repusion motor speed

[bixter]

does anyone know if 1ph repulsion motors are sensitive to voltage variation. A customer has two variable speed single phase motors the minimum speed of which he says has increased over the last year
The brushgear and commutator look OK,nothing has altered about the minimum speed position of the of the adjustment lever,its riveted to the brush plate and the stop is a pin in the end frame.

all I can think of is that there has been a change in the line voltage, at the moment it's 119v it may be that it was lower in the past

 

[Spark123]

I'd imagine so - the greater the voltage the greater the current hence the greater flux intensity so there will be more current induced into the rotor causing stronger mmf.
This will create a greater torque hence depending on load, the speed will increase.