RCDRCCB

RCDRCCB is a term used to describe a protective device that combines residual current protection with circuit-breaking functionality in a single unit. In practice, it is often used interchangeably with RCBO or described as an RCD with integrated overcurrent protection. The device is designed to protect people from electric shocks by detecting leakage currents to earth and to protect electrical circuits from damage due to overloads or short circuits.

How it works: The device monitors the current flowing through the live and neutral conductors. Under normal operation, these currents are equal. If leakage to earth causes an imbalance beyond a predefined threshold (for example 30 mA for personal protection), the device trips and isolates the protected circuit. At the same time, the unit provides overcurrent protection, disconnecting the circuit during overloads or short circuits. Many models are multi-pole and suitable for single- or multi-phase installations, with variants offering different sensitivity, response times, and breaking capacity.

Standards and types: RCDRCCB-compatible devices are commonly described under standards such as IEC 61009 for residual current devices with overcurrent protection, and IEC 60898 or related standards for circuit-breaker components. They are available in various configurations (2P, 4P, different pole counts) and current ratings, with common sensitivity ratings including 30, 100, or 300 mA for residual current protection and multiple ampere ratings for overload protection. Types may be categorized by tripping characteristics (e.g., instantaneous vs. delayed) and by wave-form response (AC, A, or B, depending on theLoad requirements).

Applications and considerations: These devices are widely used in domestic, commercial, and industrial electrical installations to consolidate protection in a single device, saving space in distribution boards. Installation should follow local electrical codes, ensure correct rating and breaking capacity, and include regular testing. Limitations include higher cost and the potential for nuisance tripping in certain installations.

See also: RCCB, RCBO, residual current device.