IEC 62955 vs IEC 62752: Understanding the Key Differences in EV Charger Standards

What Are IEC 62955 and IEC 62752?

These two key international standards define how residual current detection should be implemented in EV charging infrastructure:

• IEC 62955:2018 – Residual direct current detecting device (RDC-DD) to be used for mode 3 charging of electric vehicles

• IEC 62752:2016 – In-cable control and protection device (IC-CPD) for mode 2 charging of electric vehicles

Understanding the differences between these two standards is essential to ensure product compliance, functional safety and optimal user experience.

IEC 62955: For Fixed Mode 3 EV Charging Stations

IEC 62955 applies to RDC-DDs (Residual Direct Current Detecting Devices) used in Mode 3 EVSE—typically fixed wall-mounted or pedestal chargers connected to the AC grid via a dedicated circuit.

Key Requirements: 

• DC Residual Current Detection Threshold: Must trip at ≥ 6 mA of smooth DC residual current
• AC Fault Immunity: As defined in Clause 6.2.1.2, the RDC-DD must not trip on pure sinusoidal AC residual currents up to 30 mA
• Intended Coordination: Designed to work in conjunction with upstream Type A or Type F RCDs, which handle AC and pulsating DC faults

This separation of responsibilities prevents nuisance tripping and ensures proper fault coordination between the RDC-DD and the upstream RCD.

IEC 62752: For Portable Mode 2 Charging Cables

IEC 62752 covers IC-CPDs (In-Cable Control and Protection Devices), used in Mode 2 charging where the EV is connected to a standard household or industrial outlet using a portable charging cable with built-in protection.

Key Characteristics: 

• Integrates both AC and DC residual current detection into a compact, portable device

• AC trip thresholds typically range between 20–30 mA, depending on the manufacturer’s design

• Designed to provide standalone protection without the need for upstream RCDs

Since IC-CPDs are connected to general-purpose sockets, they are required to offer complete protection—including detection of both AC and DC faults—within the device itself.

Why This Distinction Matters

For Product Designers and Compliance Engineers: 

• Selecting the wrong standard can result in non-compliance, unnecessary tripping, or even safety gaps

• IEC 62955-compliant RDC-DDs must ignore harmless AC leakage and only act on smooth DC faults, to ensure correct operation alongside upstream RCDs

• IEC 62752-compliant IC-CPDs must handle both AC and DC leakage independently, as they’re often the sole protection device

For OEMs and Charging Manufacturers: 

• Meeting the right standard ensures smoother certification processes, fewer field issues, and better customer satisfaction
• It also aligns your product with the expectations of grid operators, utility companies, and regulators—especially in Europe and other regions adopting harmonized standards

Summary: Which Standard Do You Need?

Conclusion

If you are developing or installing EV charging equipment, selecting devices compliant with IEC 62955 or IEC 62752 is essential for safety and regulatory compliance.

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