efficiencies of appliance 3-phase brushless motors?

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Hello,

What is the ballpark efficiency range of washing machine or clothes dryer three-phase 110-volt AC motors?

I'm debating tearing a broken washing machine apart for the motor and controllers but was curious if the efficiency is too low to bother.  

Thanks,

Michael


Re: efficiencies of appliance 3-phase brushless motors?
The efficiency only depends on the motor, 1 or 3 phases.

The only difference is the power consumption on each phase.


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Re: efficiencies of appliance 3-phase brushless motors?
On Wednesday, January 9, 2019 at 12:30:54 PM UTC-8, Look165 wrote:
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...


How does the efficiency compare with brushless permanent magnet motors?

Michael

Re: efficiencies of appliance 3-phase brushless motors?
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Ours in the UK are 220/240V but get my underpants clean in 1 wash so I'd
say 100%

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terminal_crazy@sand-hill.uk

Re: efficiencies of appliance 3-phase brushless motors?
On Wednesday, January 9, 2019 at 1:26:09 PM UTC-8, Terminal_Crazy wrote:
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You have electricity in the UK?!  No way!  :o

Re: efficiencies of appliance 3-phase brushless motors?
100% efficiency doesn't exist.
A standard motor (not professional model) can barely be above 80-90%.


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Re: efficiencies of appliance 3-phase brushless motors?
On Thursday, January 10, 2019 at 1:25:05 AM UTC-8, Look165 wrote:
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Standard motor?  What's that?

Looks like 3-ph motors run from 70% @ 1/4hp to around 88% at 3hp.  I'd forgotten I had this in my notes.
http://fl600.usmotors.com/publication/?i32%9526 #

I was curious how it compared with brushless motors but I guess this will do.

Universal motors with brushes run around 30-60% efficient.
https://www.johnsonelectric.com/en/product-technology/motion/ac-motors/universal-motors?series=universal-ac-motors

The "infinitely inefficient" shaded pole motor runs around 10-20% efficient.

Michael

Re: efficiencies of appliance 3-phase brushless motors?
The ones you have at home.


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Re: efficiencies of appliance 3-phase brushless motors?
On Thursday, January 10, 2019 at 9:23:52 AM UTC-8, Look165 wrote:
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A typical American home may have:
- Shaded pole motors on desk fans and circulating air for the refrigerator.  (I was really upset when I found the old broken dishwasher in my parents' home had a giant shaded pole motor for the water pump.)
- Universal motors for dough mixers, blenders, drills and circular saws
- 3-phase motors driven by control electronics for washing machines
- brushless motors for remote-controlled model aircraft, and possibly for modern appliances

Michael



Re: efficiencies of appliance 3-phase brushless motors?
On Thu, 10 Jan 2019 09:52:03 -0800 (PST), snipped-for-privacy@gmail.com wrote:

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The reason for the big shaded pole pump motor is because they draw
pretty much the same current when stalled as when running. So if the
design allows sufficient cooling without a fan then if the pump motor
is stalled with food debris or a fork or something it won't burn up.
Granted, there are other ways to deal with stalled motors but the
shaded pole solution is simple and cheap. Except that you pay more for
the power to run the motor. This can be a wash though, so to speak.
Just save all your dirty dishes until the weather gets cold when the
extra heat from the pump motor will warm your house. Actually, I
supose a clever design would use the heat from the pump motor to help
warm the washing water.
Eric

Re: efficiencies of appliance 3-phase brushless motors?
I wonder how a fork can finish in the pump !


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Re: efficiencies of appliance 3-phase brushless motors?
wrote:

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Some dishwashers have the pump impeller under a screen that can come
loose which then allows foreign objects to contact the inpeller.
Eric

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Re: efficiencies of appliance 3-phase brushless motors?
On Thu, 10 Jan 2019 09:52:03 -0800 (PST), snipped-for-privacy@gmail.com wrote:

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Lots of air conditioners are moving to speed controlled three phase
compressor motors these days.  They've been in use for large
commercial AC's for awhile now, and plenty of the newer heat pumps use
them.  There's at least one window unit that uses a VFD and three
phase motor.  

Re: efficiencies of appliance 3-phase brushless motors?
On Thursday, January 10, 2019 at 5:02:12 PM UTC-8, default wrote:
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Oh that's a surprise!  Are they fairly close in efficiency to the electronically commutated / brushless motors then?  

Are the 3-phase motors run in open-loop, or do they require precise feedback control like the brushless motors need?

Window A/C unit?!  Which???

Thanks,

Michael

Re: efficiencies of appliance 3-phase brushless motors?
On Thu, 10 Jan 2019 18:14:57 -0800 (PST), snipped-for-privacy@gmail.com wrote:

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I doubt the motors are any more efficient than a standard 3 phase
doing the same amount of work.  BUT... they throttle back when you
don't need cooling instead of cycling on and off.

I put in a "mini-split" with an inverter (what the AC folks call their
VFD type products)  My power bill was lower than no AC and relying on
fans for cooling.  (I suspect some of that savings was due to the
refer running much less due to the lower humidity in the house)
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They have feedback of course.  Dependent on temperature.  I have a
volt/ammeter on my mini-split.  Hot summer day with a hot house I turn
on the 18,000 BTU AC and the current will hit 8-9 amps (250 volts
single phase).  After it runs for a time the current drops as it
approaches the set-point until it is chugging along with only ~2 amps
or less and on really hot days it runs continuously at 2 amps, and
begins cycling on and off if it has more capacity than it needs to
satisfy the set-point.
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LG makes them:

LW1517IVSM
14,000 BTU  
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window air conditioner, was: efficiencies of appliance 3-phase ...

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Dunno about it being three phase, but here you go:

http://www.lg.com/us/air-conditioners/lg-LW1517IVSM


  
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Re: window air conditioner, was: efficiencies of appliance 3-phase ...
On Thursday, January 10, 2019 at 6:41:12 PM UTC-8, danny burstein wrote:
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Oh neato!  Even better; it's Brushless DC (BLDC)!

"... thanks to LG's unique BLDC motor and dual inverter compressor..."

Re: window air conditioner, was: efficiencies of appliance 3-phase ...

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Annoyingly, though, Lucky Goldstar is only offering a couple
of models in the US, with ratings in the 14,000 BTU range.

I wrote to them asking if they'd please consider selling
smaller, like 5 to 10,000 ones.  Not at this time...


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Re: window air conditioner, was: efficiencies of appliance 3-phase ...
On Fri, 11 Jan 2019 14:21:27 +0000 (UTC), danny burstein

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Since they do run the compressor slower as cooling needs are met, you
probably shouldn't look at an inverter AC the same as you would a
standard AC.  If you need 10,000 BTU a 14,000 btu will throttle back
to around 20% of the power a 14K would require and that would still be
less than the 10K would use.

Of course if 5K (does anyone make one that small?) does the trick, 14K
would be way over-kill.

With standard AC units the best savings meant using the smallest AC
that would do the job.  Presumably you could live with the longer time
to cool-down... and maybe there'd be a couple of days each year when
the temp/humidity was so high that it might not keep up with your
needs.  These inverter type units are a game-changer in that respect.
And they soft-start, so you aren't pulling 40 amps to get the
compressor turning over from a dead stop.  

Re: window air conditioner, was: efficiencies of appliance 3-phase ...

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Oh, absoposolutely.  But there's still the size, material,  
and cost waste...

Of course I found these units two weeks _after_ I picked
up and installed the traditional ones in our house...


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