I want to lay out what equipment that I have along with information that I have gotten from Bluetti engineering people.
I talked with a Bluetti after sales engineer about solar panels and at the time I was looking at the Qcell Q-Peak BLK ML-G10+ 400W panel. These have no microinverters. He agreed that it met all of the specifications and should have no problem working with the EP500 Pro. They are 400W, VOC-45.3, IMPP -10.77A, SC-11.4A and I have 3 of these in series for 1200W. I have two sets of these for 2400 W total. These work very well and on one set I have gotten up to 1218W. I usually get at peak time over 2000W maximum on a clear day and varies between 1500W to 2200W depending on if it is totally clear. On a rainy day at peak time I will get around 300 to 500 W.
The panels are mounted on unistrut framing that has 4 sets of legs with two bolts each. I dug 10" x 18" holes and used 3" wide x 10" round cement forms at the top for a round flat surface of cement. Then on the 2" pavers I put 6" cement below the area where the legs were going to set and bolted into that area going a few inches into the cement. I used shielded cement bolts for the other 6 legs. This is rock solid but does sit a little lower than I would like but it goes above the local requirements for wind and all other criteria. This is in a mobile home park and things had to be down low according to park and local regulations. Thankfully we hardly ever get snow. If we do I will be shoveling.
In the house behind the Bluetti I have 2-250V 16A DC breakers that I talked to this same Bluetti engineer about. I wanted to match up what the EP500 Pro was using. What I found was that with the AC and PV cable connected to the EP500 Pro I could not power down the unit, but would have to unplug these cables to reboot. At night this would not be a problem but during the day I wanted breakers to kill the DC power and unplug the PV cable. This would also give me access to breakers if there was a solar panel problem. I will turn these breakers off during thunder storms that thankfully we do not get very often. Even though everything is bonded and grounded properly on the solar panels and frame.
When it came to a Transfer Switch I worked with the same after sales engineer above along with people at Reliance. For my situation with no GFCI or AFCI breakers but just GFCI plugs the Reliance 310A Transfer Switch would work. I needed 7 circuits so this gave me 3 extra circuits if ever needed. They did not have an 8 circuit Transfer Switch available at the time. It was either 6 or 10. This Transfer Switch has worked good with no problems. In my case the Switch is next to the AC panel and above the EP500 Pro.
On the Transfer Switch I had to tie the X & Y legs together from the switch to the X leg on the Female L14-30 plug on the Transfer panel. I was doing this since it was just 1 EP500 Pro with 120V output. I used a 10 gauge wire that was wire nutted to the two legs and then screwed it into the X leg of the plug. I wanted this setup to where there would be no back feed from the Y leg. I put this to Reliance and they said that would be no problem with the way this was setup. And the Bluetti engineer agreed that this should work. After about a month of testing I have had no problems at all. I have had no Alarms or Error Codes on the EP500 Pro.
I bought a heavy duty 4 prong generator cable rated for 30A for this unit. This has done its job. I would like to see Bluetti make it possible to use the twist lock on the EP500 Pro housing. I am assuming that the EP500 Pro has a standard female L14-30 plug on the inside. I have the plug inserted all the way in with the cable situated to support the plug. With this setup I have no issues with the plug coming loose.
I have a AC vent that blows on the EP500 Pro and that helps to keep it cool. I have run this up to almost 3K watts for some time with no heating issues. I did not think the fans were loud at this wattage load. This unit stays very cool and in normal running mode I barely hear the fans when they are on.
In talking with the Bluetti Product Manager he told me that when plugging into the front AC plugs it is setup as a Floating Neutral generator. Then when you are using the L14-30 plug in a Transfer Switch it is just like a bonded Neutral generator. He also mentioned that he was working with Reliance and in about September or so Reliance was to have a Transfer Switch that would be designed for a single EP500 Pro. He did not explain all of the differences with this new Transfer Switch but I am assuming that the two legs from the switch would be already tied into the L14-30 on the front of the Transfer Switch for one thing. The reason I say this is because our discussion was mainly around the Transfer Switch, Neutral, and the problem of a single AC leg 120V coming into a 2 AC leg 240V Transfer Switch.