AC output under voltage

[SteveK]

So my inverter worked well until I forgot and plugged in electric heaters into outlets which are fed by the inverter if shore power goes out. And the power went out for several hours.
Now it still charges and passes power through. But when it switches (can hear the click) if faults to AC output under voltage. I found one explanation that said the output voltage is less than 100V so it will not continue.
How do you fix this? Anyone have this happen, what was the repair?

It has an output breaker which is not tripped or at least will not allow being reset.

 

[kchace]

If the inverter is sensing that it’s own AC output is low, you may have an internal inverter problem. The only other thing I can think of is if the DC feed to the inverter is low, it could cause the inverter output to be low (though not likely) but normally if the DC feed to the inverter is low it should alarm and indicate that.

Ken

 

[SteveK]

Thanks it is doing the three stage charge and battery is 12.8 when I switch over.

 

[kchace]

Right. If it says AC it’s the output. You may have lost one or more of the output stages.

Ken

 

[EngNate]

You need to use a multimeter to verify that there is 11.8V minimum at the inverter's DC terminals when inverting/attempting invert. If No, correct that issue. If Yes there is an internal defect, most likely failure of power transistors requiring a board replacement. The circuit breaker and wiring will not cause the fault display noted.

 

[SteveK]

3 stage charging Bulk, absorption and float are working

The fault code solution says "Remove excessive load". But nothing is plugged in when I switch to invert. Guess I will take it apart, first thought is blown breaker that will not reset so I will bypass to find out

 

[oscar]

Start with a total de-power. THEN get the multi meter out.

 

[SteveK]

Start with a total de-power. THEN get the multi meter out.

By depower, do you mean remove battery cable as well as AC in.

Disconnected DC+ and turned off AC IN for 10 minutes, no change, same fault. Tomorrow, going to have a look inside.

 

[SteveK]

You need to use a multimeter to verify that there is 11.8V minimum at the inverter's DC terminals when inverting/attempting invert. If No, correct that issue. If Yes there is an internal defect, most likely failure of power transistors requiring a board replacement. The circuit breaker and wiring will not cause the fault display noted.

Thanks, checked and it is 12.8, internal defect, pulling it out and getting it serviced.

 

[catalinajack]

Don't know if this helps but yesterday my Magnum 2812 went into AC overload and shut itself down. My fault, of course. I have an outlet in the engine room that is dedicated to powering a Grundfos one-horsepower fresh water pump. I was doing some wiring and used that outlet for my heat gun. Pump came on, all power promptly lost. The fix was to turn off the double-breaker at the panel to reset the inverter-charger.

 

[SteveK]

Jack it all helps to eliminate possibilities. To make sure I have tried everything before hauling it to service.

I know I left invert on standby with AC heaters plugged in that exceed invert capacity when shore power goes out. So I would expect an overload shut down. According to manual, the issue I have is invert not putting out more than 100 volts, solution reduce loads.
I have tried with no load, all AC breakers off and still same fault. Reboot several times holding power button, disconnecting + cable, letting sit with no input AC or DC. All same fault F1 AC Output under voltage.
BTW the breaker for AC output I realized if tripped would also stop the switch from passing through shore power.
This morning the batteries are charged. sitting at 13.8, measured with + disconnected, so no issue with battery output.
Thanks to all.