Micro Air

[StirCrazy]

Hi, just looking for input from people that have them on their effectiveness. I am thinking of getting a portable genny for the 5th wheel for those times that I need an AC and don't have power. I have a 15000BTU dometic AC, and I must figure out what size genny I need also.

As some of you know I personally hate the noise they make, so it must be quiet and really won't be used for anything else as my solar can do everything else. the other issue I have is there has only been 4 days in the last 5 years of camping where I needed an AC when I was boondocking, so I am really torn weather I need a genny or just see what it would take to be able to run on solar, but I think it's too tall of an order for solar.

[Itinerant1]

MNRon wrote:
Cptnvideo - as 3Tons said, better than I did, my Magnum sees the genny as a defective power source because of the milliseconds of voltage droop when it becomes loaded. I have started the ACs on batteries and hoped the genny would take over. Unfortunately the Magnum takes a few second ms to qualify the new source, then when it tries to bring it in the genny voltage drops instantaneously and the Magnum kicks it out. If I run into this next time I might try limiting genny power to 15A, or 10A etc to see if that allows it to provide most of the power without significantly dropping. We’ll see.

3Tons - thanks, I’ve thought about just putting a Magnum bypass in to allow direct running of AC from genny. I think your solution is more elegant. Still I haven’t given up with futzing with current hardware instead of adding more…. Frankly not sure if I had spent more on a Honda I might not have been aware of this idiosyncrasy. Not sure if I’ll keep messing around or maybe make a hardware change…

I set my incoming to 18a when using my eu2200i generator and have no problem using it when needed for long run air conditioner time, I do not set it to eco mode on the generator. If you're getting the fault light and it's kicking your generator off try running just your fan on the ac unit for a minute or 2 then turn it over to air conditioner.

2 years ago when I was in SD and couldn't leave we had a hot spell that I would run the air conditioner off of solar/ batteries starting around 10am for 2-3 hours when the batteries got down to a SOC of 40% range I would switch over to the eu2200i generator. It will run for 4 hours + on a tank running the air conditioner. During that time the batteries would get fully charged at some point dependingon the sun. Once the batteries were fully charged by solar I would turn off the generator and run the air conditioner from solar/ batteries again for another 3-4 hours. By then it was getting cooler outside and air conditioner wasn't needed. This was a 2 week event off and on.

Most the time now were just using solar/ batteries and if it gets that hot we run to somewhere cooler if possible or just do what I posted above.

I'm over 7 years now on my setup with lfp batteries living fulltime off of them boondocking all of it mostly. Nov 4th or 5th of 2021 was the last time we were hooked to a power pole for a couple days traveling. Just amazing the punishment these lfp batteries can take.

Edit: I should note that I turn the charger off on the me-arc while using the generator for the air conditioner. Any charging of the batteries is coming from solar that isn't being used in load support. Also the front compartment is opened for fresh air because long heavy load runs will produce some heat from the inverter, you don't want to add the extra heat to the batteries if they're in the same area. I'll see cell temps rise to 93-95f and settle back to low 80s depending on the ambient temps for the evening.

My Me-Arc settings for the system....

Favorites (can be changed to personal taste)
F1_ Bat amps - PT ADC (present be produced)
F2_ AC output - 121 VAC/ 60.0 HZ
F3_ AC input - Amps= 15a (adjustable with incoming power)
F4_ Load amps - 0 amps AC
F5_ AC Amps - -2 amps

CRTL
01_ AC in Control - Auto Connect
02_ CHG Control - Multi Stage
03_ Gen Control - Off
04_ PT Control
• a_ PT Chg CTRL 1 - Multi Stage
• b_ PT Aux Relay - Control= Disengage
• c_ PT Alarm - Control= Off
• d_ PT Mppt Ctrl - 15 min sweep

METER
Inverting_ DC (present time reading)

