These devices are used for the protection of electrical circuit from issues such as overcurrent, and short circuit. Combined with other equipment they can also protect the system from other issues such as over/under voltage and phase lost. Here we have resources and product details for these protection devices. The devices are separated into different categories ranging from Low Voltage (under 1,000 Vac), Medium Voltage (1-7.2kV), and High Voltage (over 7.2kV).

Circuit Breakers

The popular and common device circuit breakers are used in almost every building. Residential typically use the Miniature Circuit Breakers or MCB for short. While Commercial buildings require larger protection devices such as the Molded Case Circuit Breaker (MCCB) or the Air Circuit Breaker (ACB). MCB is generally used up to 100A while MCCB for a bigger requirement.

The choices for Choosing between ACB and MCCB are normally decided from the rated short-circuit current or KA.

We have listed out several resources here on how to select, replace, and safely handle a tripped circuit breakers in this section.

Consumer Unit

The consumer units are also known as the distribution board box (DB box) are used for housing electrical protection equipment in residential buildings. Equipment such as the miniature circuit breakers (MCB) and residual current devices (RCD) such as the Residual Current Circuit Breakers (RCCB) are installed in the consumer unit. Other additional protection devices such as the lighting surge protection may also be installed.

Common types used in Singapore is the DIN rail mounted type.

Residual Current Circuit Breakers

The RCD (Residual Current Devices) are used for the protection of people and will instantly break an electric circuit to prevent serious harm from an ongoing electric shock. The residual-current circuit breaker (RCCB) is the most common device name in this group that is used together with an MCB to provide a complete protection. A combination of RCCB and MCB in a single device is known as an RCBO (residual-current circuit breaker with overcurrent protection)