As industrial automation and commercial power environments grow increasingly complex, traditional electrical protection solutions face unprecedented challenges. How can multi-layered protection for personnel, equipment, and systems be achieved within limited distribution space? In response, ONESTO introduces the KRCT-63 Series 3P RCBO (Residual Current Breaker with Overcurrent Protection).

Working Principle:

The KRCT-63 integrates the dual functions of Miniature Circuit Breaker (MCB) and Residual Current Device (RCD):

Residual Current Protection: An internal high-sensitivity transformer monitors the vector sum of currents between phase lines and the neutral line in real-time. If an earth leakage or electric shock exceeds the preset threshold, the device cuts off the circuit within milliseconds.

Thermal-Magnetic Protection: When the circuit experiences an overload (thermal trip) or a short circuit (magnetic trip), the mechanical structure acts instantly to prevent cables and equipment from being damaged by abnormal high temperatures or electric arcs.

Product Applications:

Triple safety protection (core function)

Anti-Shock (Life Safety): Monitors leakage. If an equipment shell becomes live or a person touches a live part, it cuts power in milliseconds to prevent fatal electric shocks.

Fire Prevention (Electrical Safety): Monitors micro-leakage caused by damaged insulation—a common hidden cause of electrical fires. The RCBO identifies and trips before disaster strikes.

Burnout Prevention (Equipment Protection): Functions as an MCB. When excessive load or a severe short circuit occurs, it cuts power instantly to prevent cables from scorching and equipment from being destroyed by high currents.

Specifically Designed for 3-Phase Environments

Standard leakage protectors are often 1P or 2P (for single-phase residential use). The 3P+N specification is purpose-built for industrial and commercial three-phase power systems. It simultaneously monitors the current vector balance across three phase lines (and the neutral), making it ideal for high-power three-phase machinery.

About ONESTO KRCT-63:

Key Technical Parameters

Rated Current (In): 6A to 63A, meeting demands from precision instruments to heavy-duty power systems.

Poles: 3P+N (for 3-phase 4-wire systems), ensuring synchronized monitoring of all phases and neutral.

Rated Voltage (Ue): 400/415V AC, engineered for industrial and commercial 3-phase environments.

Rated Breaking Capacity (Icn): 10kA (Industrial/Heavy-duty grade), offering superior safety and durability.

Rated Residual Current (IΔn): Available in 10mA (medical-grade safety), 30mA (standard life safety), and 100mA/300mA (fire/equipment protection).

Storage Temperature: -25°C to 70°C (Extreme weather resilient).

Tripping Characteristics: B, C, and D curves to balance lighting and inductive motor loads.

Standard Compliance: Strictly adheres to IEC/EN 61009-1 international standards.

Why Choose ONESTO KRCT-63?

【EV Sector Ready】Type A Anti-Interference Protection

Designed for EV charging piles and solar PV systems. It detects not only standard AC leakage but also pulse DC interference generated by EV chargers and inverters, significantly reducing nuisance tripping. It is the professional choice for 11kW/22kW 3-phase charging systems.

【Medical-Grade Safety】10mA Ultra-High Sensitivity

Unlike the industry standard of 30mA, ONESTO offers an ultra-sensitive 10mA level. It cuts off power before a person feels a strong electric shock, making it ideal for precision laboratories, schools, and hospitals.

【Industrial Strength】10kA Heavy-Duty Breaking Capacity

With a 10,000A (10kA) breaking capacity and a precision arc-extinguishing system, it ensures contacts won't weld and the shell won't rupture during extreme short circuits, providing a robust shield for expensive industrial assets.

【Phase-Independent Logic】Redundant Power Supply

Our advanced logic breaks the dependency on a single L+N supply. It supports power intake from any combination of L/L/L. Even in extreme Lost Neutral or Phase Failure scenarios, the residual current protection remains active, eliminating safety blind spots.

【Global Weather Resilience】 -25°C Cold & 55°C Heat Performance

 Certified with the "Snowflake ❉" mark for extreme cold, ensuring precise tripping from -25°C to 55°C. With a 70°C storage rating and V0-grade flame-retardant materials, it is perfect for outdoor EV chargers in any climate.

Professional Selection Guide

1. Tripping Curves (B, C, or D)

B Curve (3-5 In) - Ultra Sensitive: For electronics, IT server rooms, or very long cable runs where short-circuit current might be low.

C Curve (5-10 In) - General Purpose: Recommended for EV Chargers, office lighting, commercial AC, and standard motors.

D Curve (10-20 In) - Heavy Industrial: For high-inrush loads like large transformers, heavy motors, or welding machines.

2. Rated Current (In)

6A - 16A: For control circuits or precision instruments.

20A - 40A: For 7kW/11kW EV chargers (32A is the industry standard) and commercial AC.

50A - 63A: For 22kW EV chargers and high-power industrial motor distribution.

3. Residual Current (IΔn)

10mA (Medical/High Safety): For hospitals, schools, commercial kitchens, or wet production environments.

30mA (Standard Safety): Mandatory for EV chargers and general office/industrial sockets.

100mA/300mA (Fire Protection): For main distribution boards to prevent insulation-fault fires.

Expert Tip:

For the global EV charging market, the Golden Configuration is: Type A+C Curve + 32A/40A+30mA. This setup is perfectly compatible with most 11kW/22kW 3-phase chargers, ensuring human safety while preventing nuisance trips from DC pulses.

In the field of electrical safety, ONESTO believes that every millampere of precision carries the trust of thousands of families and factories. We don't just provide components; we provide complete power distribution solutions and technical support.

Contact us today for the full catalog and professional power distribution solutions!