01 DC Meters
• a_ DC volts (present time reading)
• b_ DC amps (present time reading)
02 AC Meters
• a_ AC output (present time reading)
• b_ Load amps (present time reading)
• c_ Input AC (present time reading)
• d_ Inv/ Chg amps (present time reading)
• e_ Input AC1 (present time reading)

SET UP
01 System Set up
• a_ Set Clock
• b_ Screen set up (press select) _ Brightness (50%), Contrast (100%), Power save (1 min)
• c_ Temp select - Fahrenheit
• d_ Max charge- Amps 200 adc
• e _ Link PT Chg - setting - yes

02 Inverting/ Inverter set up
• a_ Search watts - Off
• b_ LBCO setting - 12.0 vdc
• c_ AC In time - 6:00am-6:00pm
• d_ AC In VDC - 11.O-14.1 vdc
• e_ AC In SOC - 80%-100% SOC
• f_ Power up - Always off

SET UP INVERTING
03 Charger Set up
• a_ AC Input - Amp= (can be set to available shore power/ generator incoming power)
• b_ VAC Drop out - 80 VAC
• c_ Battery type - Custom (with in here absorb voltage can be adjusted)
• d_ Absorb done - Time= 0.1 hrs (minimum, can't be turned off)
• e_ Max charge - Rate= 100%
• f_ Max charge - Time= 12.0 hrs
• g_ Final charge - Stage= Multi
• h_ EQ Reminder - Days= Off

04 AGS SET UP - No AGS Present
05 BMK SET UP - No BMK Present

06 PT SET UP (Magnum pt controller follows Magnum inverter settings)
• a_ Battery Type - Linked
• b_ Absorb Done - Linked
• c_ Maxed Charge - Rate= 100%
• d_ Max Charge - Time= 12.0 hrs
• e_ Bulk Start (press select)
- select Bulk Start, Daily / sun up= yes
- set Bulk Start, Volts= 12.0
- set Bulk Start, SOC= 80%
• f _ PT Aux Relay - 10.0 to 14.0
• g_ PT Alarm - 10.0 to 14.0
• h_ Power Save PT - Display= 15 min

TECH
01 Temperatures (press select_ scroll)
- Inv BTS (present time reading)
- Inv TFMER (present time reading)
- Inv FET'S (present time reading)
- AGS Sensor 0ff
- ACLD Temp 32f
- PT BTS (present time reading)
- PT Inductor (present time reading)

02 Versions (press select_ scroll)
- Inverter: 1.2
- Remote: 4.0
- AGS: 0.0
- Router: 0.0
- ACLD: 0.0
- PT: 1.1

03 Inv Model - MSH3012H (3000w hybrid)
04 Fault History
05 Set up pin
06 Ext Control - No ext control
07 Show all - Menus= No
08 Load Defaults

The following parameters are for programming the ME-ARC Version 4 advanced control.

Setup 02B LBCO Setting: Volts = 12.0v
Setup 03C Battery Type: = Custom
Set Absorb Volts: = 14.1v
Set Float Volts: = 13.6v
Set EQ Volts: = 14.1v
Set EQ Done Time: = 0.1
Setup 03D Absorb Done Time: = 0.1 (minimum)
Setup 03E Max Charge Rate: = 100%
Setup 03G Final Charge Stage: = Float

[3_tons]

MNRon said:

“3Tons - thanks, I’ve thought about just putting a Magnum bypass in to allow direct running of AC from genny. I think your solution is more elegant. Still I haven’t given up with futzing with current hardware instead of adding more…. Frankly not sure if I had spent more on a Honda I might not have been aware of this idiosyncrasy. Not sure if I’ll keep messing around or maybe make a hardware change… “

****************

Well, my Xantrex pass-thru ProSine is truly ‘chock full’ of programmability, and I tried every about program work-around I could think of - that’s when I decided to try a autoformer (between the genny and inverter), but once the air conditioner got warmed-up (say after 20 min or so…) the autoformer made no difference…

