... SPWM pulse-width modulation technology, the output of changhong inverter is CVCF (constant voltage& constant frequency), noise filtering ... can be monitored through its indicator on the inverter.Changhong Inverter technical data sheet ModelCH48/220-3KVAAC OutputRated ... rated load, 30sIsolationPRI-SEC: 2000 VAC, 1min, 10mAPRI-GND: 2000 VAC, 1min, 10mASEC-GND: 2000 VAC, 1min, 10mANoise1m<40dBOperating ...