... 4.copper transformer 5.isolated transformer Feature:*IGBT/SPWM,small volume,lower noise,high reliability*double isolation of the input ... 20%Output voltage:115V±20%Reactime:≤2msDigital meter indication:Frequency,voltage,current,power and power factor meterWorking temperarure:-28 ... warning devicescooling system:Forced fan cooling 3KVA 400HZ frequency converter medium frequency power supply for aircraft