Thread Number: 70744
/ Tag: Modern Automatic Washers
Why not permanent split capacitor motors? |
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Post# 937220   5/8/2017 at 22:57 (2,537 days old) by chetlaham (United States)   |   | |
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Why didn't older washers like the GE filter flo and belt driven Whirlpools use permanent split capacitor motors? Same with older dishwasher like Maytag RR and D&M. Why centrifugal start or relay start? The way I see it using a PSC motor greatly simplifies wiring and eliminates a known failure point. Apply power Red to white and the motor spins one way, Yellow to white and the motor spins the other- exactly how new vertical modular washer do it. Greatly simplified and much improved.
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Post# 937242 , Reply# 2   5/9/2017 at 00:27 (2,537 days old) by tolivac (greenville nc)   |   | |
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PSC motors don't have the start torque that Cap start split phase motors have.PSC motors that I have seen are used in fans and blowers-low start torque. |
Post# 937243 , Reply# 3   5/9/2017 at 00:37 (2,537 days old) by chetlaham (United States)   |   | |
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I think you are thinking about front loads. GE FF only used a single speed motor (across all models), as most BOLs, and if dual speed is needed, there are PSC motors that come in multi speed (think table top fans). Further none of these machines had control boards. An over loaded motor be it centrifugal start or PSC would/can simply kick-off an internal overload. Also what do you mean by coupling system? PSC motors can easily be made to reverse, the remaining parts would take care of the rest much like a centrifugal start motor. The point of failure that would be eliminated is the centrifugal switch.
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Post# 937244 , Reply# 4   5/9/2017 at 00:38 (2,537 days old) by chetlaham (United States)   |   | |
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"PSC motors don't have the start torque that Cap start split phase motors have.PSC motors that I have seen are used in fans and blowers-low start torque."
This is true and now that you mention it you might be on to something. But, how much start torque did most top loaders require? Is there not a clutch? |
Post# 937247 , Reply# 6   5/9/2017 at 00:54 (2,537 days old) by chetlaham (United States)   |   | |
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Post# 937249 , Reply# 7   5/9/2017 at 01:03 (2,537 days old) by henene4 (Heidenheim a.d. Brenz (Germany))   |   | |
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But what does the flipping? Either some active switching component or the frequency of the supply. If the supply does it, their basic operating principle is the same as in the others motors you suggest they replace, thus the wiring has to be the same. If they have active switching, then they aren't more resiliant. |
Post# 937250 , Reply# 8   5/9/2017 at 01:16 (2,537 days old) by chetlaham (United States)   |   | |
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All switching is done via the timer. Here are two examples. In the first pic applying power to the red wire and not the orange makes the motor spin clockwise, and if power is applied to the orange and not the red wire, the motor spins counter clockwise. Very elegant and simply with only 3 wires leading to the motor. (Yes the first one is electronically controlled, but it will work with a mechanical timer as well.) In the second pic the motor is a bit more complicated, but if you look closely it has no centrifugal switch. Simply changing the polarity of each leg of the start winding relative to the run winding causes a change in direction. Both these motors lack a centrifugal switch.
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Post# 937252 , Reply# 9   5/9/2017 at 01:18 (2,537 days old) by chetlaham (United States)   |   | |
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Post# 937261 , Reply# 11   5/9/2017 at 01:54 (2,537 days old) by chetlaham (United States)   |   | |
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As Ive said GE filter flo washers were single Speed. As are most BOL top loaders. A PSC motor can achieve the same (approximate) 1600 RPMs as a centrifugal start motor- via the 60Hz wall supply. And to be clear- I never said a PSC would eliminate the transmission in a filter flo or any vintage washer for that matter. You would still need it to achieve agitation. And a clutch if the washer is a spin drainer.
My point- and my question- why didn't they simply drop a PSC motor directly in the place of those centrifugal/blow-out coil motors? |
Post# 937262 , Reply# 12   5/9/2017 at 01:57 (2,537 days old) by chetlaham (United States)   |   | |
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Post# 937267 , Reply# 14   5/9/2017 at 02:11 (2,537 days old) by chetlaham (United States)   |   | |
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I never said the cabling will break- just that its simpler. Eliminating the centrifugal switch is one failure point out of the picture. Clutch can go on neutral drain models as GE latter did.
But my point is still not moot- there has to be reason for choosing one over the other- hence why I am asking. |
Post# 937271 , Reply# 16   5/9/2017 at 02:29 (2,537 days old) by chetlaham (United States)   |   | |
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Post# 937272 , Reply# 17   5/9/2017 at 02:30 (2,537 days old) by chetlaham (United States)   |   | |
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Post# 937304 , Reply# 19   5/9/2017 at 08:31 (2,537 days old) by vacerator (Macomb, Michigan)   |   | |
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a reciprocating gear case for agitation necessitated a reversing motor also. |
Post# 937399 , Reply# 21   5/9/2017 at 17:13 (2,537 days old) by chetlaham (United States)   |   | |
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A US manufacturer did make a washer with an oscillating transmission and PSC motor:
www.automaticwasher.org/cgi-bin/T... |