AC300 split phase and P030A

The P030A finally arrived and I spent some time testing it. I have run into two issues and am curious if others have.

First, the 30amp outlets on the AC300s which the P030A plugs into are inadequate. The plugins nearly immediately hang out, pull out a little. they stay in, and are usable, but they don’t remotely stay plugged in snugly. I believe this is a quality issue with the outlet. Though I haven’t actually gone and grabbed a 30amp cord from my RV to see if the same problem happens.

Second, the management logic for the split phase load doesn’t distribute the load properly. I’ve swapped master and slave responsibilities just to be sure. Regardless of that setting If I draw 4,000-4,500 watts or so, It puts most of the load on one AC 300, eventually overloading it. One time the split phase configuration put an 800 watt draw from one AC300 and 3,300 on the other. Another time the split phase functionality it put a 200 watt draw on one AC300 and 3,800 on the other. Each time I tested this (4 or more times in the end) I started with ZERO load, added a few hundred watts here and there. Then added a space heater (which pulls 1,500 watts) and a single water pot heater (pulls over 500 watts) and it would never distribute the load properly.

Because of the 2nd issue above it is not possible to reliably pull more than 3,000 watts at a time using the P030A and split phase configuration without overloading the systems.

When I received my P030a, I did some minor testing. I had already purchased 2 tt30 dog bone extensions from Amazon because I did not want to keep plugging in and out on the ac300 30a outlet which could wear it out. I alternated use of my 2 Ac300s and my transfer switch. So the dog bone is always mounted on the 2 Ac300s. When I got the P030a, the cables each plug into the dog bone. I found the dog bone maintained a pretty solid connection between the ac300 and the cable from the P030a. There was very little play as the dog bone plug/interface was flatter and plugged in flat onto the ac300 30a outlet. About $32 for 2, i thought it was a good investment. Photo enclosed.

In regards to the split phase, I used a volt meter and measured the voltage while using the p030a. The 30a and 15a outlets on the p030a outlets measured close the 120v. The L1 to common and L2 to common on the L14-30r outlet each measured close to 120v. However, measuring L1 to L2, I did not get 240v. The voltage kept fluctuating on me. Needless to say, I did not actually use it on my transfer switch. Only my central air on my transfer switch uses 240v. I did not test any further.

If the P030A Fusion box pro does not output the sum of the two 120 VAC lines as 240 VAC, then they are not exactly spliting the phase or 180 degrees apart. There is a trigonometry formula to calculate the sum of the two wave amplitudes from zero to 180 degrees of phase difference. The electronics inside the Master AC300 must keep the outputs correctly as any phase change will reduce that output down to 120 VAC when the phase difference is zero, or at the same phase angle.

I bought the same system but I have not installed it yet. I will also post results here. I do expect the Bluetti/MaxOak engineers to be reading these posts.

Thanks @t4602yf I’ll see about getting the dog bones. I don’t necessarily care about 240, but I need to be able to allow my house to pull 4,000-6,000 watts at least for short periods of time when needed and not have the system shutdown. Not being able to do that defeats the purpose of spending $12,000+ for this configuration.

@Raymondjram I look forward to seeing if you have the same results as I have.

I attempted without success to utilize the NEMA L14-30 plug and socket configuration for the 30 amp outputs since it is a more secure, locking connection and is fairly std. for generator connections. I believe the RV plug was utilized due to the RV crowd being more familiar with that connection type. I would recommend the RV dogbone that terminates on the other end with the L14-30 connection and use L14-30 beyond that point.



Hello everyone!

I am kind of thrilled to be taking delivery of 2 - AC300 and 4 - B300s today.

I went to use the hardware for split-phase 240V operation and powering of our entire service, if not for full off the grid operation, at least during outages, and want to have the 6 kW capability available. We have an 8 kW 240V gasoline generator in reserve that’s quite adequate for this, but of course with the noise and refueling disadvantages.

I ordered the AC300s/B300s from Amazon, as there were some promotions going on. I separately ordered a P030A / AC300 Fusion Box directly from Bluetti on March 6. I received order confirmation, but haven’t been notified of the shipping status of this unit yet.

