AC300 to Transfer Switch

Has anyone connected the AC300 30Amp outlet to a transfer switch? I’d like to use it like a generator, and already have the transfer switch installed on my house.

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I haven’t done that for this unit but have for others. What concerns do you have?

I have installed a transfer switch at my home for my gas generator set in 1995 and I will use it with the AC300 and Fusion box . So what help do you need?

I was mainly curious to see if anyone else was using the device this way. I’ll need to make a cable since I can’t seem to find one to fit my configuration. The AC300 is 30 Amp and the transfer switch is 50 Amp. I have a cable with the 50 Amp connector on one end. Just need to wire up the other end.

I plan to mostly use it as a UPS for my computer setup until an extended power outage. It would have been nice to have this during the deep freeze in Texas last year. Thanks.

I have the reliance pro/Tran 2, 10 circuit transfer switch installed and used with my dual fuel generator for when grid outages.

I purchased 2 ac300 and 2 b300 (split phase bundle) in September and recently received everything except for the p030a fusion box that will be shipped in February. In the absence of the fusion split phase unit and could not connect to the transfer switch, I went on Amazon and purchased a TT30 to L14-30R adapter cable for $22. The cable enables both L1 and L2 to be live on the L14-30r side. I connected the cable using one of the ac300 to the house reliance transfer switch and switched over 5 circuits to the Gen side to use the Power from the ac300. Everything worked with no issues. 5 circuits covering my family room tv, router, stereo etc…, kitchen with frig and stove. Bedroom, garage and sump pump. I also tried the furnace line with the blower fan running. All is good. I ran it for about 15 mins and saw the power went from 100% to 97%. I switched everything back to grid power and charged up the ac300 back to 100% and powered off everything. Now just waiting for a real grid outage. I will probably power the systems up once in a while just to make sure everything still works.


My transfer switch uses a ABN L5-50R connector, so if I can’t find a cable I’ll need to make one.

We’ve had our AC200 connected to our transfer switch for about 8 months now…everyday. Fed by 6x210 watt solar panels. On in the AM off at sundown. Powers most of our house during the day. Shaves off 20-25% of our power bill and is a kick ass backup solution.


Hey guys I was hoping someone could help me diagnose a problem: I just got my AC300/B300 combo, and hooked it up to my Transfer Switch similarly to t4602yf (TT30 from RV-port to L14-30R port on Transfer Switch). I have the AC300 set to standard UPS mode. I am able to run circuits off the Transfer Switch with no problem, whether the AC300 is feeding from AC power or battery power. Automatic switch-over when utility power goes out works great. However, whenever utility power is restored to the AC300, I get an alert “012 BUS Voltage High”, and it shuts off my AC Output. Clearing the alert and turning the AC Output back on makes it work again.

This happens whether all the transfer switches are set to Line or Off or Gen. It happens with or without devices plugged directing into the AC300’s other AC sockets. Unplugging the transfer cable makes everything work fine with the UPS and devices plugged in there. I’ve tried two different cables to the transfer switch with the same result, whether from the RV-port or the AC sockets. Same problem.

The AC300 is plugged into a dedicated 20 AMP circuit.

(I don’t know if this is a clue, but some of the transfer circuits are connected to ARC-fault breakers in the main panel. When switching them over to “GEN” on the transfer switch, they frequently will break (half-way).)

Any idea how to diagnose? Thanks!

When I switch the power off, or to gen on the transfer switch on a line that has an arc fault breaker, the arc fault breaker always trips to off on the main panel. I read that that may be the way the arc fault breaker works. No power, or arc fault, it trips. Thus settling the power to off or gen cuts the power for that breaker on the panel and I think that’s why the tripping. I don’t think this has any impact on the alert on the ac300.

my ac300 has to be plugged into a gfci outlet Simply because that’s the closest and one available in the utility room. Otherwise I need to install a non gfci outlet which I will probably need to do. My situation is when the ac power is turned on the ac300 while plugged into the gfci, the gfci would trip. If the ac power is off, it is ok and can charge. I have not successfully tested ups mode due to the gfci tripping.

