Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Shaded pole motor at half the voltage, what will happen?

Status
Not open for further replies.

neazoi

Advanced Member level 6
Joined
Jan 5, 2008
Messages
4,131
Helped
13
Reputation
26
Reaction score
15
Trophy points
1,318
Location
Greece
Activity points
37,013
I have a 240vAC 18W shaded pole motor out of a microwave oven fan.
What will happen if I run it on half the voltage (120vAC)?

The motor runs on 120vAC (much cooler), but what will happen to the speed of it?
The motor is in theory a synchronous motor (as far as I know), so even if one runs it at half voltage, it should run at the same speed (a bit less than 50Hz) due to the AC frequency being the same.
Is only the torque reduced by running the motor at half voltage and not it's speed?
 

The fact that a shaded pole motor always run at a speed below synchronous speed (3000 rpm with single pole pair) proves that it's an asynchronous rather than synchronous motor. A synchronous motor runs either at exact synchronous speed or is stalled.

Your description is nevertheless correct. Torque is considerably reduced (with about V square dependency), unloaded speed only slightly.
 

    neazoi

    Points: 2
    Helpful Answer Positive Rating
Here's the general torque characteristc of an induction motor, shown for 50, 70 and 100 % of rated voltage. Copied from Rolf Fischer, Elektrische Maschinen, Hanser 1992

1653817139057.jpeg
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top