Engineering Guide
GB/T vs IEC leakage protection requirements for AC EV chargers
A map of the IEC and Chinese GB/T standards that govern residual current protection in AC chargers, what they have in common, and how to design one sensor platform for both markets.
Many charger manufacturers sell into both China and export markets. They want to know whether one leakage protection design can serve both, or whether they need separate hardware. The good news is that Chinese and IEC standards follow the same basic logic for AC chargers. This guide maps the main standards against each other and explains what that means for sensor selection.
This guide is a practical overview, not a legal interpretation. Standards are revised regularly, and certification bodies may apply different editions. Always confirm requirements for your specific product and market with your test laboratory.
The shared idea: AC protection plus DC 6 mA detection
In both systems, the hazard is the same. An electric vehicle’s on-board charger can cause smooth DC residual current if insulation fails. Smooth DC can desensitise a common Type A RCD, as explained in Type A vs Type B RCD for EV chargers.
Both IEC and GB/T standards therefore expect the charging system either to use a device that detects smooth DC directly (Type B), or to combine a Type A device with DC residual current detection at 6 mA. That shared “A + 6” concept is why one sensor platform can often serve both markets.
The IEC side
For AC charging in Europe and many other export markets, the main references are:
- IEC 61851-1 – the general standard for conductive charging systems. It requires protection against DC fault current above 6 mA for Mode 3 charging points, using either a Type B RCD or a Type A RCD with a DC detection device.
- IEC 62955 – residual direct current detecting devices (RDC-DD) for Mode 3 charging. It defines the device that adds DC 6 mA detection alongside a Type A RCD. See IEC 62955 RDC-DD explained.
- IEC 62752 – in-cable control and protection devices (IC-CPD) for Mode 2 charging. The portable control box itself must detect AC and smooth DC residual current. See IEC 62752 IC-CPD for Mode 2 chargers.
- IEC 60364-7-722 – the installation rules for EV supply equipment, which set the RCD requirements for the circuit that feeds a charging point. Each country publishes its own national version.
The Chinese GB/T side
For the domestic Chinese market, the corresponding references include:
- GB/T 18487.1 – China’s general standard for electric vehicle conductive charging systems, which plays the same role as IEC 61851-1 and sets the overall safety framework for charging equipment.
- GB/T 40820 – DC residual current detecting devices (RDC-DD) for Mode 3 charging of electric vehicles. It covers the same function as IEC 62955.
- GB/T 22794 – Type F and Type B residual current operated circuit-breakers, with or without overcurrent protection, for household and similar use. It is the reference when a Type B device, or Type B-equivalent detection performance, is part of the design.
Side-by-side map
| Topic | IEC reference | Chinese reference |
|---|---|---|
| Conductive charging system (general) | IEC 61851-1 | GB/T 18487.1 |
| DC residual current detection for Mode 3 (RDC-DD) | IEC 62955 | GB/T 40820 |
| Mode 2 in-cable control and protection device | IEC 62752 | — (check current GB/T requirements for Mode 2 products) |
| Type F and Type B residual current devices | IEC 62423 | GB/T 22794 |
| Installation of EV charging circuits | IEC 60364-7-722 (national versions) | National installation codes |
The structure is similar, but details such as test conditions, test waveforms, marking and the exact edition in force can differ. Those details are where certification surprises usually come from.
Where the practical differences usually appear
When teams adapt one charger for both markets, these are the areas worth checking early with the test laboratory:
- Which edition applies. Both IEC and GB/T documents are revised. A design validated to an older edition may need retesting.
- Test waveforms. Beyond smooth DC and 50 Hz AC, standards test combined and phase-angle-controlled waveforms. EVsense datasheets publish trip currents and trip times for several of these, including smooth DC, 50 Hz AC, half-wave (A0°, A90°, A135°), two-pulse and three-pulse rectified DC, and combined AC + 6 mA DC conditions.
- Product category and installation. Chinese public charging piles and European wallboxes are often installed differently, which affects what the upstream RCD is and what the charger must provide itself.
- Mechanical and environmental requirements. Enclosure, temperature and EMC requirements can affect where and how the sensor is mounted.
Designing one sensor platform for both markets
EVsense Type A + DC 6mA sensors are designed against both IEC references (IEC 62955, IEC 61851, IEC 62752) and Chinese references (GB/T 40820, GB/T 22794). Published typical thresholds are:
- Smooth DC trip current: 3 mA min / 4.5 mA typ / 6 mA max
- AC (50 Hz) trip current: 15 mA min / 22 mA typ / 30 mA max
- Smooth DC 6 mA trip time: 380 ms typical, 650 ms max (1R20 Series datasheet)
Models commonly used for dual-market platforms:
- 5R15Z – used in GB-standard AC charging pile applications; PCB-mounted with a 15 mm aperture.
- 1R20 Series – 20 mm aperture for three-phase Mode 3 chargers, available as harness (1R20X) or PCB-mounted (1R20Z) versions.
- 2R4Z – integrates voltage and current transformers with the residual current detection, for European Mode 2 and Mode 3 designs.
Using the same sensor family in both versions of a charger keeps the firmware, self-test sequence and PCB layout consistent. Only the market-specific parts of the product need to change.
A shared sensor family also simplifies purchasing and quality control. Your incoming inspection, production test fixture and spare-parts stock stay the same, and your engineering team only has to learn one self-test timing sequence. When a standard is revised, you validate the change once rather than for several different sensor designs.
Checklist for a dual-market charger
- List the target markets and the edition of each standard your certification body will apply.
- Decide the protection architecture for each market: built-in Type A + DC 6 mA detection, or a Type B device.
- Choose a sensor designed against both IEC and GB/T references, and check its published test waveforms.
- Follow the same integration rules in both versions (see our PCB integration guide).
- Pre-test the complete charger with smooth DC, AC and pulsating DC residual currents before formal certification.
Need help with a dual-market project? Send us your charger platform and target markets and our engineers will recommend a sensor, share datasheets and arrange samples. You can also compare all EVsense RCD sensors.
Frequently asked questions
What is the Chinese equivalent of IEC 62955?
GB/T 40820 covers DC residual current detecting devices (RDC-DD) for Mode 3 charging of electric vehicles, which is the same function that IEC 62955 covers internationally.
Can one RCD sensor be used for both European and Chinese chargers?
Often yes. EVsense Type A + DC 6mA sensors are designed against both IEC references (IEC 62955, IEC 61851, IEC 62752) and Chinese references (GB/T 40820, GB/T 22794). Final compliance must always be verified in the complete charger against the edition of the standard your certification body applies.
Which EVsense sensor is used in GB-standard charging piles?
The 5R15Z is used in GB-standard AC charging pile applications. It is PCB-mounted with a 15 mm aperture and has the same Type A + DC 6mA trip thresholds as other EVsense packaged sensors.
Need help choosing a sensor?
Send your charger platform, target standard, rated current and PCB space. Our engineers reply with a model recommendation, datasheets and sample options.