Technical Support

Our client, in South Africa, has a generator connected to 2 x parallel 8 kW Sunsynk inverters. The "Signal Island Mode" is not ticked as the system is connected to the grid. We have connected the generator start contact across terminals 7 and 8, to start the generator, on the Master Inverter only, as per the Sunsynk manual, when the batteries are down to a set level of 25% SOC. On testing we find that this contact is closed irrespective of the battery SOC, which means that the generator starts even when the battery SOC is, say 80%, if the mains supply gets lost. We have tested this in practice and this is what is happening. That contact is supposed to be normally open and to close only when the SOC goes down to the set battery level, which is 25% in our case. Above that it must remain in the open position, so that the generator doesn't start. There is permanent neutral-to-earth bonding.

The Settings are as follows:

A) With respect to the Battery Settings, we have ticked Gen Charge, set Gen Start % to 25% and set Gen Amps to 3A (which is set this low because the generator size is not big enough to supply both the load and a higher level of battery charging, once the grid gets lost and there is no solar supply). We have also ticked Grid Signal, Gen Signal and Gen Force. Signal Island Mode is not ticked, as mentioned earlier.

B) On the Auxiliary Load setting page, we ticked Gen Input and set On/(Start) % to 25%, as mentioned earlier and Off/(Stop)% to 95%

C) Under System Mode we have ticked both Grid Charge and Gen Charge, as well as Use Timer. The Time 1, Time 2...to Time 6 are all ticked for both Grid Charge and Gen Charge. The Grid/Gen Charge SOC% setting is set to 60%, for all the 6 timers.

What do we need to do get correct operation?