... 600 V CAT2) Power measurement of 3-phase 3-wire, 3-phase 4-wire, single-phase mode 3) V, A, W, ... and select tested signal be power supply for the clamp at one time, the instrument can ... serious, it is better to use manual settings for testing frequency so as to assure the reading ... °C ~ 28°C, Humidity 80%, frequency for voltage, current: 45 Hz ~ 65 Hz Three Phase Digital Power Clamp Meter