AC300 simultaneously throwing error 025 and 026

In the past two weeks, my AC300 has shut off A/C power with error codes 025 and 026 simultaneously. I can turn A/C back on after clearing the two codes. Does anyone know what causes these errors?

025 AC Relay Short Circuit
026 AC Relay Open Circuit

Hi @tpkidd3 ,
We suggest you turn down the current and try again to see if the error continues to be reported.

I am already running on the low current setting because its quieter that way.
Just curious: What condition would set these codes simultaneously?

What firmware version are you running?

Attached screenshots from AC300 and batteries.


For the DSP Version, check if you can gain access to 4031.11 from support. You’ll need to provide your serial number. This has some fixes that resolved an AC Relay error that would get previously.

Thanks for the recommendation. I will give that a try.

Do all DSP updates have to be done this way or is this some kind of special test/beta version?

This is an unreleased version that fixes specific issues. Normally the update will just appear in your app. This version fixes some issues with the AC input and when running in split-phase mode.

Does anyone know what conditions set codes 025 and 026? The description isn’t very helpful.

Hi @tpkidd3 , Because of the weak grid, AC300 will report 025 026 error if the charging current is too high. Thank you

Thank you.
Very informative.

I was charging off 15 amp power at the time.
Will keep an eye on incoming current.

I have a similar issue running
At random times it will get these

025 AC Relay Short Circuit
026 AC Relay Open Circuit

And then AC will turn off

I have to manually monitor when this happens - I have bought multiple power failure monitoring devices to know when this happens. The only way to fix it is to clear the two alerts and click on the AC ON and click on OK and power starts up again.

Today it happened at least two times - this is CRAZY UNRELIABLE. Is there a software fix for this or is the hardware bad?

And then our refrigerators and freezers are not keeping the food cold anymore.

I am totally sure I am not exceeding the 3000 watt - it only uses 1500watts for the refrigerator that is plugged in - and this results in ac being turned off - how can I get access to the patch that fixes this?

I have two AC300 units and both are running into this periodically which makes them completely unreliable to keep my food from spoiling.

both AC300 unit have
IoT current version v9014.10
ARM current version v4032.09
DSP current version 4041.09

I did not run into this on the first unit when it had an OLDER firmware which unfortunately I upgraded thinking that it was good to run on the latest firmware.

How do we get the fixes so that we can have two reliable units as we assumed it would be when we purchased them?

at this point I have spent $200 to get power failure monitoring equipment just to make sure my food does not spoil

I would charge your system fully and then disconnect the AC charging cable. Next run your fridge and freezer running on battery only and see if you still experience these issues. If it does not occur on batteries then you are not exceeding the capability of the AC300 system and you may be experiencing an issue with DSP 4031.09.

Also remember that when a fridge/freezer starts up initially it can pull around 800+watts to get started and then settle down to a running wattage, maybe of <200 watts each.

I’m personally running one fridge and 5 freezers on my system with no issues… so we’ll get you up and running. Let us know your results.

Are you running any monitoring or surge protectors on your setup? I have seen that a surge protector after the fusion will through these errors and also a weak power error… I don’t remember the error number.

Been 2 weeks without the error codes. The new normal state is to have the AC300 set to draw just 9 amps. This is low but sufficient to keep the two B300s topped off. Typically plugged into campsite or house power, occasionally an 1100 watt inverter generator with a 9.2 amp max current is used if no shore power is available. If a quick charge is needed at a campsite, temporary set to 20 amps works on an RV 30 amp outlet. But normal day to day is set to 9 amps.

I have always had a pretty good surge protector in front of it and even replaced it and it made no difference. Still had this happen 3 times in two hours.

I would still run the battery only test and see if your experiencing the known bug with grid charging and surge loads. If confirmed, I can try to get you access to the next firmware that will help this specific issue

Specifically what should I do to perform the test?

fully charge your system, then disconnect the AC incoming grid charging cords. Run your loads as normal and see if you experience any issue. If you do not, then you may be experiencing the surge load issue with AC charging enabled.