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IEC 62752-2016: In-Cable Control and Protection Device for Mode 2 Charging of Electric Road Vehicles (IC-CPD)
This standard specifies the requirements for in-cable control and protection devices (IC-CPDs) used in Mode 2 charging of electric vehicles. These devices combine residual current protection, overcurrent protection, and control/pilot functions in a single portable assembly integrated into the charging cable between the standard socket-outlet and the vehicle connector.
1. IC-CPD Classification and Functional Architecture
IEC 62752-2016 defines IC-CPDs as essential safety components for Mode 2 EV charging, where the electric vehicle is connected to a standard household or industrial socket-outlet via a cable assembly containing the control and protection device. The standard classifies IC-CPDs by supply configuration (single-phase LNSE/LNE, two-phase LLSE/LLE, or three-phase LLLNSE/LLLNE), by construction (function box separated from plug, integrated with plug, or modular), and by protective conductor handling (switched or non-switched PE).
The IC-CPD integrates multiple critical functions in a single device:
| Function | Description | Standard Reference |
|---|---|---|
| Residual current protection (RCD) | Detection and interruption of sinusoidal AC residual currents, pulsating DC residual currents, and smooth DC residual currents up to 6 mA | Clause 5.2.8 |
| Overcurrent protection | Inverse-time delayed overcurrent tripping characteristic, typically with rated currents of 8 A, 10 A, 13 A, or 16 A | Clause 5.2.2 |
| Control pilot function | Communication with the electric vehicle per IEC 61851-1, including proximity detection, ventilation requirements, and charging current setting | Clause 3.3.7 |
| Short-circuit protection | Making and breaking capacity of a rated conditional short-circuit current (Inc) with coordination to upstream SCPD | Clause 5.3.10 |
| Open PE conductor detection | Optional verification of upstream protective conductor continuity before enabling charging | Clause 4.5.2 |
A critical distinction: IC-CPDs classified as Type A detect AC residual currents and pulsating DC residual currents. For Mode 2 charging, the IC-CPD must also handle smooth DC residual currents that may arise from onboard charger rectifier stages, requiring Type F or Type B RCD characteristics or additional DC detection per IEC 62955.
2. Electrical Performance Requirements and Test Conditions
The standard establishes stringent performance requirements for IC-CPDs under various operating conditions. The rated operational voltage covers the most common global supply voltages: 100 V (50/60 Hz), 120 V (50/60 Hz), 200 V (50/60 Hz), 230 V (50/60 Hz), and 277 V (50/60 Hz), with specific test parameters defined for each voltage level.
Break time limits are specified for residual current operation. For sinusoidal AC residual currents at IΔn, the IC-CPD must trip within 300 ms. For pulsating DC residual currents, the maximum break time is 300 ms at 1.4 × IΔn. For smooth DC residual currents, a separate detection threshold is set at 6 mA DC with a 10-second maximum response time.
The standard specifies 5.3.4 non-operating overcurrent requirements: the IC-CPD must not trip for a continuous overcurrent of 1.13 × In and must trip within 2 hours for 1.45 × In, consistent with conventional overcurrent protection characteristics.
| Test Parameter | Single-Phase (230 V) | Two-Phase (LLSE) | Three-Phase (LLLNSE) |
|---|---|---|---|
| Rated current (In) | 8/10/13/16 A | 16 A | 16/32 A |
| Rated residual current (IΔn) | 30 mA | 30 mA | 30 mA |
| Conditional short-circuit (Inc) | 6 kA | 6 kA | 10 kA |
| Rated making/breaking (Im) | 10 × In | 10 × In | 10 × In |
| Rated residual making/breaking (IΔm) | 250 A | 250 A | 250 A |
| Impulse withstand voltage | 4 kV (1.2/50 μs) | 4 kV | 6 kV |
Engineering Insight: The IC-CPD must coordinate with the upstream overcurrent protective device (SCPD) under short-circuit conditions. The energy let-through (I²t) of the IC-CPD must be lower than the withstand capability of the cable assembly. For typical 2.5 mm² charging cables with PVC insulation, the maximum permissible I²t is approximately 60,000 A²s. Designers should verify this coordination across the full temperature range (−25 °C to +40 °C).
3. Mechanical Design and Environmental Durability
IC-CPDs must withstand the demanding environment of portable EV charging, including cable flexing, impact, temperature extremes, and moisture ingress. The standard specifies a comprehensive suite of mechanical tests:
Cable bending and pull-out tests subject the IC-CPD to 10,000 flexing cycles at a specified bending angle to verify reliable connections. The strain relief must withstand a pull force of 200 N without displacement. For the plug connector, a minimum of 100 insertion/withdrawal cycles is required without degradation of protective conductor continuity.
Thermal tests verify that the temperature rise of accessible parts does not exceed 60 K above ambient under rated load conditions, while internal components must not exceed their rated temperature limits. The IC-CPD must operate reliably across an ambient temperature range of −25 °C to +40 °C, consistent with outdoor installation requirements.
For enclosure protection, IC-CPDs intended for outdoor use must achieve minimum IP44 (protection against solid objects >1 mm and splashing water). Wall-mounted units must achieve IP54. The standard also requires that the IC-CPD be resistant to UV exposure and to common automotive fluids including gasoline, diesel, and battery acid.
A frequently overlooked requirement: The IC-CPD must continue to provide residual current protection even when the upstream socket-outlet has no protective earth conductor connected (TN/TT systems) or when the PE conductor is interrupted. For IC-CPDs with PE continuity verification (Type B PE monitoring), the device must prevent charging within 10 seconds if the PE path resistance exceeds 100 Ω. This is a critical safety feature for portable charging in older installations.
4. FAQs
Q: What is the difference between an IC-CPD and a standard RCD?
A: An IC-CPD integrates RCD, overcurrent protection, and EV control pilot functions in a single portable device. Unlike fixed RCDs, IC-CPDs are designed for portable use with cable flexing, provide EV-specific communication (proximity pilot, control pilot per IEC 61851-1), and include DC residual current detection for modern EV onboard chargers with rectifier stages.
Q: Can an IC-CPD be repaired or has replaceable parts?
A: Per clause 8.3.2, IC-CPDs are generally non-rewirable and non-repairable devices. The cable entry must be sealed to prevent tampering. Any damage to the IC-CPD or its cable assembly requires complete replacement. This ensures that the original type-test validation remains applicable.
Q: How does the control pilot function work in the IC-CPD?
A: The IC-CPD generates a ±12 V PWM signal on the control pilot (CP) pin per IEC 61851-1. The duty cycle encodes the maximum available charging current (e.g., 50 % duty = 32 A). The vehicle responds by modulating the voltage level through a resistor network, indicating connection state (A/B/C) and ventilation requirements.
Q: What are the marking requirements for IC-CPDs?
A: Clause 6.1 requires permanent marking including rated voltage/current, IΔn, Inc, manufacturer identification, date code, type reference, and the IC-CPD symbol. Additional markings must indicate the intended EV charging application, temperature range, and certification marks. All markings must remain legible after abrasion testing per clause 6.1.
