... to indicate relative parameter,such as AC,DC,Voltage,power synchronous volume,frequency,expended voltage and overload current etc.The product performance ... ,2.5;Service condition:-20~+50°C;Relative humidity:≤85%;Resistance to pressure:when self-frequency constant value various is ±15 ... 450V 500V 600V,More than 600 external connect secondary grade100V voltage transformer