The principle of leakage protection for DC EV Charger

2026,10,26

DC EV Charger have built-in leakage protection, which is one of the most important defense lines for charging safety. It is used to monitor abnormal leakage current in the circuit. Once the leakage reaches the threshold, the power supply will be cut off in milliseconds to prevent electric shock accidents.

Integrated DC High‑Speed Charging Cabinet

DC EV Charger leakage protection is divided into type A leakage protection and type B/DC6mA leakage protection. It is recommended to use a protection device with DC leakage detection for DC EV Charger.

Ordinary household socket leakage protectors can only detect AC leakage, and there is a DC component in the power battery charging circuit. Ordinary leakage protectors cannot identify it and do not trip in case of faults, posing a safety hazard.

Before starting the DC EV Charger for charging, the equipment will automatically perform insulation testing to check the insulation resistance of the DC EV Charger, cables, and charging gun to ground. If the insulation drops and there is a risk of leakage, charging is directly prohibited.

Continuously monitor the insulation status in real-time throughout the charging process. Once the insulation deteriorates, immediately shut down and cut off the power, while reporting a fault code. The leakage protection device will conduct regular self checks to ensure effective protection.

Many car owners are puzzled whether the grounding of DC EV Charger is related to leakage protection. Good grounding is a prerequisite for the normal operation of leakage protection. If the grounding fails, the effectiveness of leakage protection will be greatly reduced. Reliable grounding must be ensured during the construction phase, and the grounding resistance must meet the requirements of the specifications.

Leakage protector is a consumable device, and its protection deteriorates with the increase of service life. It is recommended to conduct electrical testing annually for public DC EV Charger, and manually test the leakage protection button for DC EV Charger on a regular basis.

Leakage protection cannot avoid all electrical risks. Aging and damage of cables, as well as unauthorized modification of circuits, can still pose safety hazards. It is strictly prohibited to modify the internal circuits of DC EV Charger without authorization.

Author:

Mr. yjfastener

E-mail:

hou@citool.com

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