Two-Phase motors for fridge condenser fans....

[turbokinetic]

<span style="font-family: inherit;" data-offset-key="cc66p-0-0"><span style="font-family: inherit;" data-text="true">Some older Westinghouse and General Electric refrigerators had fan motors which could not be run without being connected to the compressor motor. These were "two phase" motors and required the compressor motor as a rotary phase converter to power the fan.

Westinghouse and GE used this design. Others may have as well.</span></span>

<span style="font-family: inherit;" data-offset-key="26rkf-0-0"><span style="font-family: inherit;" data-text="true"></span></span>

 

 

[retro-man]

Thanks for the info. You have a wealth of knowledge and I appreciate that you are sharing this with us. I always look forward to your videos and explanations that we can all understand. This is like the adult version of show and tell. Keep them coming my friend.

Jon

 

[turbokinetic]

Thanks Jon, I appreciate it and will keep making videos as time allows!

 

[combo52]

Two Phase Condenser Fan Motors

Great video David, Some may wonder why GE, Westinghouse went to the trouble of using 2 phase fan motors when few other makers did so on their refrigerators ?

 

It took better engineering and companies that built more of the overall appliance to do this first of all because the operation of the fan motor was designed to operate with the compressor.

 

Why Brother, These 2 phase fan motor had several important advantages.

 

1 Higher starting torque, less chance of not running, better reliability.

 

2 Lower power consumption once started and running.

 

3 Cooler running = longer motor and bearing life.

 

The lower power consumption was probably the most important reason. There was a lot of competition among refrigerator builders to build refrigerators that were economical to run, we have all seen refrigerator advertising that talks about how reasonable their refrigerator is to run.

 

Frigidaire always talked about their Meter-Miser for example and FD did not use condenser fan motors on their home refs till the mid 60s at all to keep down power consumption.

 

GE & WH went for the higher performance  that having a condenser fan motor allowed when designing a refrigerator and went to the extra trouble to design it to operate economically.

 

How much power do these little motor actually draw anyway. I typical 2 wire condenser fan motor from a 60-70s refrigerator would draw around 45 watts, these 2 phase CFMs would shave off around 15 watts and draw around 30 watts.

 

Today a new refrigerator with an ECM CFM only draws about 5 watts, these new motors don't even get warm to the tough and will probably outlast the refrigerator  easily.

 

John L.

[this post was last edited: 1/23/2020-09:19]

 

[statomatic]

Very interesting, I didn't knew that kind of motor, no starting relay, no capacitor, no electronics, that's good for reliability.

 

[turbokinetic]

Reply #3 - John, good point about the efficiency of the motors. Back in the days when these were new, electricity cost was far higher than it is today (adjusted for inflation etc.). Now-a-days, energy efficiency claims are nothing more than marketing gimmicks to make a sale and then cost you more in failures and repairs than any efficiency gains save. The late 30's through 40's fridges definitely used little power and used that power on a fairly light duty-cycle - and with fewer and less costly repairs than what is available today.

 

Reply #4 - Most of these old small motors are very reliable. It seems their Achilles heel is the power cable. The cables deteriorate and the insulation crumbles. Assuming you have learned a repair process to replace the wiring, there isn't much that will actually destroy them. The stator winding is "impedance protected" which means that even if the rotor is stuck and can not rotate, the current flow through the winding is not high enough to burn out the motor. Once the blockage is removed (jammed fan blade, dried up oil etc.) the motor will take off like nothing happened.