Midea Window AC and Growatt SPF 3000TL LVM-ES...A Bad Combo?

Smokin

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Supplying reactance power. If you look at the product label ther usually is a referance to watts used and VA"Volt Amps" used. These are usually different figures because the VA shows the reactance power used aswell as the real power. This is something that is hard to get your head wrapped around, but it does explain why an AC unit creates quite a strain on a system the has to provide reactance power without Caps. On the grid the power company provides the reactance power free of charge. They use a Capicator bank. I don't know how it works but that's the story.
 
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NOLA_Castle

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65* eco setting, swing mode activated, auto cool, auto fan.

Interesting to note that I had to swap the combo AFCI/GFCI breaker out with an AFCI because the Midea kept tripping the GFCI within a few seconds of spooling up.
No wonder....... During hurricane Ida power outage, I set my AC window for 79F and it ran for 7 hours and only consumed 1,180watt-7hrs.
 

NOLA_Castle

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65* eco setting, swing mode activated, auto cool, auto fan.

Interesting to note that I had to swap the combo AFCI/GFCI breaker out with an AFCI because the Midea kept tripping the GFCI within a few seconds of spooling up.
You may need to use 20A GFCI outlet.
 

rcrracer

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We use the Midea U 8,000BTU unit in our upstairs master bedroom overnight to keep it nice and chilly. Unit goes on right before bed and off upon waking. I took a screenshot of the wattage and PF (I am not 100% sure what the spike is about around 6am):
View attachment 64935
I believe the spike is caused when the AC needs to speed up in order to get enough lubricating oil to circulate after the compressor has been running at a lower speed(< 300? watts) for a while. With summer coming to an end, those spikes should become more frequent. The spikes with mine only go up to 410(?) watts or so. Also the PF of mine never goes above 0 .73-0.74. My unit was in the first batch manufactured. Maybe yours was manufactured later and is programmed differently.

Here is a copy of an email I sent to Midea customer service on 6/13/2020. A year and 3 months ago.
Hi,
I just received my 8,000 BTU AC. It works great, as expected. The one problem I can see is the poor P.F. The P.F. seems to range in the 0.60s. This doesn't effect me, in that I get my electricity for the local power company. But there are people who generate their own power through solar, wind, generators, etc. who might appreciate and want a high efficiency window AC with a P.F. much closer to unity. A couple of years ago I purchased an LG brand 8,000 BTU non-inverter window AC. Its P.F. is 0.99. I believe if someone is generating their own electricity, they probably would use less electricity with the LG. Is it possible to make separate U inverter models with capacitors to raise the P.F., that would be marketed to the home grown electricity people?
Unrelated. When can we expect reverse cycle(compressor heating) model window units? Self contained mini-splits in a box. Tomorrow?
Is it possible to have someone e-mail me a spreadsheet of x,y axis of efficiency vs watts for the 8,000 BTU model? No idea if such a thing exists. The possible idea is to use the LG in conjunction with the Midea, to keep the Midea in it's highest efficiency range. This was more an idea from a few years ago to be used with a mini-split and not another window AC.
Thanks.

rcrracer
 
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AdvicetotheGraduate

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I believe the spike is caused when the AC needs to speed up in order to get enough lubricating oil to circulate after the compressor has been running at a lower speed(< 300? watts) for a while. With summer coming to an end, those spikes should become more frequent. The spikes with mine only go up to 410(?) watts or so. Also the PF of mine never goes above 0 .73-0.74. My unit was in the first batch manufactured. Maybe yours was manufactured later and is programmed differently.

Here is a copy of an email I sent to Midea customer service on 6/13/2020. A year and 3 months ago.
Hi,
I just received my 8,000 BTU AC. It works great, as expected. The one problem I can see is the poor P.F. The P.F. seems to range in the 0.60s. This doesn't effect me, in that I get my electricity for the local power company. But there are people who generate their own power through solar, wind, generators, etc. who might appreciate and want a high efficiency window AC with a P.F. much closer to unity. A couple of years ago I purchased an LG brand 8,000 BTU non-inverter window AC. Its P.F. is 0.99. I believe if someone is generating their own electricity, they probably would use less electricity with the LG. Is it possible to make separate U inverter models with capacitors to raise the P.F., that would be marketed to the home grown electricity people?
Unrelated. When can we expect reverse cycle(compressor heating) model window units? Self contained mini-splits in a box. Tomorrow?
Is it possible to have someone e-mail me a spreadsheet of x,y axis of efficiency vs watts for the 8,000 BTU model? No idea if such a thing exists. The possible idea is to use the LG in conjunction with the Midea, to keep the Midea in it's highest efficiency range. This was more an idea from a few years ago to be used with a mini-split and not another window AC.
Thanks.

rcrracer

Correct on the spike to lubricate. The spike on my unit usually hits around 500 - 600 watts max. 24 hour cycle from last year:
Untitled-2-700x397.jpg

Mine is 20A GFCI and no issue, perhaps due to my temp setting is at 79F.

I am curious if my issue was the fact it was a dual function breaker. I switched to AFCI after reading that GFCI may have issues with inverter based window units.

Are you running on grid power or inverter?

Grid. I don't have solar yet. Bought an 88 yr old English Tudor style house and I am analyzing my household power usage via IotaWatt as I decrease the heat/cooling/energy loads.

Spray foam in the attic. I completely rewired the entire house and upgraded appliances.

