Victron Multiplus Will Not Run Air Conditioner

[howson]

I've ran the air conditioner many, many times on just the inverter without any issues--in fact I've run BOTH air conditioners in my 315RLTS without any issues off just the inverter. Suddenly (on the previous trip while stopped at a rest area) I noticed the Victron will not start either air conditioner.

Extensively troubleshot today trying to isolate the problem. Both air conditioners have EasyStarts installed. I looked at the bedroom (13.5K unit) a/c's EasyStart and trouble lights D22 and D23 were lit after the failed starting attempt. According to MicroAir's Advanced Troubleshooting info, that means there was a Short Cycle Timer (3-minute restart violation) or a Power Interruption.

I reset the EasyStart on the bedroom a/c and went through the re-learn process. No help. Same problem.

I then set the jumper in the Easy Start to defeat it (bypass the microprocessor control) and got the same result--a/c will not start on the inverter.

Watching the BMV-712 very closely there's a slight voltage drop when the compressor attempts to start, so it is trying to start but the Easy Start aborts due to what it sees as a "Power Interruption".

Both air conditioners start and run perfectly on shore power.

The microwave runs fine on just the inverter (pulling >1500W). In fact I ran the microwave and both air conditioner fans on high all at the same time, pulling >2700W out of the batteries through the inverter. No issues.

I removed the MPPT Solar Charger from the circuit and disconnected the Renogy DC-DC Charger from the inverter. (Very unlikely they'd be causing an issue but isolated them as a variable.)

Only items left that could be the single cause of the problem are AMSolar's Smart Phase Selector (SPS), the inverter, and the Battle Born Batteries.

I bypassed the SPS so the output of the inverter went straight into the trailer's Power Distribution Center (lower, or black, wire of the two 50A legs). The air conditioner still refused to work. It's not the SPS.

Checked and double-checked the inverter's configuration. I removed all the extra assistants (DVCC and ESS). I made sure the VE.bus was reset after the changes. I tried turning on the UPS function and turning it off. No matter what settings I tried in the inverter the a/c still refused to engage the compressor.

Finally, I ran the air conditioner on shore power (so the compressor was running) and then shut off shore power. In the past the a/c kept running on the inverter without a hint of an issue. Today the compressor immediately quit when shore power was lost (but the fan kept running).

At this point the only thing I can think of is my battery use is so out-of-the-norm that even though the Battle Borns are supposed to self-balance they currently are not balanced. When the compressor calls for the large start up surge (even the relatively mild settings of the Easy Start) the BMS is temporarily shutting down power for a split second. I'm guessing this is also true when switching from shore power to inverter power with a large load.

What I'm going to do is (almost) deplete the batteries and then recharge off of shore power back to 100%, allowing for a full absorption and then float mode without any interruption or secondary power input.

If anyone has any other ideas...please...fire away.

[TucsonJim]

Howard - One other option is to remove one Battle Born battery at a time from the circuit. If the problem corrects itself with one particular battery out of the circuit, you likely have a battery going bad and you'd need to contact BB for a replacement.

Jim

[ncitro]

Thorough troubleshooting, but if you tried killing power while it was running, and it still died, would it not indicate the problem is not with inrush? There should be no inrush in that case right? Or you think that even with the unit spun up and running, during the small amount of time it takes to switch from shore to inverter theres enough inrush there? I feel you though, not sure what else it could be. I guess the inverter itself? Strange way for it to fail though, if it can make enough power for the microwave. Probably not the AC unit since neither work, and they work fine on shore.

Out of curiosity have you ever tried either of them without the easy start on the inverter? Just curious if you would expect them to work with it disabled. Your gear should all be in warranty right? I know you did the project in phases. A call to AM Solar may be in order. (I assume you bought the Victron there).

[Guest]

It would not hurt to isolate each battery as Tucson has stated but also charge and balance each battery independently.

Jim

[howson]

TucsonJim , ncitro Guest

Thanks for the replies. Balancing the batteries separately is probably a good idea if the initial, do-them-all-at-once effort fails. (Pain to access and disconnect the batteries due to their location. Rob is going to think, "told 'ya to put separate shutoffs on the batteries but you didn't listen"! He's too polite to type it out...)

[Cate&Rob]

TucsonJim , ncitro Guest

(Pain to access and disconnect the batteries due to their location. Rob is going to think, "told 'ya to put separate shutoffs on the batteries but you didn't listen"

LOL! That thought did cross my mind .