Thanks William. Yeah from what I’ve been reading, tripping ARC faults is par-the-course. Kind of limits the utility of UPS mode unfortunately.

When I initially plugged in my AC300 it would trip the GFCI outlet I had it plugged into. Lowering the AC input current to 10A from 15A fixed that problem for me if you haven’t tried it.

That’s interesting. I will try that just to make sure it does the same for me. I was able to plug the ac300 through an extension chord to the furnace non gfci outlet and it did seem ok charging and drawing power at the same time.

I’m running my AC300 to a 30 amp transfer switch and have it permanently running two circuits (basically keeping it in PV Priority UPS and always running off the AC300). Works great. I just had to buy an adapter for going the three prong to four.

Brian: if you unplug the AC300 from the wall and plug it back in (i.e. simulate utility power coming back on after an outage), does it keep sending power to the transfer switch? This was the only part of the scenario that doesn’t work for me. It causes an alert and shuts off AC output on the AC300.

Well I’m glad you mentioned this! I’m not sure what’s happening but you’re right… my unit now seems to not start AC power output after power interrupt. It’s doing the same as you described above. Hmmm…

Sounds like When power is lost and comes back, the ac300 initializes and thinks it is starting from scratch instead of a restart. It does not maintain the last operating status. Bluetti needs to maintain the operating state cross restarts. or provide a setting to start the dc or ac power after the unit starts. They may be hesitant to do so since they may not want to start the power unsupervised.

Agreed. Does support monitor these threads? I might call them tomorrow. This is clearly an error. If anything they should allow turning the output on via the app after restart.

Actually we can rule that out because only the transfer switch doesn’t work – if I plug a device directly into the AC300 (e.g. a lamp), it works as expected.

There is something unique about the transfer switch. The only thing I could think of is the transfer panel is bonding neutral and ground. I believe the AC300 has a floating neutral (?). I tried plugging in a bonding plug into one of the standard output sockets but no luck. However, I don’t know if bonding one of those also bonds the RV port… ?

It would be nice if support could chime in. I wonder if a firmware update might overcome this…

I just tried it on my ac300.
I want to revise my previous post.
I turned on both dc and ac power (power to transfer switch running my frig) and unplugged the power chord as suggested.
When on ups mode, and ac300 loses power from the plug, the unit actually stays on battery power and is not rebooted. The dc and ac power stays on and runs on the b300 battery uninterrupted.

After I restored power to the plug, the dc power stayed on and the ac power is turned off. I believe because when power was restored, I received different alarms and I believe the alarm is the cause of the ac power being off. Once I cleared the alarm(s) I can manually turn ac power back on.

I did this many times and one time power came back automatically after I was able to clear the alarm and when the alarm cleared, it automatically turn on the ac power inverter. All Other times I had to clear the alarm and power did not come back automatically and I had to turn it on manually with ac power on/off menu.

Different times I got different alarms.

Most often i received alarm 12 bus voltage high
I also saw alarm 11 H bus voltage high
Also saw 15? Grid voltage low? Not in manual

I did another test with an accessory plugged into one of the ac300 20a outlets and transfer switch into the 30a tt30 port. Power chord plugged in and turned on the dc and ac inverters. I unplugged the transfer switch and just left the 20a unit and then unplugged the power chord, the ac inverter stayed on. If I then plug in the transfer switch into the tt30 port, I get the alarm 12 and ac inverter turns off. Clear the alarm and turn ac inverter back on with the transfer switch still plugged in and ac inverter comes on and everything works. I agree must be something with the transfer switch causing the alarms. But one time I plugged in the transfer switch and the ac300 did not throw any alarm. This is very sporadic.

FYI I tried your experiments and am getting the exact same results on my AC300.