Overview
EV charging is a safety-critical application, because the charger connects a vehicle to the mains and must detect a fault before it becomes a hazard. The residual current sensor is at the center of that protection, and Hawun supplies the Type B sensors and control supplies that chargers rely on. BeiLuo supplies them as an authorized Hawun distributor with FAE support for charging safety design, including help with the safety chain and its validation.
Why Type B Detection Matters
A residual current sensor detects the small leakage current that indicates an insulation fault, and in an EV charger it must detect both DC and AC residual currents. A DC fault current can appear in charging, and a sensor that only detects AC would miss it, so a Type B sensor is required. A sensor such as the HW-RCS-TYPEB-EV detects both, and it must respond within the time the standard defines while rejecting the noise of the charging environment.
The Safety Chain
The sensor output feeds the charger's controller, which compares it with the threshold the standard defines and trips the contactor on a fault. The sensor, the controller and the contactor form a safety chain, and each link must meet its requirement for the chain to work. The integration should be validated early, because a safety chain is only as strong as its weakest link.
Control Power
A charger needs a low-voltage control rail to run the sensor, the controller and the contactor logic. An enclosed supply such as the HW-AC-ENC-30W-12 provides that rail, and it must be sized for the control load with margin and designed for the charging environment. Because the charger runs continuously in some installations, the supply's efficiency and its thermal design matter as much as its power rating.
Monitoring the Charging Load
Beyond the safety detection, a charger benefits from measuring the charging current for monitoring and control. An AC current sensor such as the HW-RCS-AC-EV measures the load, and its accuracy sets how well the charger can report and control the charge. Pairing the safety sensor with a monitoring sensor gives a complete picture of the charging state.
Standards and Documentation
EV charging is regulated, so the documentation matters. The sensor's certification, its test data and the compliance documents support the charger's safety case, and BeiLuo ships the import, origin and RoHS documents with every order so the paperwork is ready for the audit. The charger must meet the standard for its market, and the sensor must be chosen for that standard.
Why BeiLuo
We hold mainstream Hawun sensors and supplies in regional stock and ship them with import, origin and RoHS documentation. Our engineers support sensor selection, integration and safety documentation review from concept through production, and we can supply samples for bench validation.
Next Steps
Send your charging standard, detection and control requirements and we will propose a sensor and supply set, confirm availability, and supply samples for validation.