Running Sanyo mini-split on MSW inverter?

XRinger

Since the Sanyo I have using is using 'inverter technology'..

I'm wondering if other Sanyo owners here have used MSW inverters to supply their Sanyo mini-spit, or other brand mini-split AC/heatpump??

I'm thinking of getting one of the low cost 'StackAble' 2500 watt MSW units off Ebay. (48vdc to 230vac model).

Thanks,
Rich

waynefromnscanada

Re: Running Sanyo mini-split on MSW inverter?

XRinger wrote: »

Since the Sanyo I have using is using 'inverter technology'..

I'm wondering if other Sanyo owners here have used MSW inverters to supply their Sanyo mini-spit, or other brand mini-split AC/heatpump??

I'm thinking of getting one of the low cost 'StackAble' 2500 watt MSW units off Ebay. (48vdc to 230vac model).

Thanks,
Rich

Do not be surprised if the Modified Square Wave inverter you are looking at (Called Modified Sine Wave by those selling them) causes the early demise of your mini-spit. The "inverter technology" Sanyo speaks of, refers to the electronics that control and power the compressor motor, and does NOT indicate that it will not smoke if operated on MSW.
MSW is not the way to go with your mini-split, for other reasons as well.

XRinger

Re: Running Sanyo mini-split on MSW inverter?

Because I do not have the schematics, I do not know if there are any 50 or 60 Hz transformers on the main board.

BUT, If there weren't any transformers or AC motors at all, and the system converted all AC to DC using diodes,
what else could cause problems?

And, what are those "for other reasons as well." ??

Thanks,
Rich

PS:
Right now, I'm using unstable grid power that has a tendency to climb up around 250-256 vac.
My TED alarm could not be used at 140 vac, it kept going off at random times. (power spikes maybe)?
Setting the trip-point for 199 vac seems to have cured the problem.
This summer, they will actually turn UP the voltage for summer AC use.

Photowhit

Re: Running Sanyo mini-split on MSW inverter?

FWIW - I had one of these "semi pure sine wave" how I think they discribe them, in a 1400 watt model sold by one of the people(dmssgs) currentltly sell these "stackable" units. At that time they also had a link to curve produced by the 1400 watt version and it looked much more like a curve than a stepped, but was a bit choppy. I'll take a look and see if I can find a link.

MY experience was mixed, I bought the 24v 1400 watt unit for @ $100 or 120 shipped. It worked fine for about a year and kicked over and ran my window AC without a problem, near the end of the first year at the begining of summer the internal cooling fan died, I cracked the case and since I work long hours in the summer, I just layed the case open with a 6" O2 Cool fan running steady. It made it through the summer and the next winter and I finally replaced it with a true sine wave inverter. The inexspensive inverter did allow me the time to shop and get a great price on the inverter, So I have no regrets, and saved money in the long run. Would I do it again? Likely if I ever switch to a 48 volt system, hoping to replace it with in a year and keep it as a back up.

The Ac has shown no ill effects from the summer running on this inverter, my fridge had a thermostat go out the next summer and a month after it was repaired the compressor went out, don't know if either was from indirect abuse from this inverter. It was a small 4cuf fridge.

Photowhit

Re: Running Sanyo mini-split on MSW inverter?

OK I found the link to a PDF of the 1400 watt inverter, with in it it has a link to the sine wave, this isn't the one I saw at the time but very similar;

1400 watt semi sine wave inverter

Direct link to image of semi sine wave form for 1400 watt inverter

Forgot to mention, I did have to disconnect this inverter for equalizing, the batteries were fairly new at the time and I didn't think about the cheap inverter which switched off and beeped, I don't recall if I switched it off at that time or if I checked to see if it would just reset afterward.

I believe Homepower did an article last year and gave these inverters their own catagory. Perhaps someone could check, I don't have all the issues.

icarus

Re: Running Sanyo mini-split on MSW inverter?

Personally, I don't think I would put the fairly expensive mini-split at risk for the sake of a cheap msw inverter.

