I have an AC300 that has worked fine for me for just over a year. I have used it virtually 24/7 for powering parts of my home office on solar power mostly, occasionally using the grid for backup when power goes out or solar was not enough.
Recently, I purchased another AC300 and the required cables to run in split phase and power some more of my office. The two AC300’s were able to synchronize and I tested the L1 and L2 as 240volts at the end of the TT30 + TT30 cable that outputs to L14-30. I plugged the L14-30 into my generator inlet port, turned on AC power at the master AC300, turned off the grid into my panel and then turned on the breaker from the generator inlet box. Nothing. No power. I removed the AC300 cable and replaced it with a gas generator with another L14-30 cable connected to the generator inlet port and all worked. Strange!
I tested each AC300 individually for grounding issues and found the original AC300 I have used for just over a year to have some strange issues that the new AC300 did not have. First, when I plugged an outlet tester into an outlet on the old AC300, the 3rd light would lightly blink (2nd and 3rd light on = Correctly wired, only 2nd = Floating neutral). The new AC300 only had a solid 2nd light on. Then I tested the outlets on the old AC300 with a multimeter. Hot to neutral was 118.8 volts (good). Hot to AC300 ground was 28.5 volts (??). Neutral to metal box/ground was 0.8-0.6 volts (borderline). These readings were all done while the systems was under load, powering my PC, TV and internet equipment at about 300-400w.
Not sure what is going on with the old AC300, but it still works fine for powering my 120v equipment, even with the strange test results. I would love to get the system working and powering my garage panel via the generator inlet using split phase functionality. Any ideas what the issue could be? Any other tests I should be running?
Thanks in advance for any help.
Rick
Please see my answers to your questions below:
- Key question to confirm:
Is your TT-30 to L14-30 output cable the official BLUETTI split-phase cable? answer: Yes. Has the Bluetti logo on it and AC1 and AC2 labels as well.
- Split-Phase Setup Check:
Step 1: Connect the communication cable between units. answer: this was done when I tried to connect to generator inlet
Step 2: On the screen: Enable split-phase mode, then assign Host and Slave roles. answer: this was done when I tried to connect to generator inlet
Step 3: Connect the unit’s output to the split-phase cable, then plug the cable into the L14-30 generator inlet. answer: this was done when I tried to connect to generator inlet. Then I enabled the master AC300 AC out, then I made sure grid breaker was off, then I turned on the generator inlet breaker. No power was evident to any of the breakers on the panel.
- Testing Conditions:
When grid-connected, the unit auto-grounds. Did you test both old/new units under identical conditions? answer: Would it matter if the AC300 had a load on the AC output when I tested the hot wire to ground voltage? Do I need to test the new AC300 hot wire to ground with a load on it? That is the only test I performed that was not in identical conditions. I am curious what you think of the old AC300 having voltage on hot to ground test where the new one does not.
If the new unit was not grid-connected, a floating neutral is normal (no ground reference exists). answer: understood
@rickwagner50
Thank you for your verification.
- Is the output of the L14-30 plug normal?
- If the split-phase output line is functioning properly, then the issue might be with the distribution panel. Has your transfer switch been turned to the GEN side?
I tried the split phase connected to the panel generator inlet port again and same result, nothing powered up.
The output of the L14-30 in split phase mode seems normal to me. L1-L2 = 240v. L1-neutral and L2-neutral are both 120v. L1-ground and L2-ground are 0v.
I do not have any grid connections to either of the AC300’s during this testing nor when I connect the L14-30 output to the generator inlet port. I also disconnected all plugs that were powered from the AC300 120v plugs. Would not having grid/AC in connected to either of the AC300 units make a difference? I am powering the main panel with the generator inlet, not a transfer switch, so I am afraid of creating a loop if I plug the grid into the AC300 and am powering the main panel by the AC300 in split phase mode. FYI - I use an interloc switch to ensure grid is off before generator inlet breaker is turned on to power the distribution panel with the AC300 in split phase.
Thank you for your assistance on this, much appreciated!
Rick
The technical engineer suggests: Could you have an electrician check the specific situation? According to the tech analysis, the AC300 output appears to be functioning normally.