Precautions for leakage circuit breakers


1. Before installation, check whether the data on the nameplate of the leakage circuit breaker is consistent with the usage requirements.
2. Do not install too close to the high-current bus and AC contactor.
3. When the operating current of the leakage circuit breaker is greater than 15mA, the equipment shell protected by it must be reliably grounded.
4. The power supply mode, voltage and grounding form of the system should be fully considered.
5. When installing a leakage circuit breaker with short-circuit protection, there must be sufficient arcing distance.
6. The external connection control circuit of the combined leakage circuit breaker should use copper wire with a cross-sectional area of ​​not less than 1.5mm².
7. After the leakage circuit breaker is installed, the original grounding protection measures of the original low-voltage circuit or equipment cannot be removed. At the same time, the neutral line of the load side of the circuit breaker shall not be shared with other circuits to avoid malfunction.
8. The neutral wire and the protective ground wire must be strictly distinguished during installation. The neutral wire of the three-pole four-wire and four-pole leakage circuit breaker should be connected to the circuit breaker. The neutral wire passing through the circuit breaker can no longer be used as a protective grounding wire, nor can it be repeatedly grounded or connected to the enclosure of electrical equipment. The protective ground wire must not be connected to the leakage circuit breaker.
9. The protection range of the leakage circuit breaker should be an independent circuit and cannot be electrically connected to other circuits. Leakage circuit breakers cannot be used in parallel to protect the same circuit or electrical equipment.
10. After installation, operate the test button to check whether the leakage circuit breaker can operate reliably. Under normal circumstances, it should be tested more than three times and it can work normally.


1. Wiring should be done in accordance with the power supply and load signs on the leakage circuit breaker, and the two should not be reversed.
2. The protection line must not pass through the zero-sequence current transformer. When the three-phase five-wire system or the single-phase three-wire system is adopted, the protection line must be connected to the protection trunk line at the inlet end of the leakage circuit breaker, and must not pass through the zero sequence current mutual inductance in the middle. Device.
3. For single-phase lighting circuits, three-phase four-wire distribution lines and other lines or equipment that use a working neutral line, the neutral line must pass through a zero-sequence current transformer.
4. In the system where the neutral point of the transformer is directly grounded, once the leakage circuit breaker is installed, the working neutral line can only be used as the working neutral line after passing through the zero sequence current transformer. The working neutral wires of other lines are connected.
5. Electrical equipment can only be connected to the load side of the leakage circuit breaker. One end is not allowed to be connected to the load side and the other end to the power supply side.
6. In three-phase four-wire system or three-phase five-wire system where single-phase and three-phase loads are mixed, try to balance the three-phase load.

Company Profile

Changan Group Co., Ltd. is a power manufacturer and exporter of industrial electrical equipment. We are committed to improving the quality of life and the environment through a professional R&D team, advanced management and effective services.

Tel: 0086-577-62763666 62780116
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Post time: Oct-14-2021