Tony

BB.

Re: Running Sanyo mini-split on MSW inverter?

XRinger wrote: »

BUT, If there weren't any transformers or AC motors at all, and the system converted all AC to DC using diodes,
what else could cause problems?

There are several ways of converting the 120 VAC into the high voltage DC used by power supplies/inverter/Variable Frequency Devices... Some are very sensitive to the square wave (0 volts to ~150 VAC) which can cause excessive current flow through rectifiers/filter or blocking capacitors.

In general, those systems with Active PFC (active or full electronic power factor correction) should be OK with MSW (although, there was one report here of what seemed to be a failure of a Active PFC on a MSW--as I recall).

Right now, I'm using unstable grid power that has a tendency to climb up around 250-256 vac.
My TED alarm could not be used at 140 vac, it kept going off at random times. (power spikes maybe)?
Setting the trip-point for 199 vac seems to have cured the problem.
This summer, they will actually turn UP the voltage for summer AC use.

I am a bit confused here... You are talking about a 120/240 VAC North American power drop?

If so, 256 VAC for Line to Line is high, but OK (264 VAC is usually "maximum").

The 140 VAC line to Neutral (?) could indicate a problem with your neutral circuit... Could be a bad/corroded neutral connection somewhere or undersized neutral return wire (too much voltage drop) powering a very heavy 120 VAC load (such as large motor starting current).

-Bill

LucMan

Re: Running Sanyo mini-split on MSW inverter?

XRinger wrote: »

Since the Sanyo I have using is using 'inverter technology'..

I'm wondering if other Sanyo owners here have used MSW inverters to supply their Sanyo mini-spit, or other brand mini-split AC/heatpump??

I'm thinking of getting one of the low cost 'StackAble' 2500 watt MSW units off Ebay. (48vdc to 230vac model).

Thanks,
Rich

Call Sanyo and ask someone in the engineering dept.

The Fujitsu units use DC fan motors and have an active filter module.

XRinger

Re: Running Sanyo mini-split on MSW inverter?

BB. wrote: »

There are several ways of converting the 120 VAC into the high voltage DC used by power supplies/inverter/Variable Frequency Devices... Some are very sensitive to the square wave (0 volts to ~150 VAC) which can cause excessive current flow through rectifiers/filter or blocking capacitors.

In general, those systems with Active PFC (active or full electronic power factor correction) should be OK with MSW (although, there was one report here of what seemed to be a failure of a Active PFC on a MSW--as I recall).


I am a bit confused here... You are talking about a 120/240 VAC North American power drop?

If so, 256 VAC for Line to Line is high, but OK (264 VAC is usually "maximum").

The 140 VAC line to Neutral (?) could indicate a problem with your neutral circuit... Could be a bad/corroded neutral connection somewhere or undersized neutral return wire (too much voltage drop) powering a very heavy 120 VAC load (such as large motor starting current).

-Bill

This model Sanyo has been around for 4+ years. My guess is, it does not have a lot of fancy electronics in it's power supply.
I'm betting it's just got some big diodes and caps.
My guess is that it's controller doesn't have any kind of line-voltage
(or DCV) feedback and just assumes it's between 187 & 253 vac. (~220).
And, the controller is sending DC pulses to the motors, assuming they are
within the normal range. (But the DC is actually unusually high).
I have a spare board on the busted unit in the garage, I'll pull it out and
check for transformers etc when it's warmer.

Mucho Volts! Yeah, North of Boston MA.. That's after the power company (NStar) turned it down too.
It was running high almost all the time before. Now we see the peaks mostly in the early mornings.
The Sanyo isn't rated for real high voltage.
http://i46.photobucket.com/albums/f147/Xringer/NCL/poweruse.jpg
(187-253).

I don't think there is problem with the wiring (or the neutral), I think the
TED was just triggering on random spikes coming down the line.
Over-all, it's nice to be able to see 120 vac on the line now.
Whereas before it was typically 126-127..
I have looked at the line on my O-scope, it's not too bad looking.