I am very impressed with the Rheem ProTerra 50 Gal. in terms of power usage. I think solar could run it no problem:
Rheem ProTerra 50 Gal. 10-Year Hybrid.jpg

I am installing three 1:1 Mitsubishi units for the upstairs 6k, 6k and 9k for Master.

Once I believe my loads are as low as realistically possible, I'll spring for solar (hopefully the Enphase IQ8's are available by then).
 

NOLA_Castle

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Correct on the spike to lubricate. The spike on my unit usually hits around 500 - 600 watts max. 24 hour cycle from last year:
View attachment 64947



I am curious if my issue was the fact it was a dual function breaker. I switched to AFCI after reading that GFCI may have issues with inverter based window units.



Grid. I don't have solar yet. Bought an 88 yr old English Tudor style house and I am analyzing my household power usage via IotaWatt as I decrease the heat/cooling/energy loads.

Spray foam in the attic. I completely rewired the entire house and upgraded appliances.

I am very impressed with the Rheem ProTerra 50 Gal. in terms of power usage. I think solar could run it no problem:
View attachment 64949

I am installing three 1:1 Mitsubishi units for the upstairs 6k, 6k and 9k for Master.

Once I believe my loads are as low as realistically possible, I'll spring for solar (hopefully the Enphase IQ8's are available by then).
I think dual breakers may be the cause. I have 20A GFCI outlet installed at my inverter.
 

NOLA_Castle

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I have not tried Midea U in winter...... Does anybody know if this unit can be a heater?
 

PopDBop

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Here is a copy of an email I sent to Midea customer service on 6/13/2020. A year and 3 months ago.
Hi,
I just received my 8,000 BTU AC. It works great, as expected. The one problem I can see is the poor P.F. The P.F. seems to range in the 0.60s. This doesn't effect me, in that I get my electricity for the local power company. But there are people who generate their own power through solar, wind, generators, etc. who might appreciate and want a high efficiency window AC with a P.F. much closer to unity.
Well done, but no response. FWIW, my NEW 2021 Midea 8000BTU has the same PF numbers. So I don't think they've changed a thing since you purchased yours.
A couple of years ago I purchased an LG brand 8,000 BTU non-inverter window AC. Its P.F. is 0.99
Do you mind sharing the exact model number of that AC. Thanks.
 

rcrracer

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Well done, but no response. FWIW, my NEW 2021 Midea 8000BTU has the same PF numbers. So I don't think they've changed a thing since you purchased yours.

Do you mind sharing the exact model number of that AC. Thanks.
It's the first non inverter AC on that list. It's right after the Inverter LGs with a 'V'(variable) in the model name. The high power factor but relatively lower efficiency of that non inverter AC, seems to be offset by the poor power factor of the inverter ACs. It still makes cents to use an inverter AC. (Just my opinion.)
I'am really disappointed Midea didn't re-engineer the U shaped ACs after receiving my email. /s
 

rcrracer

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Correct on the spike to lubricate. The spike on my unit usually hits around 500 - 600 watts max. 24 hour cycle from last year:
View attachment 64947



I am curious if my issue was the fact it was a dual function breaker. I switched to AFCI after reading that GFCI may have issues with inverter based window units.



Grid. I don't have solar yet. Bought an 88 yr old English Tudor style house and I am analyzing my household power usage via IotaWatt as I decrease the heat/cooling/energy loads.

Spray foam in the attic. I completely rewired the entire house and upgraded appliances.

I am very impressed with the Rheem ProTerra 50 Gal. in terms of power usage. I think solar could run it no problem:
View attachment 64949

I am installing three 1:1 Mitsubishi units for the upstairs 6k, 6k and 9k for Master.

Once I believe my loads are as low as realistically possible, I'll spring for solar (hopefully the Enphase IQ8's are available by then).
Midea spikes time based. Every 32(?)minutes. Interesting. Midea AC taking an average of watts used over the last 30 minutes and then deciding if it needs to ramp up the compressor for a couple of minutes?
 

PopDBop

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It's the first non inverter AC on that list. It's right after the Inverter LGs with a 'V'(variable) in the model name. The high power factor but relatively lower efficiency of that non inverter AC, seems to be offset by the poor power factor of the inverter ACs. It still makes cents to use an inverter AC. (Just my opinion.)
I'am really disappointed Midea didn't re-engineer the U shaped ACs after receiving my email. /s
Got it. I just assumed that the LG was an inverter model.

Well, with the difference in PF's, total energy wise, yeah, could be on par with the inverter AC's. However, I chose the inverter AC Midea for the 'soft' starting and better management of power while running. Also, it is considerably more quiet than other window shakers. I suppose once I get a o-scope I can consider PF correcting the Midea. Would be nice if the had gotten back to you. I wonder who, if anyone, will lead the way in PF correcting these inverter units. I'd give it a shot. Just need to wait until I get my test gear in and configured first.
 

NOLA_Castle

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Got it. I just assumed that the LG was an inverter model.

Well, with the difference in PF's, total energy wise, yeah, could be on par with the inverter AC's. However, I chose the inverter AC Midea for the 'soft' starting and better management of power while running. I suppose once I get a o-scope I can consider PF correcting the Midea. Would be nice if the had gotten back to you. I wonder who, if anyone, will lead the way in PF correcting these inverter units. I'd give it a shot. Just need to wait until I get my test gear in and configured first.
Once you figure this out, you can sell your findings to Midea.
 
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