WARNING! Do not use any NON GFI transfer switch with your Bluetti product

What is that @stick30 ?

Victron makes those transformers for a reason.
This solved my issue. I chose a 3000VA unit since I only charge using AC from my SMA inverter. Cost $180. I charge At around 250 watts but wanted extra capacity if needed. I pick between 1 and 2 amps depending on sun and this gets the unit charged back to at least 80%. No hum. I did add a separate charging circuit from the house and used a Type K instead of normal Type B circuit breaker. Type K in Europe is for transformer use and minimizes nuisance trips on turn on.

I get to keep my bonded earth and neutral and the 0800 error codes stopped.

I am in the US and have a ProTran2 310c installed and an AC200Max plus an AC500 on the way. I intend to power some circuits with my Bluetti to grid assist and for when the grid is down. Am I going to have issues? I told my electrician what I planned to do and he recommended this switch. I haven’t plugged it in yet but planned to this weekend. I have seen YouTube videos of this working with a Bluetti AC200Max.

My AC300 made a loud pop and gave me a 008 code and never would reset. This happened while grid charging and having loads plugged into the front of the AC300 without my Pro Tran II connected. Returned my unit back in early February and they sent a replacement. I have been using my AC300 connected to my 6 circuit Pro Tran II 24/7 for 7 months with not one issues. However I will not grid charge and use ac output at the same time in fear of blowing my unit. I ordered my unit back in 2021 when they first started production. Maybe hardware and firmware updates fixed the problem.

I too will not directly charge my unit with the grid… unfortunately if you get a high load on your system while it’s plugged in it appears to kill your system. I’ve been using the T500 on a schedule defined by smart plugs to charge my batteries directly… so far this has been working well.

Been awhile since I posted but I wanted to update.
I haven’t gotten around to having my new neutral switching sub panel installed so I’ve continued to use the ProTran2 workaround.
The ProTran2 sub panel can be used successfully but with the following conditions.

Connect sub panel circuits to battery

  • IMPORTANT! make sure AC charging input is NOT connected
  • connect the RV cable from the AC300 30Amp out to the ProTran2 inlet
  • Turn AC Output ON
  • press ProTran2 switches up
  • GFCI/AFCI switches on your main panel will trip
  • NEVER connect AC charging while the AC300 is connected by the RV cable to the ProTran2 sub panel and the sub panel is switched off grid

Reconnect sub panel circuits to grid

  • turn AC Output OFF
  • re engage tripped GFCI/AFCI breakers
  • pull ProTran2 switches down

Bluetti recommends a full discharge/recharge of your batteries every 3 to 6 months.

AC charging the AC 300 with ProTran2 sub panel

  • discharge batteries completely
  • reconnect sub panel circuits to grid (SEE ABOVE)
  • disconnect RV cable from AC300 30Amp Output
  • connect AC charging input to outlet
  • make sure Standard UPS is set in settings
  • Once batteries reach 100%, disconnect AC charging input
  • connect RV cable to AC300 30Amp output
  • connect sub panel circuits to battery (SEE ABOVE)

While this works, it probably isn’t legal because the shared neutral creates a safety hazard to linemen working to restore power during outages if your batteries remain connected. When switching off grid, use a neutral isolating switch. This also solves the issue of charging from grid while powering the isolated switch, making it possible to use the PV Priority UPS setting.

SIDE NOTE: I thought it would be smart to set my ground mounted panels higher than my 32 degree latitude angle to compensate for winter sun, but I’m finding that the cooler temperatures more than compensate for any shortened days or angle optimization loss. Now I have to rework the panels to a better summer angle.