Rob

[Retgw2]

I wish I had some words of wisdom given all the help you have been giving me with my own Inverter/Battleborn issues, but the only things that come to mind involve a possible loose DC connection that could have occurred during your recent trip. Since you microwave still operates you could possibly check for a voltage drop that is occurring between the batteries and inverter connections.

[howson]

I talked with Micro-Air today and was told both my Easy Starts require a firmware update. They could not explain why they worked previously and now do not, but they insisted the issue is firmware related. So the next step is to remove the Easy Starts and ship the units back to Micro-Air for the firmware update.

I had seen one reference to a firmware update on the Victron Community forum, but just one random reference with no further details or discussion.

I'll continue to update this thread with more info as I proceed to solve this puzzle.

[ncitro]

I talked with Micro-Air today and was told both my Easy Starts require a firmware update. They could not explain why they worked previously and now do not, but they insisted the issue is firmware related. So the next step is to remove the Easy Starts and ship the units back to Micro-Air for the firmware update.

I had seen one reference to a firmware update on the Victron Community forum, but just one random reference with no further details or discussion.

I'll continue to update this thread with more info as I proceed to solve this puzzle.

Crazy but it makes sense I guess. Shame you need to pull them and send them in.

[howson]

I ran down my battery bank to 10.5v and then let shore power charge up the bank going through the bulk, absorption and float mode for ~24 hours. Tried the air conditioner again and still won't run. Micro-air has not responded further with an explanation on why the system ran fine previously but now doesn't.

I'm going to pull the EasyStarts tomorrow and get them in to the mail for the firmware update. I'm going to have to try and run the air conditioner without the Easy Start, too, just to see if the inverter will do it. (I seem to remember it would...and should...so we'll see.)

[ncitro]

I ran down my battery bank to 10.5v and then let shore power charge up the bank going through the bulk, absorption and float mode for ~24 hours. Tried the air conditioner again and still won't run. Micro-air has not responded further with an explanation on why the system ran fine previously but now doesn't.

I'm going to pull the EasyStarts tomorrow and get them in to the mail for the firmware update. I'm going to have to try and run the air conditioner without the Easy Start, too, just to see if the inverter will do it. (I seem to remember it would...and should...so we'll see.)

I’ll be curious to hear. I think I’ve heard that they’ll run on the Multiplus 3000. Obviously it does not work as hard with the MicroAir.

Did they give you an idea how long the turn around would be? I’m surprised they wouldn’t send you new ones with the new firmware and have you send yours in. Yours aren’t that old right?

[howson]

I’ll be curious to hear. I think I’ve heard that they’ll run on the Multiplus 3000. Obviously it does not work as hard with the MicroAir.

Did they give you an idea how long the turn around would be? I’m surprised they wouldn’t send you new ones with the new firmware and have you send yours in. Yours aren’t that old right?

Turnaround is literally hours once they have them in hand. I bought the two I have in Jul '19. They've since changed the design.

At least they CAN flash the firmware! I'd be none-too-happy if they'd said "sorry charlie"...(remember that old tuna fish commercial???)

[ncitro]

Turnaround is literally hours once they have them in hand. I bought the two I have in Jul '19. They've since changed the design.

At least they CAN flash the firmware! I'd be none-too-happy if they'd said "sorry charlie"...(remember that old tuna fish commercial???)

That’s true I suppose. I’d be royally upset then.

[gbkims]

I'm going to pull the EasyStarts tomorrow and get them in to the mail for the firmware update. I'm going to have to try and run the air conditioner without the Easy Start, too, just to see if the inverter will do it. (I seem to remember it would...and should...so we'll see.)

Howard,

I've got an easystart I've had sitting on a shelf for awhile, it's got FRM A57 on the case & circuit board.
Perhaps that's the firmware version.
I'll be very interested to see how this plays out with your easystarts.

[steve&renee]

I'm going to have to try and run the air conditioner without the Easy Start, too, just to see if the inverter will do it. (I seem to remember it would...and should...so we'll see.)

I'm kind of perplexed about why you're trying to run the AC's with the batteries. Is this just a science experiment that you're doing in your driveway, or do you actually cool the camper when you're camping and not hooked up to shore power? I'm guessing each AC consumes around 15 amp hours. Sure, that's 26 hours -- but only if you start with a fully charged 400 AH bank and there are no other loads.

Please talk about your use case running the AC's with the batteries.

Thanks.

-Steve