Wiring method of three-phase four-wire external transformer energy meter

Turn over the terminal cover and you can see the three-phase four-wire meter wiring diagram. Among them, 1, 4, and 7 are connected to the S1 terminal of the secondary side of the current transformer, which is the current incoming terminal; 3, 6, and 9 are connected to the S2 terminal of the secondary side of the current transformer, which is the current outgoing terminal; 2, 5, and 8 are connected to the three terminals respectively. Phase power supply; 10 and 11 are connected to the zero terminal. For safety reasons, the S2 terminal of the current transformer should be connected to ground. Note that the current measurement sampling of each current transformer must be in the same phase as its voltage sampling, that is, 1, 2, and 3 are a group; 4, 5, and 6 are a group; and 7, 8, and 9 are a group.

Three-phase four-wire electric meter wiring diagram without current transformer

Three-phase four-wire electric meter wiring diagram with current transformer

Wiring diagram of three-phase four-wire electricity meter with transformer