Circuit Breakers & ProtectionDistribution Boards & Enclosures
Breakers protect cables from overload; RCCBs protect people from earth leakage. Here is how to tell them apart.
Ask us a questionA miniature circuit breaker (MCB) switches off when a circuit draws more current than its rating, or when there is a short circuit. Lighting circuits commonly use a lower rating than socket circuits; your electrician matches the rating to the cable size. MCBs are also sold by breaking capacity (for example 6kA or 10kA) and trip curve (B, C or D).
An MCB trips on overload and short circuit. It protects the cable.
A residual current circuit breaker (RCCB) compares the current going out and coming back. If some leaks to earth, for example through a faulty appliance or a person, it trips within a fraction of a second. 30 mA is the usual sensitivity for protecting people; higher values such as 100 mA are used for wider installation protection. Your electrician will choose what the installation needs.
An RCCB trips when current leaks to earth. It protects people from electric shock.
An RCBO does both jobs for one circuit, so a fault on that circuit does not switch off the whole house. Surge protective devices (SPD) help protect equipment from voltage spikes, for example from lightning nearby.
An RCBO combines both in one module for a single circuit.
Send us the brand, amp rating, number of poles, breaking capacity and, for RCCBs, the sensitivity. A photo of the existing distribution board helps us match the module width and series. Distribution board work must be carried out by a qualified electrician.
Ratings: amps (e.g. 6A, 16A, 32A), poles (1P, 2P, 4P) and, for RCCBs, sensitivity (e.g. 30 mA, 100 mA).
This guide is general advice. Fixed wiring and distribution board work should be done by a qualified electrician.
D-One Electrical is in Taman Bukit Indah, Iskandar Puteri, minutes from the Second Link. Bring the model number or a photo and we'll find it.
Prices change with stock and quantity, so we quote on request.
