An odd behavior is seen on the Deye 8K when the electricians were testing for the CoC.

Basically they turned off the main breaker at the DB to simulate a grid off scenario. The inverter kicked in and started supplying from battery. But the indication light at the main breaker did not go off as it was expected to indicate a grid failure/disconnect. So when they started to troubleshoot, they measured a voltage across the Live and Neutral on the grid input of the Inverter. This seems to indicate that the inverter is not disconnecting itself completely from the Grid Input and is feeding back from power on the input.

The settings (either zero export to Load or zero export to CT) did not seem to make any difference. They had installed a contactor on the Inverter output to bridge Earth and Neutral and when they turn that contactor off, the voltage between L and N on the Grid Input is around 130V. And with L and N bridged it becomes 230V. So it appears the voltage is coming from the inverter when it is off grid and the grid Neutral/Ground has been lost. 

Has anyone else seen this behavior? None of the setting changes on the Inverter seem to make a difference and the 230V is always there, though with very low current since the LED indicator at the DB is On but extremely dim v/s when the grid is actually On.

 

Edited October 24, 20232 yr by narensankar

Sounds like the earth neutral bond wasn't done correctly

4 hours ago, narensankar said:

An odd behavior is seen on the Deye 8K when the electricians were testing for the CoC.

Basically they turned off the main breaker at the DB to simulate a grid off scenario. The inverter kicked in and started supplying from battery. But the indication light at the main breaker did not go off as it was expected to indicate a grid failure/disconnect. So when they started to troubleshoot, they measured a voltage across the Live and Neutral on the grid input of the Inverter. This seems to indicate that the inverter is not disconnecting itself completely from the Grid Input and is feeding back from power on the input.

The settings (either zero export to Load or zero export to CT) did not seem to make any difference. They had installed a contactor on the Inverter output to bridge Earth and Neutral and when they turn that contactor off, the voltage between L and N on the Grid Input is around 130V. And with L and N bridged it becomes 230V. So it appears the voltage is coming from the inverter when it is off grid and the grid Neutral/Ground has been lost. 

Has anyone else seen this behavior? None of the setting changes on the Inverter seem to make a difference and the 230V is always there, though with very low current since the LED indicator at the DB is On but extremely dim v/s when the grid is actually On.

 

Start by removing the grid input to the inverter. With mains off the L to inverter should have zero to N or to E. No volts measured on the non essential output on inverter. 

Some funnies here.