That's NStar on the left. My sig-gen is on the right.

XRinger

Re: Running Sanyo mini-split on MSW inverter?

Photowhit wrote: »

OK I found the link to a PDF of the 1400 watt inverter, with in it it has a link to the sine wave, this isn't the one I saw at the time but very similar;

1400 watt semi sine wave inverter

Direct link to image of semi sine wave form for 1400 watt inverter

Forgot to mention, I did have to disconnect this inverter for equalizing, the batteries were fairly new at the time and I didn't think about the cheap inverter which switched off and beeped, I don't recall if I switched it off at that time or if I checked to see if it would just reset afterward.

I believe Homepower did an article last year and gave these inverters their own catagory. Perhaps someone could check, I don't have all the issues.

Thanks for the pdf. I have heard of the over-voltage kicking in when the charger was putting out a lot of voltage. (Equalizing).
I have a 2.5-5kw model for 48vdc, but it's a 120vac out, so it's no good for my 220vac Sanyo.

I've looked at the wave form, and found it's not really the Semi-sine-wave
that I expected. Prehaps I didn't have the right amount of load.?.
Or, the right amount of reactance in the load..

It's good to hear you were able to run your regular AC using a stackable.
I've found that mine works pretty well on my stuff.
But can make a small transformers hum. I have three sump pump controllers with transformers in them.
They make low voltage DC for the little PCB and it's water level sensor unit.
Anyways, one of the transformers sings and the other two are quite.

They all work fine and the pumps seem fine during the testing done (during the last flood).

techntrek

Re: Running Sanyo mini-split on MSW inverter?

What about using a voltage regulator, or double-conversion UPS? Using the later you could even specify an output of 220 volts instead of 240. I have one that has 6 or 7 possible output combinations.

XRinger

Re: Running Sanyo mini-split on MSW inverter?

LucMan wrote: »

Call Sanyo and ask someone in the engineering dept.

The Fujitsu units use DC fan motors and have an active filter module.

I worked in the engineering dept at NEC (Nippon Electric Corp) for 18 years.
If someone had called me (or any of the other engineers) and asked
if they could using a MSW on their NEC PC or printer,
guess what I would have said..?. (Right off the top of my head).?.
I already know what the Engineers in Japan would say..

What I'm looking for here, is someone who has already used a MSW inverter
with an 'inverter' type ductless mini-split.. A voice of experience.

XRinger

Re: Running Sanyo mini-split on MSW inverter?

icarus wrote: »

Personally, I don't think I would put the fairly expensive mini-split at risk for the sake of a cheap msw inverter.

Tony

When I see something like this,

http://www.solarpanelsplus.com/dc-air-conditioning/

"* No Inverter - 100% DC operation"

I have to ask myself, how different is this design?
And could a standard inverter mini-split like mine, be converted to run off DC only?

If it was actually possible to run my Sanyo off 200 or 400 vdc,
then it shouldn't really matter if a standard unit was being fed MSWs..

Photowhit

Re: Running Sanyo mini-split on MSW inverter?

XRinger wrote: »

I've looked at the wave form, and found it's not really the Semi-sine-wave
that I expected. Prehaps I didn't have the right amount of load.?.
Or, the right amount of reactance in the load..

I'm not sure if there was anything in the PDF, but I recall in it's low standby like more it has less steps, more of a MSW.

XRinger

Re: Running Sanyo mini-split on MSW inverter?

techntrek wrote: »

What about using a voltage regulator, or double-conversion UPS? Using the later you could even specify an output of 220 volts instead of 240. I have one that has 6 or 7 possible output combinations.

I'm not too worried about the high voltage or the crazy power surges anymore.
I think that I've got that under control now.
http://ecorenovator.org/forum/geothermal/683-sanyo-24khs72-ac-hp-diy-install-project-36.html#post12588


The reason I want to see if anyone has successfully used a cheap ($200?)
MSW inverter with an inverter type mini-split, is because I have a 500w
PV array on a tracker, feeding a 48v bank, that needs a dump load..

