fluxgate current sensor HYCA-16-PD (RDC)

Residual current discharge (RCD) is now a key safety/compliance risk for modern PV systems.

Long cables, complex grounding, grid/off-grid switching and EMI filters create mixed AC/DC leakage that, if unmonitored, can cause shock, equipment damage, fire and delay inverter certification.

Our HYCA-16-PD (RDC) fluxgate sensor delivers zero-sequence, high-speed AC/DC residual monitoring with digital anti-shake and fast trip—plug-and-play via 5 V supply, board-mount design, self-test/cal, and high/low outputs for MCUs, relays/contactors, breakers, or solid-state switches.

What are the pain points and trends in photovoltaic applications?

Long lines high-frequency interference:

Long-distance wiring and routing from system components to inverters, EMI filtering and grid-connected harmonics all contribute to the superposition of multi-spectral residual currents.

DC-side sensitivity:

Because PERC/TopCon/HJT components and energy storage are connected in parallel, fluxgate current sensor are significant.

Traditional current sensors, sensitive only to AC, such as RCD monitoring, are naturally incapable of addressing this issue.

Compliance certification:

As the market matures, fluxgate current sensor testing for combined AC/DC residual currents becomes more stringent, requiring lower thresholds, faster operation, and stronger anti-vibration capabilities.

System integration:

PV inverters, energy storage, and charging stations are clearly trending toward integration.

Sharing RCD monitoring bases can reduce BOM costs, improve system consistency, and enhance maintenance efficiency.

 

Why choose HYCA-16-PD (RDC)？

（1) Full AC/DC waveform coverage, taking into account both sensitivity and anti-false operation

The typical operating threshold at AC 50 Hz is approximately 22 mA (range 20–26 mA), meeting the requirements for personal electric shock protection and system fire protection.

Fluxgate current sensor DC residual action threshold is about 4–5 mA (typical value is 3–5 mA for different working conditions, such as S-DC/2PDC/3PDC), covering sensitive scenarios on the PV DC side.

The F waveform, A0/A90/A135 and other composite waveforms all have clear response windows, taking into account the mixed spectrum under real working conditions.

Digital hysteresis:

The action threshold is 100% of the typical value, and the recovery threshold is approximately 55% of it, effectively suppressing “saw-trail” false operations caused by small fluctuations.

（2) Act quickly to maintain the system’s “golden 100 ms”

Typica 50–100 ms operation at 30 mA AC;

For high fault currents (5–100 A), the response time can be as low as 8.5–12 ms, quickly linking the upper-level disconnecting unit to reduce thermal/energy shock.

（3) Simple hardware interface, easy to integrate with inverter/energy storage controller

5V single power supply (4.85–5.15 V), power consumption ≤ 110 mW, friendly to system power budget;

TRIP high and low level output, directly fed to MCU or logic/driver unit;

One-button zero drift calibration on the CAL pin adapts to changes in ambient temperature, magnetic field, and installation tolerance;

The TEST pin has a built-in self-test function, which can perform an online health check with a typical 6.53 mA DC analog residual voltage upon power-up, facilitating factory delivery and routine inspections.

Provides timing recommendations (T1–T5 windows for power-on, calibration, and self-test) to guide projects through rapid device consistency verification.

（4) Wide temperature range and long life, suitable for harsh outdoor scenes

-40°C ~ +85°C operating temperature, ≤95% RH, altitude ≤4000 m;

The theoretical design life is ≥20 years, matching the photovoltaic system life cycle requirements.

（5) Standards Adaptation for Compliance

Fluxgate current sensor is compatible with residual current detection requirements such as IEC 62955 (RDC-PD) and IEC 62752.

In integrated photovoltaic scenarios, it can serve as an AC/DC-sensitive RCD monitoring base, helping the system more easily integrate with the target market’s compliance framework and type test procedures.

Typical photovoltaic solutions implemented

1.Grid-connected string inverter/central inverter

Establish hierarchical RCD detection points at the DC bus, DC/AC main conversion, and grid-connected sides:

DC combiner box side:

monitor the residual current on the array side and cut off the branch circuit immediately;

Inside the inverter:

Linked with the main control MCU to achieve rapid disconnection of TRIP → relay/circuit breaker;

Grid-connected side:

Coordinate with existing RCD/RCBO to reduce false tripping.

Combined with the digital hysteresis and fast action of HYCA-16-PD, it reduces false alarms caused by rain, fog, long cable capacitance and EMI disturbances.

Integrated photovoltaic storage and charging (PV+ESS+EV)

The charging side often requires a sensitive detection capability of DC 6 mA.

And HYCA-16-PD supports DC operating conditions such as S-DC/2PDC/3PDC, and unifies the RCD monitoring platform with the energy storage BMS/charging controller, reducing BOM and maintenance costs with a single device.

Microinverter/Residential Inverter

(1)The miniaturized onboard design, ≤110 mW power consumption, and 5 V power supply make it ideal for space-constrained micro inverters and household appliances.

(2)Self-test and self-calibration facilitate batch installation and remote maintenance.

Integration and Verification Recommendations

Power supply and timing:

(1)The power-on slope should be ≤5 ms/V. A stabilization time of T1 ≥100 ms is recommended.

(2)Zero-phase calibration begins when the CAL low level is ≥50 ms.

(2)After calibration is complete, perform a TEST self-test (T4 ≈ 400 ms) to ensure self-test coverage.

Linkage logic:

Connect TRIP to the MCU or hardware interlock channel and connect to the contactor/circuit breaker;

the action holding time T5≈T4 is convenient for reliable identification by the superior.

Structure and EMC:

Transformers should be placed away from high-current busbars and power magnetic components as much as possible;

differential mode is preferred for routing, and the input reference ground should be reliably connected at a single point.

Routine maintenance:

Use the TEST pin to inject 6.53 mA DC residual current during startup or maintenance to complete the “health self-check” and log the entire machine.

OEM customization capabilities (born for photovoltaics)

Threshold and waveform strategy:

fine-tune the action/reset threshold and waveform sensitivity configuration according to the target market and type test requirements, balancing low false trip rate and high safety margin.

Mechanical|Interface:

(1)Window size, pin definition and connector form can be customized and are compatible with multiple main control platforms;

(2)shielded housing or potting versions are available to enhance environmental adaptability.

System-level support:

Providing prototypes and design references (timing, linkage, and calibration processes) to help inverter/energy storage/charging integrated devices pass third-party testing and certification more quickly.

Choosing the HYCA-16-PD (RDC) as the RCD safety mount for your photovoltaic system means you’ve achieved the optimal balance between personal and property safety, regulatory compliance, system availability and lifetime cost.

Leveraging our extensive expertise in high-precision instrument transformers and OEM customization, you can more quickly make safety the “default configuration” and focus on optimizing power generation efficiency and cost per kilowatt-hour.

Welcome to contact and consult at any time！

Compay：HEYI Electrical Co., Ltd.

Brand: HEYI/ASCT

Contact: Bethy

E-mail: heyi@heyiele.com             

Tel: 86-13968747975

 

 

--- END ---