EDAboard.com | EDAboard.de | EDAboard.co.uk | WTWH Media

efficiencies of appliance 3-phase brushless motors?

Ask a question - edaboard.com

elektroda.net NewsGroups Forum Index - Electronic for beginners - efficiencies of appliance 3-phase brushless motors?

Goto page Previous  1, 2

danny burstein
Guest

Fri Jan 11, 2019 3:45 pm   



In <ec417b1c-18c8-4f85-8284-662e712c23b1_at_googlegroups.com> mrdarrett_at_gmail.com writes:

Quote:
On Thursday, January 10, 2019 at 6:41:12 PM UTC-8, danny burstein wrote:
In <3iqf3ehsptonbtlf27vd0nqqptq6dd2um3_at_4ax.com> default <default_at_defaulter.net> writes:

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.

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

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

Oh neato! Even better; it's Brushless DC (BLDC)!

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


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...


--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb_at_panix.com
[to foil spammers, my address has been double rot-13 encoded]

default
Guest

Fri Jan 11, 2019 4:45 pm   



On Thu, 10 Jan 2019 18:14:57 -0800 (PST), mrdarrett_at_gmail.com wrote:

Quote:
On Thursday, January 10, 2019 at 5:02:12 PM UTC-8, default wrote:
On Thu, 10 Jan 2019 09:52:03 -0800 (PST), mrdarrett_at_gmail.com wrote:

On Thursday, January 10, 2019 at 9:23:52 AM UTC-8, Look165 wrote:
The ones you have at home.


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

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.


Oh that's a surprise! Are they fairly close in efficiency to the electronically commutated / brushless motors then?


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)
Quote:

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


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.
Quote:

Window A/C unit?! Which???


LG makes them:

LW1517IVSM
14,000 BTU
Quote:

Thanks,

Michael


default
Guest

Fri Jan 11, 2019 4:45 pm   



On Thu, 10 Jan 2019 22:04:29 -0800 (PST), mrdarrett_at_gmail.com wrote:

Quote:
On Thursday, January 10, 2019 at 6:41:12 PM UTC-8, danny burstein wrote:
In <3iqf3ehsptonbtlf27vd0nqqptq6dd2um3_at_4ax.com> default <default_at_defaulter.net> writes:

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.

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

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


Oh neato! Even better; it's Brushless DC (BLDC)!

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


I installed my own inverter (VFD 3-ph) "mini-split" in 2002. I saw
them in an episode of "This Old House" (or something like that) and
figured I could DIY the installation. I did call an AC contractor but
back then they didn't want to touch it and denigrated the whole idea
and told me how inferior they were. (the same guys are selling them
and promoting them today)

My 18,000 BTU cost me $1,300 with all the parts except for the
electrical disconnect and wiring, and I did need to buy some metric
wrenches and a flaring tool. It is a heat-pump so I just disconnected
the base-board electrical heater and ran the line outside to a
disconnect and didn't run new wiring to the breaker panel. (they say
it needs 20 amp service but I've never seen it go over 10 amps, and it
is soft-start)

I built a small deck out some scraps of treated lumber to keep it off
the ground, but they sell brackets so you can mount the compressor on
the side of the house or put in on a small slab. I did not pump down
the system with a vacuum (the pump and gauges would have cost $350).
Instead I purged it with the pre-charged gas that was already in the
compressor unit - let it leak for a few seconds until the refrigerant
displaced the air in the lines. (they claim you need a vacuum pump in
the ads, but had instructions for purging in the literature that
shipped with it) It has been working like a champ for ~16 years now
so I guess purging works.

