Electric motors

[p0689109]

What are the advantages/disadvantages to using a 2pole 2800rpm motor to a 4 pole 1400 rpm motor?
I realise that to get the same pump speed I will have to have different size pullies.
Regards, Michael

 

[rtbcomp]

For a given power you get more torque with the lower speed.

Power = Torque x Speed

Also with the lower speed you use a larger motor pulley which reduces the chance of the belt slipping.

 

[ford34/2]

The rated full load torque is almost twice the rating on a 4 pole 1425 RPM motor against a 2 pole 2850Rpm

on a 3Hp BrookCrompton- a 2850 would have a full load torque of 7.3 Mn/NM
a 1425 would have a full load torque of 14.5 MN/Mn

or check the brookcrompton website.

Stan

 

[eil]

Quieter when running as a rule as well. 4 pole that is.

 

[p0689109]

Thanks for that. I thought the torque would be better, the quieter running is a bonus though. Cheers all

 

[shenion]

The larger pulley needed for the same pump RPM will negate the torque if the lower speed motor.

It might have easier starting though.