Now, getting to the point. I am dismayed by what’s being reported in this thread, which was posted three days after I placed orders for the Bluetti equipment. If it turns out not to work properly in split phase, it is a deal breaker for me.

Matt2022, I presume that your split phase data cable is connected and seems to be in working order?

The catch seems to be that it is impossible to test split phase operation without having the P030A package, since this requires the proprietary data cable that comes with the P030A? So, creating a “fusion box” from the requisite connectors, etc., by itself, won’t help.

Accordingly, I am not going to unbox the shipment until I receive the P030A from Bluetti and can test split phase operation. I don’t want to be stuck with something that doesn’t work as (putatively) marketed… there is supposed to be a 30-day return policy, and if it comes to it I will very reluctantly bite the bullet and pay hundreds in return shipping costs rather than be stuck with an $11,000+ setup that doesn’t work as I expected.

I wonder how many customers have received and successfully tested AC300/P030A setups for driving a split phase 240V load?

Please, will someone from Bluetti give some reassurance that I am concerned for nothing? Is the design and hardware for split phase nailed down and usable now? Thank you for your understanding.


Robert, today I hace successfully activated the P030A Fusion Box Pro with my two AC300 and B300 setup. BTW, I ordered on Sept 23rd, and it arrived in January!. Since Bluetti does not ship to Puerto Rico, I needed a transport service for that order to reach me. And it did last week.

Here is a picture of the Fusion Box Pro on top of one of the AC300 units.

The meter shows 240 VAC at the two TT-30 outlets because the L14-30 is connected to my home through a transfer switch. I powered my home for over ten minutes during the test. So if you follow the instructions it will work.

1 Like

I did not meter the 2 live sides together of the 2 tt30. I metered the live and common of each of the tt30s and got close to 120v each.

I also did meter the L1 and L2 of the L14-30r on the p030a and got fluctuating voltages. When you get a chance, would you unplug your transfer switch and meter test the L1 with L2 together on the p030a L14-30r outlet? I don’t know why mine reading was erratic. Never got close to 240v.

I did measure at the L14-30R outlet and measured the same 240 VAC.

Today I added two 100 W solar panels to test the DC input and I gained several watt-hours of energy worth a few cents. But tonight I will test the UPS (Uninterruptable Power Supply) operation on my whole house, when I transfer the entire electrical home load from the utility to the AC300 setup. I will check the system tomorrow morning. If all goes well, I will continue the UPS operation for a longer time.

Eventually I will add an initial 1.6 kW (four of 400 W) of panels then grow to the full 6.4 kW (16 of 400 W) that will cover my home completely by solar power.

1 Like

Thank you. I must have done something incorrectly.

Raymondjram, thank you so much for your reply! :slight_smile: That is reassuring. I reckon that you tested the AC voltage while both legs had at least a few hundred watts of load on each?

I am still waiting for my P030A to be shipped.

What model of PV panel are you using, if you don’t mind saying? I am planning to have something similar once I receive the P030A and the rest of the system connected.



I have no panels yet. I am using my setup as a UPS because we get many blackouts. Our utility (PREPA) suffered damages in 2017 from Hurricane Maria, so it is weaken. Thus the need to keep power on with the setup.

Raymondjram, thanks for the reply (sorry to take so long to respond). Robert

As for the “AC Charging Cable for Split Phase” which is item 14 on page 6 of the AC300 user manual, I ask Bluetti if they have finally decided to produce and sell this special cable. I have been searching for the special Weipu Aviation Connector SP29 (as labeled on the connector) for the 120 VAC 30A inputs to the two AC300 units. The other end is a L14-30P male that any hardware store sells, plus the needed feet of cable. I know how it should be wired for the Split Phase application.

I have checked Weipu directly and other suppliers for that connector (SP2910/S3) which is a female plug with three solder pins. Most sites, including Amazon, only sell the male plug. Has anyone else found a source for the connector?

Has anyone actually successfully pulled 4,000-6,000 watts via the P030A with the load being properly distributed between the 2 AC300s? Instead of most of the load on one or the other and causing a shutdown?