... alternators 2)CLASS H insulation3)IP21/IP23 protection 4)self-regulator by AVR 5)50hz ... touch buttons.Main Functions:1- Display loading power, voltage, currenct, frequency, speed, temperature, oil pressure, ... voltage, low or high frequency, over current, over or low speed, low or over battery voltage etc.3Over load protection, over/under frequency protection, over/under/imbalance voltage protection ...