... for VoltageAVRAdjustment Ratio for Voltage±5%Voltage regulation±1%No load voltage waveform<2%WaveformTIF<50 ... and touch buttons.Main Functions:Ø Display loading power, voltage, currenct, frequency, speed, temperature, oil pressure, ... , over current, over or low speed, low or over battery voltage etc.Ø Over load protection, over/under frequency protection, over/under/imbalance voltage protection ...