It was a most perplexing matter (ugg…), one which only happened when attempting to run the genny in the more desirable, quieter, but somewhat sluggish ‘eco mode’…Then by happenstance it finally occurred to me that the inverter might just be ‘doing it’s job’ as a incoming power sentry, and all along, this had been the actual root cause of the maddening inverter in & out again cycling…

From my way too many exhaustive hours of non-productive frustration, programming bandaids wouldn’t work - I very much doubt that there’s a ‘more appropriate’ fix than to simply bypass the inverter…JMHO

3 tons

[Cptnvideo]

Don, Ron,, 3tons,
I have Victron mppt, but sadly GoPower 3kw inverter/charger. I say sadly because it only monitors and controls Line 1 for load sharing. I can work around the shortcoming with my EMS and a little math. But I don't really need the load sharing as I can run any of my 3 ACs with solar & battery.
PS. We try not to camp where the ambient temperature would necessitate all day AC.

[MNRon]

Cptnvideo - as 3Tons said, better than I did, my Magnum sees the genny as a defective power source because of the milliseconds of voltage droop when it becomes loaded. I have started the ACs on batteries and hoped the genny would take over. Unfortunately the Magnum takes a few second ms to qualify the new source, then when it tries to bring it in the genny voltage drops instantaneously and the Magnum kicks it out. If I run into this next time I might try limiting genny power to 15A, or 10A etc to see if that allows it to provide most of the power without significantly dropping. We’ll see.

3Tons - thanks, I’ve thought about just putting a Magnum bypass in to allow direct running of AC from genny. I think your solution is more elegant. Still I haven’t given up with futzing with current hardware instead of adding more…. Frankly not sure if I had spent more on a Honda I might not have been aware of this idiosyncrasy. Not sure if I’ll keep messing around or maybe make a hardware change…

[pianotuna]

Cptnvideo and MN Ron,

Tech support told me they do NOT recommend running an air conditioner from the Magnum 3012.

Others reported good success using a Victron inverter/charger.

I saw little if any difference after getting the MicroAir.

I did one quite short test with the Magnum on load support with generator and autoformer. I may have been unfair because I had limited generator input to 23 amps. The test showed no significant improvement. I've not been where I would wish to run the air conditioner since that time (covid rules us, unfortunately).

[3_tons]

MNRon said:

“ All of that background is to provide my experience with Westinghouse/Magnum (in)compatibility and to ask if you have other thoughts on my experience. I suspect Honda does much better with surge droop so you may never have seen this. Thoughts?…”

************
I had the same nagging problem when trying to run the air conditioner (with MicroAir) from a portable generator (while in ‘eco mode’), while using a pass-thru inverter and 400a/h of lithium batteries…

After a whole bunch of time consuming test-trials (including trying an Autoformer to little if any avail…), it turned out that the inverter was seeing the generator (only while in eco mode) as a defective power source and continually taking over the full load…

Ultimately (ugg!), the real solution was to simply bypass the finicky inverter by adding another ATS switch just ahead of the air conditioner with it’s own dedicated plug-in generator power cord…In this way, the inverter can continue to be used, independent of the air conditioner or generator, and were the generator to suddenly quit running, the inverter (if in standby…) would (via this ATS Switch) simply take over the air conditioning load without any sinusoidal conflicts…

Hope this helps,

3 tons

[Cptnvideo]

MN Ron, could you start up A/C on batteries only, then turn on genny?
Or does your inverter have a load sharing feature to make the batteries take the excess current?

[MNRon]

Itinerant1 - great 4/15 post.

I have a similar setup and fought to runAC without MicroAire when hot, especially at any altitude; and still am not confident in the Westinghouse genny/Magnum inverter relationship . My setup: 540AHr BB, Magnum3k Boost inverter, Westinghouse i4500 genny, MicroAire on both ACs.

Prior to installing soft starts the Magnum voltage monitor circuitry would detect too much drop from the genny when starting and kick the genny out: if in pass through just starting a new ‘hook up’ loop and not passing voltage through; if in boost it would then run AC solely off of battery. After spending lots of time with Magnum tech support I’ve got VAC dropout as low as it goes (60VAC) but wish Magnum was more tolerant of the droop, or had a setting to accommodate it.