When it's nice and sunny, the bank goes into float pretty quickly.
It's a backup system and I think it could use a little daily workout.
So, since the Sanyo typically sucks down 400-500 watts, why not
feed it the leftovers?

LucMan

Re: Running Sanyo mini-split on MSW inverter?

Fujitsu calls their power supply simulated 3 phase ( pulse DC). The compressor runs on 350-400 vdc
The Power factor is 1,

XRinger

Re: Running Sanyo mini-split on MSW inverter?

I was doing some reading here:
http://www.electronicspoint.com/tecumsehs-line-compressors-solar-power-air-conditioning-t222045.html

The poster 'John' seems to have got his hands on a mini-split manual
and confirmed the Klimaire model he was looking to buy, is a pure DC machine.
All the AC coming in, is rectified into DC before use..

For some reason, he wants to mod his inverter and the mini-split, so the
HV DC inverter voltage can be fed directly into the DC filter of the mini-split.

I don't like the idea of hacking into my MSW inverter or my Sanyo,
because of the loss of compatibility with regular AC appliances.

I'm still looking for anyone who has run a mini-split off a MSW inverter,
or even a gasoline generator..

Thanks,
Rich

waynefromnscanada

Re: Running Sanyo mini-split on MSW inverter?

Methinks you're on your own with this one. I do not believe you will find anyone on this form who would try such a thing on such a nice mini-split unless it was owned by someone they didn't exactly care for.:p

XRinger

Re: Running Sanyo mini-split on MSW inverter?

waynefromnscanada wrote: »

Methinks you're on your own with this one. I do not believe you will find anyone on this form who would try such a thing on such a nice mini-split unless it was owned by someone they didn't exactly care for.:p

Did you see the DC-Only Mini-Split picture above?
That design seems to point towards the fact that DC only is possible..

If there are no transformers or any devices that actually require the power to be in 50-60hz AC format,
then I'm gonna conclude that a transformerless machine could run on DC only.

Chopper (or inverter) power supplies have been around for decades.
Like this one.. http://www.freepatentsonline.com/6587358-0-large.jpg
Their key design feature is the AC input. No heavy (expensive) transformer.
A lightweight (cheap) high frequency transformer is used instead.
50-60 Hz isn't even required on the input.

I'll bet many of these power supplies could run off plain old DC..

Anyways, if it's true that some devices don't really need 60hz AC,
then why would those devices need a clean sine wave??
(To convert directly into DC)..

BB.

Re: Running Sanyo mini-split on MSW inverter?

The AC / DC / Voltage issue is based on the type of front end of the "power supply" section of the "devices"...

For old electronic power supplies... They had a 120 / 240 VAC selection switch. All they did was use a rectifier front end (with voltage doubler at 120 VAC) for a ~340 VDC intermediate voltage... So you could feed ~340 VDC into those supplies and they would work OK.

For newer active PF Corrected Power Supplies, they will actually run very happily on ~108 to 264 VDC or ~50-60 Hz.

And you sometimes, for small supplies, they simply use a diode and capacitor shunt regulator that only lets a small amount of AC current through (blocking cap) to supply a very small amount of power for local use (Kill-a-Watt, Christmas Tree Lights, etc.).

The old power supplies, you hit them with a "square wave" and they could have very high "peak currents" and overheat from I^2*R resistance heating.

For (most/all?) Active PF Corrected Supplies, they control their input current electronically, so they don't care about the front edge of a "square wave" and will not draw excessive current.

For capacitor blocking type small/cheap supplies, the square wave / non-sine wave input voltage has a bunch of high frequency energy which the capacitor is more than happy to let through--This overwhelms the shunt regulator and causes internal DC over voltage and/or I^2*R overheating.

My past recommendation was to take a Kill-a-Watt or a good quality Current Meter / Current Clamp and measure the DC current on the input to a the load in question.