I did all the work myself and it took me a few days to finish the job
but I'm tickled with the results. (it is running right now to warm
the room to 65 - outside is 30 current is down to 2 amps - it does
have to cycle on and off since the ambient and outside coils are below
freezing and it needs to defrost from time to time)

I did have trouble flaring the copper tubes. I bought the flaring
tool at an auto parts store and had flared tubes before without
problems, but the tubing that shipped with the unit was not dead-soft
and tended to tear. A little silicone grease on the point of the
flaring tool fixed that. (1/4" copper for high pressure liquid
refrigerant and 1/2" gas return)

My wife has her own house and since she saw my installation she wanted
one too. She got 2 completely independent units (one compressor can
serve multiple inside units) One of hers is 10,000 and the other
12,000 BTUh. She paid $4,000 for the units with professional
installation including the electrical work and wiring. Her
compressors are mounted on brackets on the brickwork of her house.
Her units are newer and when they are running they are quiet - can't
tell they are on. Mine has a pretty aggressive fan and that makes
some noise, but then my system cools/heats the house faster than hers
does.

Now I want an LG inverter style for my bedroom window unit.

default
Guest

Fri Jan 11, 2019 5:45 pm   



On Fri, 11 Jan 2019 14:21:27 +0000 (UTC), danny burstein
<dannyb_at_panix.com> wrote:

Quote:
In <ec417b1c-18c8-4f85-8284-662e712c23b1_at_googlegroups.com> mrdarrett_at_gmail.com writes:

On Thursday, January 10, 2019 at 6:41:12 PM UTC-8, danny burstein wrote:
In <3iqf3ehsptonbtlf27vd0nqqptq6dd2um3_at_4ax.com> default <default_at_defaulter.net> writes:

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.

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

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

Oh neato! Even better; it's Brushless DC (BLDC)!

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

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...


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.

danny burstein
Guest

Fri Jan 11, 2019 6:45 pm   



In <cbgh3e9lgca6v3gjvhi8fk2614cfu8q59j_at_4ax.com> default <default_at_defaulter.net> writes:

Quote:
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...

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.


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...


--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb_at_panix.com
[to foil spammers, my address has been double rot-13 encoded]


Guest

Fri Jan 11, 2019 6:45 pm   



On Fri, 11 Jan 2019 00:00:56 +0100, Look165 <look165_at_numericable.fr>
wrote:

>I wonder how a fork can finish in the pump !
Some dishwashers have the pump impeller under a screen that can come
loose which then allows foreign objects to contact the inpeller.
Eric

Quote:

etpm_at_whidbey.com a écrit le 10/01/2019 à 23:53 :
On Thu, 10 Jan 2019 09:52:03 -0800 (PST), mrdarrett_at_gmail.com wrote:

On Thursday, January 10, 2019 at 9:23:52 AM UTC-8, Look165 wrote:
The ones you have at home.

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

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



Guest

Fri Jan 11, 2019 7:45 pm   



On Friday, January 11, 2019 at 8:30:07 AM UTC-8, default wrote:
Quote:
On Fri, 11 Jan 2019 14:21:27 +0000 (UTC), danny burstein
dannyb_at_panix.com> wrote:

In <ec417b1c-18c8-4f85-8284-662e712c23b1_at_googlegroups.com> mrdarrett_at_gmail.com writes:

On Thursday, January 10, 2019 at 6:41:12 PM UTC-8, danny burstein wrote:
In <3iqf3ehsptonbtlf27vd0nqqptq6dd2um3_at_4ax.com> default <default_at_defaulter.net> writes:

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.

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

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

Oh neato! Even better; it's Brushless DC (BLDC)!

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

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...

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.


Home Depot has a 5kbtu window AC unit for around $100 or $130; I forget exactly.

I went ahead and took apart my broken Sears/Kenmore front load washing machine (turns out it has broken shocks, among other problems) and pulled out the motor. It's a J52AAC-0102 if anyone's curious.

I was about to ask if anyone knows of circuits to play with 3-phase motors but I found something already.

https://hackaday.com/2012/01/19/building-a-variable-frequency-drive-for-a-three-phase-motor/

http://blog.hardcore.lt/mic/driver-schematics.png

Unfortunately that MC3PHAC controller is at End Of Life due to low sales.

