3 Phase 4 Wire Meters
3-phase 4 wire meters (10/20, 20/50 A) are used for agricultural and industrial consumers. For loads up to 50 A, the meters are directly linked to the supply. For greater loads, it is preferable to gives CTs. They are rated for 415 V. In a 3-phase 4 wire meter, 3 pairs of coils of every type, i.e., potential coil and current coil are given for each of the three phases. Each of the 3 elements (coil pairs) of the meter produces equivalent torque, i.e., one-third of the total torque under all conditions of varying power factor.