If on utility power, you had a PF of ~0.95 or better (near 1.0)--There was a good chance it would operate correctly on a MSW inverter (power factor corrected AC induction motors that a PFC capacitors excluded). Also, it had to be rated for ~110-240 VAC with no 120/240 switch or "auto voltage detect" circuitry and not rated for 110 or 220 VAC (this would be a "wide range" active PFC circuit which would should run fine on MSW power).

Then connect the load in question on a MSW inverter... If the VA does not fall under 0.95 -- Then the device should run fine on MSW inverters (or the Amperage draw does not go up when placed on MSW).

I used to be 100% sure that the above was a good way to find out if your load was compatible with MSW.

However, somebody reported that they had a load with PFC that failed on their MSW inverter (I don't remember the details, and the failure coul have been some other reason--no failure analysis was done, so as I recall, we could not know the MSW was responsible).

So, I am only 80% sure that the above testing would validate operation on a MSW inverter...

There are also sometimes little "gotcha" things with devices on MSW... For example a PFC 120 VAC PFC=0.95 will run just fine on MSW, but the internal timer/clock does not work correctly (may run up to 2x as fast on a MSW inverter) because they look for 60Hz timing from the input AC sine wave.

If the device is rated 110-240 VAC 50/60 Hz, it probably has its own internal timing crystal and does not use the AC mains for signaling.

-Bill

XRinger

Re: Running Sanyo mini-split on MSW inverter?

Thanks for the interesting post!

The rated PF isn't too bad.. 95% for cooling and 90% for heating.

The power use is about the same in both modes, I can't see why the PF would change to 90% for heating.

I've been looking for a schematic, no joy so far.

Photos from a Sanyo training PDF shows some main boards and the indoor boards and each has a small transformer.
It's hard to judge from appearance, but they might be high-frequency transformers, making low-voltage for the DC logic needs.
I'll ohm them out this spring when try to locate the leak in the 'spare' outdoor unit.
The controller chips all have at least one crystal for their timing.
The RTC in this system is in the handheld remote/thermostat.

LucMan

Re: Running Sanyo mini-split on MSW inverter?

XRinger wrote: »

I was doing some reading here:
http://www.electronicspoint.com/tecumsehs-line-compressors-solar-power-air-conditioning-t222045.html

The poster 'John' seems to have got his hands on a mini-split manual
and confirmed the Klimaire model he was looking to buy, is a pure DC machine.
All the AC coming in, is rectified into DC before use..

For some reason, he wants to mod his inverter and the mini-split, so the
HV DC inverter voltage can be fed directly into the DC filter of the mini-split.

I don't like the idea of hacking into my MSW inverter or my Sanyo,
because of the loss of compatibility with regular AC appliances.

I'm still looking for anyone who has run a mini-split off a MSW inverter,
or even a gasoline generator..

Thanks,
Rich

As I stated in the previous post the DC is pulse DC. The DC is pulsed to 3 sets of windings alternately at a frequency of 20 to 120 hz depending on the capacity of the system. So I don't think putting straight DC to the compressor will work.

XRinger

Re: Running Sanyo mini-split on MSW inverter?

LucMan wrote: »

As I stated in the previous post the DC is pulse DC. The DC is pulsed to 3 sets of windings alternately at a frequency of 20 to 120 hz depending on the capacity of the system. So I don't think putting straight DC to the compressor will work.

I'm positive it won't work.
I don't think anyone is talking about bypassing the motor control circuits.

The Klimaire hack was described as taking some high voltage DC from
a power inverter and inserting it into the Klimaire power supply, bypassing the rectifiers.

I guess the idea is to bypass the AC output transistor switches in the inverter.

Back on the real topic, "Running Sanyo mini-split on MSW inverter?",
is asking if a Mini-split can run on a MSW power source.?.
My point in talking about the Klimaire hack, was to point out the fact
it seems to be able to run on plain old DC power.

That means there are no 50-60Hz AC motors or transformers that need sine waves..

So, if it the Klimaire can run off DC power, why couldn't it also use MSW?
Would there be any bad side affects to the input diodes while converting
the ugly MSW power into DC??

