Rotor of an 8 Pole Induction Mashine

Hallo,

Is there a difference between the rotor of an 8 pole induction Mashine and a 4 or 6 Pole Induction Mashine.

Can there be performance degragation if I use 4 Pole rotor with 8 pole stator.

the Motor power 110 Kw. The stator is rewounded as 8 pole. But I dont have any rotor. I find economic 4 pole rotors for this type of configuration.

Motor working point is 5 Hz inverter controlled (for 8 pole 70 rpm )

can there be serious problems when I use 4 Pole rotor in this configuration and working point.



thanks
Incal.

400Vac Induction Motor from a 42Vac supply

Hello,

I need to run a 400Vac 3 phase induction motor at a reduced speed from a 42Vac supply:


Working system now:

0.55kw 3 phase 400Vac motor rewired to work with 42Vac 3 phase. at 1400 rpm:

42Vac supply.


I do not want to change the coils and What I would suggest

replace 0.55Kw with a 2.2 kW
change 1400 rpm to 140 rpm
construct a simple inverter (with an IPM modul to achieve the same torque with 2.2 KW 400Vac (without changing the coils) motor with 42Vac an 140 rpm as the 0.55KW motor (with changed coils) at 1400 rpm )


Is it possible?

I can use extra air cooling on motor. It is not a problem.

I should use 42Vac according to safety regulations and I can also save the mechanical gearbox when I can increase the torque 10x eventhough I decrease the supply to 42Vac without changing the coils.

Is it a dream or is it theoretically possible


thanks:


Ferhat