... monitoring and relay dry contact.Static transfer switch (STS)It increased the system availability and ... the inverter fails, the line will switch to AC main. The transfer time is less than ... is always connected to AC main and will switch to inverter when AC main fails. The transfer ... , 110VDC, 220VDCOperating range.-18% - +25%AC OutputOutput power1KVA,2KVA, 3KVAWave formPure sine wavePower factor0 ...