BB.

Re: Running Sanyo mini-split on MSW inverter?

XRinger wrote: »

The Klimaire hack was described as taking some high voltage DC from a power inverter and inserting it into the Klimaire power supply, bypassing the rectifiers.

Depending on how Klimaire designed the AC power front end--They may not even need to bypass the rectifiers... Just feed the appropriate DC voltage right in through the front end.

I guess the idea is to bypass the AC output transistor switches in the inverter.

Hmmm. If you are talking about a MSW/TSW 48 VDC to 120/240 VAC inverter? I don't think they work this way... They need to AC transformer/inductors to up convert the voltages. There is no DC intermediate output stage (I think, there is a lot of different product out there and it is very possible that somebody has done it different).

So, if it the Klimaire can run off DC power, why couldn't it also use MSW?
Would there be any bad side affects to the input diodes while converting
the ugly MSW power into DC??

If the Klimaire had Active PFC--Probably, no problem at all.

If the Klimaire has a simple voltage rectifier/cap front end--Two possible problems--High edge rate of MSW I squared R overheats the diodes/HV caps, and/or the unit overheats from MSW having too low of input peak voltage... TSW sine wave inverter have higher peak voltages and charge the intermediate HV caps to a higher voltage than MSW would.

Lots of variables and I am not smart enough to look at the front end to determine how a particular one works.

-Bill

XRinger

Re: Running Sanyo mini-split on MSW inverter?

I didn't see if 'John' specified the type of inverter he was going to hack.
If it was a true sine wave, it's possible he could have some power savings.
(I'm not going to dwell on it, because I'm not hacking my stuff).


My guess for the Sanyo is, "simple voltage rectifier/cap front end". Since the USA seems
to be a few years behind in this area. (They send us the older tech stuff).
But, I think there may be some series inductance, to filter spikes from the grid.
(That's where some of the 95-90% PF comes from).

I worried about the fast rise time too. But, it seems like the first pulses would
charge up the filter caps. The PS is designed to run at 2.5kw,
so I'm not too worried about really large current spikes while running under 500w (2A)..
I figure it stays well under 700w about 95% of the time.
In a nutshell, a light load is not going to be extra hard on the input components, even with fast rise times.

The inductive part might be on L1 & L2 off the main board..?.
I wonder what those jumpers on the top do? AC & DC test break-outs?

Blackcherry04

Re: Running Sanyo mini-split on MSW inverter?

I'll throw my $.02 in here. I have no idea if a Sanyo mini-split would or wouldn't, but I know that the most of the new energy efficient refrigerators that have a digital control board won't, or at least not very long. Thats not to say some won't.

Most all the Inverters in the Marine world are Heart / Trace / Xantrex Freedom MSW series. I know plenty that have tried to up-date their refrigerators with new models and they won't run on MSW. All the old analog ones would even if they were noisy and ran hotter. I know some that have been on MSW for 20 years.

It always seemed to me that anything with a timing circuit had a issue with MSW. Some smaller A/C's will as long as the thermostats are compatible.

XRinger

Re: Running Sanyo mini-split on MSW inverter?

We have a new (small) freezer down in the basement, it's on the same backed-up 120ac loop with 2 of the sump pumps.
I looked at the diagram on the label, and there is nothing modern in there at all..
On grid, or on MSW , it buzzes the same way and doesn't heat up at all.

Maybe if I ran it on MSW all the time, it might shorten it's life.?.

Blackcherry04

Re: Running Sanyo mini-split on MSW inverter?

XRinger wrote: »

We have a new (small) freezer down in the basement, it's on the same backed-up 120ac loop with 2 of the sump pumps.
I looked at the diagram on the label, and there is nothing modern in there at all..
On grid, or on MSW , it buzzes the same way and doesn't heat up at all.

Maybe if I ran it on MSW all the time, it might shorten it's life.?.