Michael

default
Guest

Fri Jan 11, 2019 8:45 pm   



On Fri, 11 Jan 2019 10:34:01 -0800 (PST), mrdarrett_at_gmail.com wrote:

Quote:
On Friday, January 11, 2019 at 8:30:07 AM UTC-8, default wrote:
On Fri, 11 Jan 2019 14:21:27 +0000 (UTC), danny burstein
dannyb_at_panix.com> wrote:

In <ec417b1c-18c8-4f85-8284-662e712c23b1_at_googlegroups.com> mrdarrett_at_gmail.com writes:

On Thursday, January 10, 2019 at 6:41:12 PM UTC-8, danny burstein wrote:
In <3iqf3ehsptonbtlf27vd0nqqptq6dd2um3_at_4ax.com> default <default_at_defaulter.net> writes:

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.

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

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

Oh neato! Even better; it's Brushless DC (BLDC)!

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

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...

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.


Home Depot has a 5kbtu window AC unit for around $100 or $130; I forget exactly.

I went ahead and took apart my broken Sears/Kenmore front load washing machine (turns out it has broken shocks, among other problems) and pulled out the motor. It's a J52AAC-0102 if anyone's curious.

I was about to ask if anyone knows of circuits to play with 3-phase motors but I found something already.

https://hackaday.com/2012/01/19/building-a-variable-frequency-drive-for-a-three-phase-motor/

http://blog.hardcore.lt/mic/driver-schematics.png

Unfortunately that MC3PHAC controller is at End Of Life due to low sales.

Michael


Ebay has some cheap VFD controllers starting at ~$50 (for 220VAC)
Single phase in, three phase out.

Ralph Mowery
Guest

Sat Jan 12, 2019 12:45 am   



In article <3iqf3ehsptonbtlf27vd0nqqptq6dd2um3_at_4ax.com>,
default_at_defaulter.net says...
Quote:

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.



At least 10 or more years ago the heat pumps and probably other
heating/cooling systems moved to speed controlled motors. There is a
way where the motors start up slow to move the air that is sort of a way
to cheat on the 'government efficency' numbers.

Ralph Mowery
Guest

Sat Jan 12, 2019 12:45 am   



In article <b2ch3e5co7auvip27jsmtcc141gn80l905_at_4ax.com>,
default_at_defaulter.net says...
Quote:
I built a small deck out some scraps of treated lumber to keep it off
the ground, but they sell brackets so you can mount the compressor on
the side of the house or put in on a small slab. I did not pump down
the system with a vacuum (the pump and gauges would have cost $350).
Instead I purged it with the pre-charged gas that was already in the
compressor unit - let it leak for a few seconds until the refrigerant
displaced the air in the lines. (they claim you need a vacuum pump in
the ads, but had instructions for purging in the literature that
shipped with it) It has been working like a champ for ~16 years now
so I guess purging works.



It is not so much if purging works or not. For around 20 or 30 years it
has been illegal to dump any refrigerent into the atmosphere. The claim
by the government is that it depleats the ozone layer. There is a big
fine for doing that.

default
Guest

Sat Jan 12, 2019 12:45 pm   



On Fri, 11 Jan 2019 17:59:02 -0500, Ralph Mowery
<rmowery28146_at_earthlink.net> wrote:

Quote:
In article <b2ch3e5co7auvip27jsmtcc141gn80l905_at_4ax.com>,
default_at_defaulter.net says...
I built a small deck out some scraps of treated lumber to keep it off
the ground, but they sell brackets so you can mount the compressor on
the side of the house or put in on a small slab. I did not pump down
the system with a vacuum (the pump and gauges would have cost $350).
Instead I purged it with the pre-charged gas that was already in the
compressor unit - let it leak for a few seconds until the refrigerant
displaced the air in the lines. (they claim you need a vacuum pump in
the ads, but had instructions for purging in the literature that
shipped with it) It has been working like a champ for ~16 years now
so I guess purging works.



