RCCB/ELCB/RCD

A KRIPAL Residual Current Device (RCD) is a life-saving electrical safety device designed to prevent electric shock and electrocution. It continuously monitors the electric current flowing in and out of a circuit.

If it detects an imbalance, indicating that current is leaking to earth (e.g., through a person), it instantly cuts off the power within milliseconds. This rapid response is crucial for preventing serious injury or fatalities caused by electrical leakage in both industrial and household environments.

The RCD type defines the kind of fault currents it can detect. KRIPAL offers different types to match modern electrical loads:

• Type AC: The standard type, designed to detect alternating sinusoidal leakage currents. Suitable for traditional resistive and inductive loads (e.g., incandescent lighting, simple motors).
• Type A: A more advanced type that can detect both sinusoidal AC and pulsating DC leakage currents.

This is now highly recommended for most applications, as it protects against faults from modern electronics like variable-speed drives, EV chargers, and appliances with SMPS power supplies (e.g., computers, TVs).

The sensitivity (IΔn) is the level of leakage current that will cause the RCD to trip.

Choosing the right sensitivity is key to the intended protection:

10mA & 30mA - For Personal Protection: These high-sensitivity RCDs are for protecting people. The 30mA sensitivity is the international "safety threshold" and is the standard for most socket outlets, especially in high-risk areas like bathrooms, kitchens, and gardens. 10mA offers even higher sensitivity for areas of extreme risk.

100mA, 300mA & 500mA - For Fire & Equipment Protection: These medium-sensitivity RCDs are primarily used to protect against fire risks caused by persistent earth leakage, which can generate heat. They are used for circuit protection in industrial settings or for large equipment, helping to prevent nuisance tripping from minor, non-hazardous leakage.

KRIPAL provides a comprehensive range of RCDs, including series like UKF7, UKNT50L, and DZ47LE-100, to suit various installation and panel requirements. These series are engineered to deliver reliable earth leakage protection across different applications, from residential consumer units to industrial distribution boards. The specific choice of series depends on factors like physical size, mounting style, and required current rating.

A current as low as 30mA passing through the human body can cause muscle paralysis, preventing a person from letting go, and can be fatal if sustained. A 30mA RCD is designed to be so sensitive that it will detect this small leakage and cut off the power in less than 0.1 seconds. This incredibly fast reaction time prevents the current from reaching a dangerous level or duration, making it the cornerstone of personal electrical safety.

For maximum personal protection, 30mA KRIPAL RCDs should be installed on circuits that supply:

• All general-purpose socket outlets (e.g., in living rooms, bedrooms).
• Bathrooms (for shaver sockets and lighting).
• Kitchens and utility rooms (for appliances and sockets).
• Outdoor sockets, garages, and workshops. Many national wiring regulations now mandate such installations.

A 100mA or 300mA RCD is not a direct replacement for a 30mA device for personal protection.

Instead, it is used for:

Fire Prevention: Protecting entire sub-circuits where the cumulative, normal leakage of multiple devices might cause a lower-sensitivity RCD to trip unnecessarily (a "nuisance trip").

Selective Coordination (Backup Protection): Installing a time-delayed 100mA/300mA RCD upstream of 30mA RCDs. This ensures that if a fault occurs, only the 30mA RCD closest to the fault trips, isolating the problem without cutting power to the entire building.