AC300 blows grid circuit when AC out is turned on with transfer switch sub panel live

I had an electrician install a reliance pro/Tran 2 R310A. I connected the L14-30 to the AC300 30A outlet. When I turn the AC out on, the circuit the AC300 AC charging cable is plugged into throws the breaker. The circuits connected to the pro/tran2 work off the batteries but the AC300 cannot charge from the grid at the PV priority UPS threshold because the circuit the AC300 is plugged into always trips.

I’ve set the max amps grid input to 5A but that doesn’t solve the problem. If I unplug the L14-30 connection, the AC300 charges without issue with AC output on but as soon as the L14-30 cable is connected, the circuit the AC300 is plugged into throws again.

Anyone solve this problem? I was hoping to keep the grid connected so that batteries never dropped below 40% while relying on panels above that.

The below thread is the same topic. Long story short the Reliance Pro/Tran and that series of switch do not isolate the neutral wire and isn’t a true transfer switch.

When you say the outlet where the ac300 is plugged in throws again. Is the outlet or breaker where the ac300 plugs into a gfci outlet/breaker? Or Afci arc fault breaker. I had plugged in the ac300 into a gfci outlet and it would trip. I then swapped out the outlet from the junction box to a regular outlet and it worked. But the outlet is gfci for a reason so not recommended and I switched it back to a gfci outlet this morning. In my case, that gfci had downstream exterior outlets. Try another breaker or line. I’ve used an extension chord to reach another outlet as well.

So, I found a circuit with a normal breaker. It was wired to the transfer switch. I set its switch to LINE while the others were on GEN. When I plugged the AC300 into it, the controller popped. Now when I turn it on, and turn on the AC out, I get an error 008. OCP(Over Current Protection)-Hardware.

The unit is completely unusable now.

Also, the APP is returning 404

According to the thread you linked to, users were able to connect the panel and charge their AC300 at the same time. The issue they had was when power went out and came back on, causing the AC output to turn off. That isn’t my problem. I can’t get the AC300 to power circuits and charge itself.

Of course now I have to get a replacement AC300 since this one apparently blew up.

Other threads talk about a Bluetti fix to the AC300 that is supposed to be for transfer switches but actually causes this problem.

I don’t think you read that thread thoroughly… The transfer switch your using Pro/Tran does not switch the neutral wire from the main grid. It only switches the hot wires… Bluetti support has confirmed that you need a switch that isolates the neutral wire from the main grid otherwise you will get a 008 hardware such as you just did.

I think there are 2 issues. I have the pro tran2 switch. My 2 Original ac300s with the ac power cord connected with the protran2 switch plugged in the the ac300 would charge and be connected with the protran2 running with the ac output on with no issues.

The issue is to Unplug the power and plug it back in to simulate a power outage with a power restore. My original 2 ac300 would stay running but shuts the ac output with a high voltage alarm. I Must clear the alarm and manually restart the ac output and everything would run.

Winnie requested I send a unit back to bluetti to troubleshoot why the ac output shuts off. Then Winnie sent me a new ac300 which I did not retest. I emailed her asking a status on their analysis and troubleshooting of the unit that I had sent back. She did not give me a status. Instead She came back asking whether the ac output shutting problem was still happening with the new unit that she sent replacing the one I sent back. Since I did not retest, I went and retested a few days ago. Doing so, I encountered the 008 OCP with the power chord and protran2 connected. The ac300 actually popped with a shorted loud sound when it happened and died and won’t power up.

Bluetti support told me that the 008 OCP happened because the neutral of the grid was not the same as the neutral in the ac300. They claim a new firmware fixes the issue. They said the new ac300 they are sending me fixed the issue. It is unclear to me whether new hardware or new firmware or both was needed to fix the issue. I was concerned about my other unit and asked whether I needed to send that one back and get a new one. They came back with no exchange is needed but make sure I am on the latest firmware.

I received an RMA from Winnie on Thursday and shipped my ac300 to Las Vegas via UPS Friday morning. I am waiting for Winnie to send me tracking and a new unit.

I am not sure how all these issues are related with the protran2 switch. you are working with support on a new firmware to be tested and provide more tolerance with shutting down the ac inverter/output?? Even though the protran2 does not isolate and switch the neutral, the firmware you are working with support might help with protran2. And granted the protran2 may not be ideal because of not also switching the neutral.

I had almost the same experience and my unit is now unusable. Have an email with video sent to BLUETTI with no reply yet. Have you achieved any resolution?

Bluetti sent me a replacement ac300 for the 008 OCP ac300 was returned. They sent a newer model supposedly has hardware and firmware fixes applied to cure the 008 issued. You need to email bluetti service. They are a little slow responding but they do respond. Make sure you email to the correct email address :

Email them and include your order number, the ac300 number and the serial number on the sticker on the bottom of the ac300. Take photos of the ac300 and bottom sticker and attach to email. Ask them to RMA and send you a return ups bluetti paid mailer label.

Thank you! This gives me a little hope that didn’t spend all this money for nothing.

@sk1954 they are understaffed apparently. Getting through on the phone is a full time job but once you do, they will help. My replacement AC300 arrives tomorrow.

It will have been 23 days by the time it arrives.

Ok, thanks, I’ll keep at it.

Oh, I forgot to ask. I also have the transfer box set up and it was when I plugged in the ac charging cord while the unit was pv charging and that is when the OCP alarm came on. Does this mean the ac300 will not, ever work with the transfer box and I’ll have to find another set up? Thanks.

@sk1954 sorry for the late reply. I first bought the Reliance ProTran2 transfer box and I was not able to charge from the grid while powering the circuits in the ProTran2 switch. This is because the neutral connection on each circuit is not switched using the ProTran2 sub panel. I had to buy, and you will as well, another sub panel that switches neutral when switching off the grid. I went with the Reliance XRC0603A. I just got my 2 arrays mounted and the cables buried and haven’t had the new sub panel installed yet. Also, it’s my understanding that I will have to install a grounding rod on the solar arrays when the new sub panel is installed to ground the system when neutral is switched off the grid.
I’m working around the issue with the ProTran2 by manually switching back to grid when the batteries get low and not charging at all from the grid. It’s almost 8:30 am here and I’m currently generating 1000 - 1200 watts with full sun.
I will update once the new sub panel is installed. I’m really looking forward to being able to rely on the grid for a minimum battery charge so I don’t have to switch back and forth.