I said " Hotter ", I'll correct that and say not as " Efficient ". I notice when I leave Shore power that the ice maker is slower and we have to turn the setting down a notch so the refrigerator section stays normal temperature . That said, in the summer away from the dock the interior of the boat is also warmer than when under cover in the slip. Overhead paddle fans is where you really notice the buzzing sound and they turn noticeably slower on MSW. Microwaves seem to work ok as far as the output, the timers will not always work correctly. Some clocks will be very erratic.

JESSICA

Re: Running Sanyo mini-split on MSW inverter?

icarus wrote: »

Personally, I don't think I would put the fairly expensive mini-split at risk for the sake of a cheap msw inverter.

Tony

When I read this post, I concluded it was sound advise; hence, I do not power my Sanyo with my “cheap” msw inverter (though I don’t think it is “cheap” in any way).

Nevertheless, another question came recently to my mind:

Early in the morning, before I go to work, I turn the Grid off and switch on my small pv system. Since only the fridge and a small radio remain on, my batteries are in “float” almost all day long, and lots of energy goes to waste. My Sanyo remains completely disconnected from all power. So my question is:

Would it be safe to keep it connected (powered) to my msw inverter, until I came home around 5:00 PM, and then switch back to the Grid and turn the unit on? This way, I guess, the unit will be ready to work, just in case it is actually necessary to plug the unit for one or two hours before turning it on.

P.S.: My little knowledge of English may make it hard to understand my question. So, what I am trying to ask is this: Will it be safe to just power the Sanyo with the msw for 8 hours without turning the unit on?

Thanks

BB.

Re: Running Sanyo mini-split on MSW inverter?

It is risky... Your A/C has electronics in them that require electrical power to run.

Many of the smaller electronic power supplies and small transformers are exactly the ones that overheat when operated on MSW type inverters.

The heater in the motor/pump itself will probably not be damaged by the MSW inverter. But the electronic controls certainly have that risk.

One thing to try--if you can plug your Sanyo into a Kill-a-Watt meter and look at the Power Factor reading when the A/C is "off".

If the PF is greater than 0.90 or so--It may be OK to try on MSW.

If the PF is less than 0.80 or so--then there is a good chance it will be damaged by running on a MSW inverter.

You can try the above measurements both on Grid Power and MSW power... If the PF is "bad" (less than 0.90) on MSW--I would not recommend risking it.

Basically, PF=1.0 -- The unit is using "AC" power "efficiently".

PF<0.80, the unit is pulling "extra current" through capacitors, inductors, and/or diodes in an "inefficient manner". That extra current may create more heat inside the electronics and can cause them to fail.

If you have any "timer" settings/operations inside the Sanyo--they may be "confused" by the MSW wave form.

-Bill

XRinger

Re: Running Sanyo mini-split on MSW inverter?

I got a look at the (spare) Sanyo outdoor unit the other day.



Found a very small transformer (lower right of middle) that has one side
(primary I think) connected from "AC2", which is also common to a five relay
array that drives the 'Heater1' relay and what might be a Defrost relay.

Anyways, I could not 'see' the transformer under the PC board.
But, I could reach under the PCB and touch the transformer.
It feels like it's about 12mm x 12mm in size. Which makes me think it's
putting out a very small amount of power.

My guess is, the transformer is so small, it could not be used to power all
the low voltage analog & digital circuitry on this large PCB.
I think, it might be used to sample the AC line. In case of grid failure,
the missing AC cycles would cause the Sanyo to gracefully power down,
using the last bit of power left in the input capacitors.

~~~~

I know that MSW power has been used on all sorts of small transformers,
in laser printers and PC power supplies. I have not heard of any that were damaged.
The main warning that I'm seeing a lot is about large AC motors, running hot.

IMHO, my little Sanyo PCB transformer would not heat up enough to cause it any damage,
unless it already running right at or over it's maximum power rating.


Around the house, I'm detecting some hum from small transformers in my loads, but no excess heating.

So, I think the chances for using MSW power in my Sanyo are very good.

I still need to look at the PCB of the indoor unit. If it's transformer is also
very tiny, then MSW should work fine on the Sanyo..