News | company news | Aug 19,2025
HYCA-16-PD (RDC) residual current sensor by HEYI
Product positioning and standard adaptation ?
for electric mobility scenarios such as AC EV charging piles/ DC fast EV charging piles is used to quickly issue a trip signal when leakage current occurs, driving the upper circuit breaker or relay to cut off the power supply.
The residual current sensor requires IEC 62752 and IEC 62955 (RDC-PD) apply, and the device is ROHS/REACH compliant.
What is the core selling point of residual current sensor HYCA-16-PD ?
Sensitive to all AC+DC waveforms:
Detects 50 Hz AC, superimposed DC, and pure DC (such as S-DC and 2PDC/3PDC).
Typical DC trigger levels are approximately 4–5 mA, meeting the industry consensus threshold of 6 mA DC protection for EV charging equipment.
Fast action:
Typical action time is 16–50 ms at 30–60 mA AC, and typical action time is ~8–12 ms for severe faults (≥5 A), balancing safety and false trip rate.
Complete self-test/zero calibration:
Supports zero calibration pin (CAL) and self-test pin (TEST) processes after power-on.
By injecting two turns on the ZCT, using a typical simulated 6.53 mA DC for routine checks before shipment and power-on to avoid “dumb protection“.
Easy integration:
Single +5 V power supply (4.85–5.15 V), TRIP pin outputs TTL high level (≥4.2 V) for direct connection to MCU/relay drive chain; total power consumption ≤110 mW.
Environment and lifespan:
Operating temperature:
−40°C to +85°C, humidity: 95% RH, altitude ≤ 4000 m, theoretical design life ≥ 20 years, suitable for outdoor pile and heavy-load environments.
Trigger current threshold (50 Hz):
Pure AC: approximately 22 mA (20–26 mA range)
Class A phase variants (A0/A90/A135): 15–24 mA level
S-DC/2PDC/3PDC: ~4–5 mA
Class F: ~24 mA level
The action threshold setting is equipped with hysteresis:
the reset threshold is approximately ~55% of the trigger value, which can significantly suppress chattering and false resets.
Action time:
AC 30 mA: 50 ms typical
AC 60 mA: Typical 16 ms
DC 6 mA (S-DC): Typical 48 ms (upper limit 1 s, depending on waveform and system noise)
High current (5–100 A): 8.5–12 ms typical.
Pins and power-on timing:

The VDD rising slope should be ≤ 5 ms/V. It is recommended to wait for T1 ≥ 100 ms after powering on. After CAL is low for ≥ 50 ms, enter zero-phase calibration (T3 ≥ 500 ms), then perform a TEST self-test (~400 ms). The TRIP high level should remain T5 ≈ T4. The power supply ripple is recommended to be ≤ 150 mV.
Integration and design recommendations (engineering perspective)
Power integrity:
5 V voltage regulation requires a margin of ≥100 mA. Place low-ESR capacitors and π filters near the input to ensure that the ripple is <150 mV to reduce threshold drift.
Sequence execution:
Strictly follow the process of power-on → zero calibration → waiting → self-test → charge enable, and incorporate the self-test judgment into the EV charging enable condition of the BMS/master control.
Hysteresis recognition:
Since the reset threshold is approximately 0.55×I_trip, the system may maintain a high level for a period of time under the boundary leakage waveform before resetting. Logically, debouncing and requiring state machine judgment.
Interface matching:
TRIP signal is valid at high level. If the upper level is valid at low level or requiring open drain, inversion/isolation can be done at the board level.
Scenario expansion:
In addition to AC EV charging piles, you can use it for leakage monitoring of battery swap warehouses/lithium battery charging cabinets/industrial power supplies/inverters and photovoltaic storage converters.

Comparison Summary:
Compared to AC-only sensitive RCD solutions, the HYCA-16-PD can quickly issue an alarm in the event of DC leakage (such as OBC/PFC rectifier failure).
Self-test and zero calibration ensure production consistency and installation reliability, which is particularly critical for public charging piles.
Combined with your company’s “high-precision + OEM customization” capabilities, we can further customize the structural form, connection terminals, mounting method, signal interface, and self-test strategy to shorten the overall system introduction cycle.
Compay:HEYI Electrical Co., Ltd.
Brand: HEYI/ASCT
Contact: Bethy
E-mail: heyi@heyiele.com
Tel: 86-13968747975
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