EV Charger Protection- RCM

RCM in the context of electric vehicles (EV) refers to Residual Current Monitoring. It's a safety feature used in EV charging systems to detect and monitor leakage currents (residual currents) that might occur due to insulation failures or other faults. These currents can be a safety hazard, potentially leading to electric shocks, so RCM systems are designed to alert users or even disconnect the charging system if a dangerous level of residual current is detected. 

Residual Current Monitor (RCM) detects current leaking outside its normal circuit path. In power circuits, current normally flows only in the phase and neutral wires. Current flowing in the ground wire (or other path to ground) and through the exposed metal parts within the rack, presenting a significant danger for humans is known as leakage current.

The Residual Current Monitor (RCM) range is intended for the detection of DC and/or AC residual currents in AC or DC installations. These RCMs are ideally suited for use with Electric Vehicle charging cables (Mode 2 Protection) and EV charging stations (Mode 3 Protection). Residual current detection options for IEC based requirements are 30mA AC or 6mA DC or both and are 20mA AC & 6mA DC for UL requirements.

Why RCM is important in EV charger protection:

Safety:

EV charging systems, especially in public charging stations, can have high voltages and currents, making leakage currents a serious safety concern. 

Compliance:

Many countries and regions have safety standards, such as IEC 62752 (Mode 2 charging) and IEC 62955 (Mode 3 charging), that require the use of RCMs in EV charging systems. 

Mode 2:IEC 62752 In-cable control and protection device for mode 2 charging of electric road vehicles (IC-CPD).

Mode 3:IEC 62955 Residual Direct Current Monitoring Device to be used for Mode 3 charging of Electric Vehicle.

The Residual Current Monitor (RCM) module is connected in series with the AC supply to an EV and will provide an output if a DC current ≥ 6mA DC flows in the circuit. This output can be used to operate an RCD, a circuit breaker or a contactor to remove the supply to the EV.

Residual Current Monitoring (RCM) can be named as Residual Current Detection (RCD) ,leakage current sensor etc, but all of them are worked for electrical safety especially in the area of EV charger protection. If you need some to detect the small current of AC or DC ,plz contact us for more information.