "special," "split-phase," "sound-pressure level," and none of these answer the question. I don't think I have the stuff to find the power factor of the motor, so there's not enough info to just calculate it...

Label reads:
serial:BZ08-10
Part: 8-181128-02
Type: SC_______FR: Y56Y________
Hp: SPL________PH: 3___________
HZ: 60_________RPM: 3450______
Volts: 460/208-230_____________
amps:6.6/13.4-13.2_____________
Time: CONT___EnclP___Form:KHH


I skipped a few things that I don't think important. Sorry if I'm in the wrong forum

 

[petersonra]

Hiyah folks,

I guess the Century electric motors site crashed sometime in the past 24 hours, I was on it yesterday... anyways.

I'm doing a project with a three-phase motor on a gearbox for a rolling mill, and in order to run this, I need a three-phase generator of sorts. In order for this to work, the motor that I am turning into a rotary phase converter needs a higher horse power rating than that of the gearbox. My problem is the motorI got for the RPC has a horsepower rating of SPL. I've seen in this forum a bunch of answers, such as "special," "split-phase," "sound-pressure level," and none of these answer the question. I don't think I have the stuff to find the power factor of the motor, so there's not enough info to just calculate it...

Label reads:
serial:BZ08-10
Part: 8-181128-02
Type: SC_______FR: Y56Y________
Hp: SPL________PH: 3___________
HZ: 60_________RPM: 3450______
Volts: 460/208-230_____________
amps:6.6/13.4-13.2_____________
Time: CONT___EnclP___Form:KHH


I skipped a few things that I don't think important. Sorry if I'm in the wrong forum

I think it means "special".

It probably is a 5 HP motor but it has some kind of goofy rating that is basically meaningless outside of one or two applications.

 

[hurk27]

I think it means "special".

It probably is a 5 HP motor but it has some kind of goofy rating that is basically meaningless outside of one or two applications.

This special rating is commonly found on air compressors who try to not give the real rating of the air compressor, although anyone with an electrical background can do the math to figure out they are not getting what they are paying for, the last one I saw that had a current rating of 6.6 amps at 460 volts was claimed to have a 10hp effective output even though the motor was only capable of 5hp once you figure in all the losses and a PF of 2%, a 3450 rpm motor is also only a two pole motor, the funny thing was the CFM that they contributed to the 10hp rating was when the compressor was only at 75# psi not the full 150# psi the compressor was rated at, the bad thing was no way would it run on 208 as an air compressor is a high torque application and a 230 volt motor would run hot and burn up unless you increase the pulley size ratio to lower the rpms of the compressor it would just take longer to build up pressure, but at least it would allow the motor to run without over loading it.

I question using this type of motor on a rolling mill as the ambient temperature in the environment could cause the motor to run hotter then it is rated for, and with out no temperature ratings on the label you would not have any idea if the environment will be too hot for this motor if it has a 120?c rise temp over ambient or even a 130?c and the environment is over 45?c you could end up with the motor running to hot for its winding insulation.