Grounding to prevent the metal shell of the electrical device, the frame of the power distribution device and the line tower from being charged and endangering personal and equipment safety. The so-called protective grounding is a protective wiring method, which connects the metal parts of electrical appliances that are not charged under normal circumstances, but may be charged after the insulation material is damaged or under other circumstances, and the metal structure parts insulated from the charged parts with wires and grounding bodies reliably.
Grounding protection is used in the power supply system (three-phase, three-wire system) where the neutral point of distribution transformer is not directly grounded, so as to ensure that the voltage to the ground generated by the leakage of electrical equipment due to insulation damage does not exceed the safety range.
Extended information 1. Before the product is newly installed, if it is necessary to check whether the leakage circuit breaker can be disconnected, the user must connect the N line (zero line) and the C line (live line) or the N line (zero line) and the A, B and C lines (three live lines) to the incoming line of the product at the same time. Then press the test button with the power off. If the leakage circuit can be disconnected, the product is normal and reliable and can be put into use.
2. After the protector trips automatically, it is necessary to find out the reason and troubleshoot before it can be used.
3. When the leakage circuit breaker is in the closed position or between the outlet terminals, it is forbidden to check the interphase insulation performance to avoid damaging electronic components.
4. When the human body touches two wires on the load side at the same time, the leakage circuit breaker cannot provide safety protection, because the human body actually becomes a load.