Customer T in country K says that Kelong's 6 kVA inverter supplies power properly when the AC input is normal. When the AC input fails, the inverter has no output, and the loads power off. When the mains fails, alarm tones are generated. When the mains is normal, the inverter green indicator is off.
Step 1 The inverter bears only a load power of less than 1 KW, and is not overloaded. Check the input and output carefully, and find no short circuits.
Step 2 Because the inverter indicator is off when the AC input is normal, it is suspected that the inverter has not started. Shut down the inverter and press ON. The inverter transfers to bypass mode. The Bypass indicator is on. About 3 seconds later, the Fault indicator is on in red, and alarm tones are generated.
Step 3 Shut down the inverter, and set the AC input circuit breaker and battery circuit breaker to OFF. Check the inverter working mode, and find that the DIP switch settings are in parallel system mode. In fact, only a single UPS is running. Set the DIP switch to single UPS mode, set the circuit breakers to ON, and restart the inverter. No alarm is generated.
Step 4 Disconnect the AC input. The inverter supplies power properly to the loads.
Check the inverter working mode, and find that the DIP switch settings are in parallel system mode. In fact, only a single UPS is running. This disorders the working logic.