Even after adding soft starts I had some issue a few weeks ago with genny/inverter compatibility that I didn’t fully resolve.

I have run AC on just the BBs, but when drawing ~150A for extended periods circuits heat up more than I’m comfortable with and IR drop within BBs along with 4/0 wiring starts to bring voltages down below 13.0 pretty quickly and trending below 12.0 where some cutoffs come into play.

All of that background is to provide my experience with Westinghouse/Magnum (in)compatibility and to ask if you have other thoughts on my experience. I suspect Honda does much better with surge droop so you may never have seen this. Thoughts?

[Cptnvideo]

StirCrazy,
Its a mild day here in NW Arizona and it's 12:49 MST. SOC got to 97%, so I decided to turn on A/C to keep solar in bulk charge. Solar is putting out 1245 watts, 90.2 amps and 18.7 amps being drawn from batteries. Res fridge, TV is on.
I'm running the soft start unit but the only difference I see between it and the other 2 is the Dish receiver goes into restart when either of the other 2 start.

[pianotuna]

ktmrfs thanks for the excellent explanation.

I do have one location which I visit yearly where the unloaded line voltage is 100. The autoformer is a god send then to boost the voltage when running an electric heater.

[ktmrfs]

micro air vs. autotransformer:

the purpose of the micro air is to reduce PEAK starting current (locked rotor amps) so that non ideal voltage sources (typical small generator) that have limited max current output to START a AC unit. It does nothing to increase voltage once started.

Autotransformer:
bump up a low voltage source to a higher voltage to keep voltage within expected operating range.

So. If your using a "ideal" voltage source, most utility lines that can easily supply 3x or more the breaker rated current on a short term basis, the micro air really isn't needed.

But if your line voltage sags, then the autotransformer is solution.

Now I suspect, but can't verify, that what pianotuner is seeing with the micro air and autotransformer is this, The auto transformer probably has hysteresis, it will cut in at a low voltage and KEEP it in at a given level EVEN if the input voltage rises somewhat above the cut in voltage. So what may be happening is w/o the micro air, voltage sags enough to cut in the autotransformer but it doesn't rise enough to cut it out completely and continues to do it's intended job,

Now add the micro air, Now input voltage never drops enough to get the autotransformer to cut in, since the current draw is low enough to not cause a big enough sag in input voltage, so the voltage remains at the very low end,

so.... in this case the micro air (a) isn't needed to start the AC anyway and (b) then voltage remains low,

If one takes the autotransformer out of the circuit and starts the AC I suspect the line voltage then would be back to the 107 or whatever it is with the micro air, Micro air shouldn't reduce the input current draw once the compressor is running by any noticeable amount, it only reduces starting current,

[StirCrazy]

K_and_I wrote:
This is not directly related to rv's, but I had an Easy Start on my trailer and liked it so well, I put one on my residential 2.5 ton heat pump when Micro Air started making residential units. My heat pump compressor was rated at 73 amps lra. The Easy Start has blue tooth ability to be read by my phone. This is what it showed after the 5 training starts:



From 73 lra to 23- not bad

wow, I am going to have to check that out. would be a lot easier on the breaker over a longer period also

[3_tons]

Thanks, From 73 LRA (Locked Rotor Amps) down to 23 LRA (about a 2/3rds reduction!) is all that’s needed to know…Voltage sag is of little concern…

3 tons

[pianotuna]

K_and_I,

Nice that they have a blue tooth app. Mine does not as I was an early adopter.

[K_and_I]

This is not directly related to rv's, but I had an Easy Start on my trailer and liked it so well, I put one on my residential 2.5 ton heat pump when Micro Air started making residential units. My heat pump compressor was rated at 73 amps lra. The Easy Start has blue tooth ability to be read by my phone. This is what it showed after the 5 training starts:



From 73 lra to 23- not bad