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.

My AC300 has three B300 batteries connected. I too grid charge with three T500 chargers connected directly to each battery. Works great with ac loads connected while using my Pro Tran II transfer switch.

Update. On my third AC300 due to 0800 error and complete shutdown. Decided to NEVER AC charge from House and turn AC on output at the same time. Removed ground from neutral on output. Guess what? 0800 now twice whenever I AC charge after a couple hours. AC output OFF. Nothing connected output wise. Limited AC input to 2 amps. PV DC input around 500 watts Max 1200 watts.
Conclusion. AC300 sold in Europe has a basic issue still not resolved.

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Finally have a working AC300 system. There’s a lot of talk about firmware updates, so I don’t know if this is working due to a correct configuration or firmware changes or both, but I am now able to charge the AC300 from grid using the PV Priority UPS setting. The solution was to change the breaker on the circuit the AC charging cable is plugged into from AFCI/GFCI to a standard breaker. The electrician also rewired the neutral from that circuit to a bus bar (I’m not an electrician so I can’t give you the exact details on that). The circuit the AC charging is plugged into is NOT one of the 10 circuits routed to the ProTran2 subpanel. The end result is that I can now switch the batteries to run the 10 circuits on the ProTran2 and maintain a 30% charge on the batteries from the grid source without 008 errors eliminating the need to manually switch on and off grid.

This configuration was necessary because my XRK0605C subpanel is designed for 220v and I only have one AC300 currently. You can buy parts to use this sub panel in a 110 configuration but some day I hope to upgrade to 2 AC300 units with 220v so I’m leaving it as is until then since the Bluetti sub panel is permanently temporarily unavailable.

Issue appears to be resolved with firmware upgrade. DSP 4036.05
To date no more faults.

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The code is clear on how to bond a neutral so a bonding plug is not legal per the NEC. Your floating neutral bluetti would need to have its neutral bonded thru the transfer switch to the house neutral. That house neutral is bonded at the first means of disconnect…your main service panel.

Curiously, has anyone tried the Connecticut Elec EGS107501G2 transfer switch? From what I can tell, it works with a floating neutral (as in, AC300) while allowing individual circuit controls. Kind of best of both worlds.

Thoughts? Anyone go this route?

After reading this through can anyone please help to confirm if I have correctly understood what you are saying about complying to neutral bonding and connecting into your home circuits.
You need an EZ or equivalent Either Or switch to completely seperate the current on both wires between the grid and the home Bluetti power source. This allows the unbonded earth connection between the Bluetti power source and the home circuit s grounding rod in the ground but with NO conflict to the balence in the currents coming from the grid nor creating a secondary bonded ground loop. Hence converting your home electrical system or critical load into a floating ground circuit. So as this is not very intelligent nor in conformity you use an earth bonding plug in one AC outlet of the Bluetti changing the current from 50 / 50 per wire into one 100% live wire and one 0% neutral wire bonded to the earth. Then the Ground Fault Circuit Breakers in the home system will work again, saving lives, with no conflict for the Bluetti nor the grid current. This way we are not using the grid neutral bonded ground.

I’m still so confused lol. Crazy how little they offer in terms of support. The language barrier gets in the way sometimes. I think they know what they are trying to say, they’re just struggling to relay the words to us.

What is the status of using Pro/Tran Model#3006hdk with a AC300 (purchased in August 2023)?
I am currently not usually charging with grid AC…only PV. I don’t plan to use AC to charge if I can help it. So far, for where I placed this AC300 (and one battery) into service, in my barn, solar has generated all of the power I have needed the past month, running an AirCond a few ours a day, and other shop stuff. But, that was September…lots of fair weather. So, come winter it could be necessary. Although with only 2 of 6 460w panels connected so far, I am fairly pleased so far.
The plan is to use a gas generator to charge the AC300 if necessary in the vent of a power outage. and no sun.
I ordered the Reliance Pro/Transfer and THEN found this and a few other WARNING threads from Aug 2022.
My plan was to run barn circuits that I might need on AC grid power if necessary, but keep on the AC300 most of the time on PV charging only.
The main circuit is the 120v Air Conditioner as well as some plant heaters. I need to be able to switch them from AC300 to grid power as needed with out running extension cords. For right now, I pulled the wire form the circuit to the window unit…put a plug on it…and plugged it to the AC300. But now, if I want to run it on grid power, I have a plug in the way.
So, I don’t really plan to charge the AC300 with grid power, but do want to switch over some critical circuits back to grid power. Is this doable? Is it possible to modify the Pro/Trans that I have?
Also, the barn electrical panel is a mess…so I could do what ever I need to do to it. And, re4ally, I want to possibly backfeed to the house in the event of an extended power outage to power fridge/freezer, a few lights.
The barn, where the AC300 is located, is a sub panel on a 60amp breaker on the main house panel, and I have a main line disconnect to disconnect all service from the utility line, and a generator connection closer to the house main. But, I want to be able to keep the AC300 in the barn, and send power to a few circuits at the house. Or does this neutral ground issue mess all that up?

@DrewLoker i have been using the ProTran II successfully, first with the AC300 and now with the AC500. It works but probably wouldn’t pass inspection. Best bet is to go with the provided panel from Bluetti, made by the same people as the ProTran II.

Ouch…that is kind of expensive. Especially since the plan is to not use the grid power, to charge or switch over some circuits to grid power if the battery is running low. I would rather put that $619 toward another battery…which I am planning on buying soon anyway.

But back to the Pro/Tram 2…which I got as a refurb for only $218 (looks like new…probably somebody like me realized they could s\easily use it, and packed it right back up and sent it back). I can return it, but I would rather not.

I don’t need to worry about any inspections (country home), but I do want to make sure it is safe…and the risk to the AC300 is low. So, is it possible to use the AC300 with modification?


@DrewLoker the transfer switch doesn’t charge by grid at all, it just switches the 10 connected circuits from your distribution box to run from the AC300 power output. The issue with my ProTrans II, and yours, is that the neutral is NOT isolated, which it should be. The switching panel Bluetti provides DOES isolate the neutral so that there is no neutral connection back to the distribution box when you switch the circuits. The potential danger is that the system could possibly feed power to the grid when the grid is down creating a threat of electrocution to linemen working the outage. It is an unlikely outcome but possible if power travels the neutral line, which it can do according to the expert electricians commenting here.

You can always manually throw the main breaker when the grid is down but that assumes you are always present to do so. This is why they have codes requiring a neutral isolating switch.

I have purchased the Bluetti switching sub panel, but haven’t been able to get an electrician to change over yet.

Regarding the back-feeding of power to the grid via a transfer switch, that would defeat the whole reason of using one, and it will not happen (barring a wiring error of some kind). It is OK to have the neutral common across independent power sources as there is still no way for power to get from one power source’s wiring to the other’s (there’s no closed circuit loop between them).

@hnymann code requires neutral switching in the transfer switch for anyone connected to the grid. It does work with a common neutral but it is illegal due to safety concerns for risk of fire and harm to line workers.
I’m not an electrician but someone decided backfeeding is enough of a risk with a common neutral transfer switch, to set codes that eliminate the possibility on grid connected residences.