... ,power synchronous volume,frequency,expended voltage and overload current etc.The product performance is accordance with GB7676-98standard.Main technical parameterAccuracy ... -frequency constant value various is ±15%,The error of indicationg volume isn't more than the basic error;Machinery function:It can ... ,More than 60A external connect 50mV,60mV or 75mV shunt the best quality current meter