Hi ,my VMII 3.5Kw plus inverter fail to start from grid (AC input) after a short moment of overload and the display indicates fault code 58 ?!?!

From PV and Battery is working normaly !

When i connect the mains (AC input) to the inverter,the differential circuit breaker goes down and the inverter fail to start !

Thanks.

1 hour ago, Attila said:

Hi ,my VMII 3.5Kw plus inverter fail to start from grid (AC input) after a short moment of overload and the display indicates fault code 58 ?!?!

From PV and Battery is working normaly !

When i connect the mains (AC input) to the inverter,the differential circuit breaker goes down and the inverter fail to start !

Thanks.

With differential circuit breaker do you mean an earth leakage (RCD)? 

Is the inverter AC input wired to get power after this unit? 

1 hour ago, Attila said:

display indicates fault code 58 ?!?

That normally flags abnormal output voltage either to low<190v or voltage to high>260v

3 hours ago, Attila said:

Hi ,my VMII 3.5Kw plus inverter fail to start from grid (AC input) after a short moment of overload and the display indicates fault code 58 ?!?!

From PV and Battery is working normaly !

When i connect the mains (AC input) to the inverter,the differential circuit breaker goes down and the inverter fail to start !

Thanks.

This is a nasty one and its got me head scratching. I can relate to F58 error , but that's typically when the DC-AC bridge has one IGBT not firing . In that case only half of the full bridge is working and the RMS output of the AC is half of rated voltage. But in your case the inverter starts correctly when DC is supplied without grid. And then when grid is applied , the overload occurs . I can only think of one failure mode which would explain such behavior, and that is if the grid / safety relay contact  is somehow shorted  or its coil control circuit is stuck in energized state . When working correctly  this relay eventually closes and connects the grid to the inverter output , but only after the inverter has synchronized to the grid. This failure could explain the overload as the grid is prematurely tied to the internal inverter output before proper synchronization has taken place. It also explain why the inverter is working fine from dc sources when grid is not attached.

This is a long shot , I could be wrong, and I would like to prompt @Coulomb to maybe shed light on this issue.

One way of checking my theory is to  physically remove the grid from the mains input terminals and then switch on  the inverter via battery only. Then check on the LCD display whether both the Mains INPUT and Inverter OUTPUT shows the same voltage.

In any case please refrain for the time being from connecting grid to the system. It could eventually result in the main board  being damaged.

 

EDIT : My theory could be wrong as I have just realized that the inverter should check for live voltage on its output before attempting to generate its own supply .  But I am not sure if the software is doing this test .

 

Edited May 15, 20242 yr by BritishRacingGreen

11 hours ago, Scorp007 said:

With differential circuit breaker do you mean an earth leakage (RCD)? 

Is the inverter AC input wired to get power after this unit? 

Yes the inverter is connect after differential circuit breaker!

2 minutes ago, Attila said:

Yes the inverter is connect after differential circuit breaker!

So what could be happening is that you have enough normal earth leakage due to switching power supplies to be just under the Residual Current Detector's limit. Then when you connect AC-in, there is a fair bit more leakage to earth, and the RCD trips.

It's highly recommended to connect the inverter's AC-in port before the RCD, and to have your usual RCD(s) at the output of the inverter to protect against shocks and worse.

Is the status of this thread solved or unsolved? 

If solved, kindly share with us so we can equip ourselves to help other members with similiar problems.