LV2424 x2 Split Phase Operation - Blowing Breaker

[EddieB]

Hello,

I have been running a single LV2424 for about 3 months and this week added a second unit. I would like to run them in parallel to power to an AC distribution panel in a single phase. They are both set to PAL, with one as slave and one master. Each is connected to 2.2 kilowatts of solar panels.

I have wired 2 20 amp 120 volt AC circuits for these two units as grid backup for when solar and battery are insufficient.

Everything appears okay except the first unit is now unable to draw from my AC as a backup as it previously had. Whenever i connect the AC input to the first unit it blows the 20 amp breaker immediately. This unit had previously been running solar with AC backup with no problems. The new unit, unit 2 can be plugged into either AC circuit and will draw power normally as needed.

Any idea what is going on here?

 

[EddieB]

Upon further inspection I have found that the P1 unit is actually read 100 volts on the AC input even though the unit is set to GFD for feed to grid disabled...

 

[Hedges]

"I would like to run them in parallel to power to an AC distribution panel in a single phase."

Are their outputs presently connected together? If so, Isolate them and try again. Check voltage between the outputs you want to connect. Make sure there is zero volts not 240V between them.

Another test, isolate the new unit and see if original one still works as before.

Don't know about yours; my monitor the input and make sure they are correct voltage and in phase before connecting.

 

[EddieB]

"I would like to run them in parallel to power to an AC distribution panel in a single phase."

Are their outputs presently connected together? If so, Isolate them and try again. Check voltage between the outputs you want to connect. Make sure there is zero volts not 240V between them.

Another test, isolate the new unit and see if original one still works as before.

Don't know about yours; my monitor the input and make sure they are correct voltage and in phase before connecting.

Both hots are connected together and hot to neutral it reads 120 volts.

Interestingly I found I can plug them both into the same outlet and it does not pop the breaker immediately, but having them both on the same circuit doesn't deliver the 40 amps I intended.

 

[Hedges]

Sounds like the other outlet is a different phase, different half of the main breaker panel.

"Both hots are connected together"
Did you try isolating them, then connect AC in to both units? I'm expecting that their two output hots will then be 240V apart.
Or maybe 120V apart? Could one of your AC outlets be wire backwards to neutral is hot and hot is neutral? (Or your cords to the inverters?)

Better isolate neutrals on output of inverters too, during the test.

 

[EddieB]

Sounds like the other outlet is a different phase, different half of the main breaker panel.

"Both hots are connected together"
Did you try isolating them, then connect AC in to both units? I'm expecting that their two output hots will then be 240V apart.
Or maybe 120V apart? Could one of your AC outlets be wire backwards to neutral is hot and hot is neutral? (Or your cords to the inverters?)

Better isolate neutrals on output of inverters too, during the test.

Thank you for your help.

My neutral and hot were flipped on one of the circuits.