It is not so much if purging works or not. For around 20 or 30 years it
has been illegal to dump any refrigerent into the atmosphere. The claim
by the government is that it depleats the ozone layer. There is a big
fine for doing that.


The R134a refrigerant can be bought by anyone and they sell one pound
cans for recharging car AC's. Or you can go on-line and order a 30 lb
cylinder without a license. (unlike R-30)

The info I found said it was a greenhouse gas, but not ozone
depleting. The information that shipped with it gave the reason for
purging to be: moisture freezing in the evaporator valve and blocking
it. (the "valve" is often just a length of copper capillary tubing)
The AC people said it is necessary to prevent acids from forming and
destroying the compressor.

I've no doubt that it is better to recycle it, and better to draw all
the moisture and air out with a pump. But given the number of cars on
the road leaking it by the pound, I figure my one-time loss of an
ounce or two shouldn't matter.

AND if you still want to say it is wrong, read the label on a can of
computer "Dust-Off." There are people on Utoobe who buy that stuff
because it is cheaper than the same stuff labeled as a refrigerant.

The units do have desiccant dryers in the compressors to eliminate
moisture.

Back in the day... the EPA forced AC contractors to buy some pretty
damn expensive refrigerant recovery equipment, to deal with the hassle
of sending it off to be recycled into fresh clean stuff, and to take
classes to learn the law and how to recycle to get a license. That
same regulation is capitalized by AC contractors today that see
DIYer's cutting into profits that they think are rightfully theirs.
Now it is political, cans of "dust-off" not withstanding. The other
faction with a vested interest are the thousands of auto-repair
businesses who don't want to spend the money on specialized equipment
or hire specialists to work on AC.

default
Guest

Sat Jan 12, 2019 12:45 pm   



On Fri, 11 Jan 2019 17:51:42 -0500, Ralph Mowery
<rmowery28146_at_earthlink.net> wrote:

Quote:
In article <3iqf3ehsptonbtlf27vd0nqqptq6dd2um3_at_4ax.com>,
default_at_defaulter.net says...

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.



At least 10 or more years ago the heat pumps and probably other
heating/cooling systems moved to speed controlled motors. There is a
way where the motors start up slow to move the air that is sort of a way
to cheat on the 'government efficency' numbers.

Huh? That doesn't sound believable. An AC runs and uses power which
is easily measured in watts, can be used to cool water or air which
have known caloric absorption rates for measurable temperature
rise/fall... which, in turn, can be used to calculate power doing
useful work.

That is how microwave ovens are tested for efficacy. How much
temperature rise in a known quantity of water is produced in a
specific amount of time. An AC is playing the same game, and the same
measuring techniques can be used to test efficiency. The testing
equipment would cost a little more.

Soft start is generally just easier on the mechanical components and
eliminates the large power spike starting induction motors create.
Eliminates the centrifugal switches, and is easier on the power source
(wiring and circuit breakers)

Soft start can also provide feedback in AC systems to avoid
overloading compressors with a lot of back-pressure when starting.
(eliminating the pressure switches or thermal overloads AC's and
refrigerators currently use)

Are you sure you aren't confusing this with Auto computers programmed
to run lean in testing but richer in normal driving?

Goto page Previous  1, 2

elektroda.net NewsGroups Forum Index - Electronic for beginners - efficiencies of appliance 3-phase brushless motors?

Ask a question - edaboard.com

Arabic version Bulgarian version Catalan version Czech version Danish version German version Greek version English version Spanish version Finnish version French version Hindi version Croatian version Indonesian version Italian version Hebrew version Japanese version Korean version Lithuanian version Latvian version Dutch version Norwegian version Polish version Portuguese version Romanian version Russian version Slovak version Slovenian version Serbian version Swedish version Tagalog version Ukrainian version Vietnamese version Chinese version Turkish version
EDAboard.com map