AC clamp meter with a 400A current range and power measurement capabilities. HT4020 measures RMS AC current up to 400 A, AC/DC voltage up to 600 V, frequency, resistance, circuit continuity, active, reactive, and apparent power, Cos₂, and energy for balanced single-phase and/or three-phase systems. It also determines phase sequence using a single-pole method. Each device complies with IEC/EN61010-1 CAT III 600V standards and is ideal for troubleshooting common industrial issues such as nonlinear loads and variable frequency drives.