Help with solarmax grid tie on micro grid


New Member
Jul 16, 2021
Hi all
I have a unique custom diy system. I have a diy inverter based around eg8010 micro running off 48v 240v,8kw. I have a 5kw grid feed inverter connected on 240v side to 6kw of panels. I also have a igbt switch between panels and grid feed inverter to turn off solar input when battery is full. This has all been working in this micro grid tie setup for years.

Recently, the grid tie inverter has started on some mornings to fault with 'ac sensor error'. A reboot seems to fix it. I got sick of doing this every morning and after some research found this to be a common fault with this old grid feed inverter. So I purchased a brand new solar max 4000p inverter.

Now the fun began. After installation, it seems to get stuck waiting with 'restart Delay' on screen. I can wait all day and it never goes away. I can go into menu and confirm 390v DC coming in. If I flip breaker it says ac loss so everything seems fine there. I looked at waveform of 240ac
.looks good,... So I concluded it must be a faulty new inverter. I contacted seller, they sent a new one.

Guess what... Same thing!!!

So my question to all you smart people is what is going on here? What does this grid tie not see that is stopping it from working? I have good 50hz 240v ac, good DC..

Any pointers would be great as I have 2 new inverters that don't work. I have reinstalled old one now and just have to reboot it every morning..


Solar Addict
Jun 22, 2020
Not too familiar with this MPPT but...

Have you removed both DC bridges??