AC Motor from Washing Machine: 11 Wires & Sparks

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Discussion Overview

The discussion revolves around the characteristics and wiring of an AC motor extracted from a washing machine, specifically focusing on the presence of 11 wires and their functions. Participants explore the implications of these wires for power, direction, and speed, as well as seek clarification on AC motor operation.

Discussion Character

  • Technical explanation
  • Exploratory
  • Debate/contested

Main Points Raised

  • One participant notes the observation of sparks and difficulty turning the shaft when certain wire pairs are contacted, suggesting these wires relate to power.
  • Another participant proposes that the four power wires might allow for dual voltage inputs (120V or 240V), similar to some transformers.
  • A different participant explains the presence of starter and running windings, indicating that the motor can be powered at different voltages based on application.
  • One participant suggests that the wires may be related to motor direction and speed, recommending checking for a wiring diagram from the manufacturer.
  • A participant provides detailed information on how the speed of AC motors is determined by the number of pole pairs, listing synchronous speeds for various configurations.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the purpose of the wires and the operation of the motor, with no consensus reached on the exact functions of the wires or the best explanation of AC motor mechanics.

Contextual Notes

Some assumptions about the motor's design and operation remain unverified, and the discussion does not resolve the specifics of the wiring or the implications of the observed behavior.

caesius
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AC motor from washing machine, has 11 wires from it. Aside from Earth I have no idea what they are however I have observed:

If the white+blue OR the red+orange wires are bought into contact then the shaft becomes hard to turn AND I can get a few small sparks by spinning the shaft and quickly touching these wires together.

So I guess these have something to do with the power. Why four power wires though? Can someone explain AC motors better than what I've read on WIki?

Cheers.
 
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Perhaps the reason for 4 power wires is the same as why some transformers have 4 wires: to allow for either 120V or 240V ac input voltage. You wire the line voltage to the input wires one way if it's 120V, and a different way if it's 240.
 
You have starter windings (to get the rotor spinning in the right direction) and you have running windings. In addition, as Redbelly suggests, you have the option to power the motor at two different voltages, depending on application. Here's an introduction.

http://www.metalwebnews.com/howto/elec-mtr/elec-mtr.html
 
caesius said:
AC motor from washing machine, has 11 wires from it. Aside from Earth I have no idea what they are however I have observed:

If the white+blue OR the red+orange wires are bought into contact then the shaft becomes hard to turn AND I can get a few small sparks by spinning the shaft and quickly touching these wires together.

So I guess these have something to do with the power. Why four power wires though? Can someone explain AC motors better than what I've read on WIki?

Cheers.

Most likely they are for direction and speed. I've noticed that most appliances have a wiring diagram hidden inside a panel for the technicians. Perhaps you have one somewhere too. If not, check out the manufacturer's website. They'll probably have a download for it.

CS
 
The speed of the motor is determined by the number of pole pairs designed into it. AC motors are generally designed for one speed only although multi-speed AC motors are available.

A 2-pole motor (1 pair of poles) will have a synchronous speed of 3600 rpm when driven by 60 Hz supply [3000rpm when driven by 50Hz]

1800 rpm when it has 2 pole pairs.

1200 rpm with 3 pole pairs.

900 rpm with 4 pole pairs.

720 rpm with 5 pole pairs.

600 rpm with 6 pole pairs.

514.285714286 rpm with 7 pole pairs.

450 rpm with 8 pole pairs.

...and so on.

The synchronous speeds are those at which a non-synchronous motor produces no torque. The running speeds will be something like...

3450
1750
1175
870
&c

depending on the slip the motor.


Synchronous motors run at full synchronous speeds.
 

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