RCDs & RCCBs

For the Trade

Start with the space you’ve got and how the circuit will be used, because that usually decides the unit before you get into finishes or extras. On a tight board, a compact option saves grief. On a busier layout, you want the arrangement that leaves room to work without crowding the rest of the gear. For mixed-load circuits, a type a rcd is usually the safer call. A type ac rcd still suits simpler jobs where the load is straightforward. The call-back jobs tend to come from specs chosen for convenience, not the actual use.

Types of RCDs & RCCBs

RCDs usually come down to what the circuit is feeding and how much discrimination you need with the rest of the board. A residual current circuit breaker suits jobs where you want the protection built into the device. Standalone residual current devices work when the protection is handled elsewhere.

Type A RCDs are the better fit for mixed electronic loads because they cope with more than the plain AC pattern. A type AC RCD still has a place on simpler circuits if that is what the spec calls for. Back at the wider Power Distribution & Circuit Protection setup, the choice is between one device doing the job or a separate arrangement with more flexibility.

Selection Factors for RCDs & RCCBs

The first check is what the circuit is feeding and how much room you’ve got in the board. On mixed loads or anything with electronics, a type A RCD is usually the safer pick. Type AC RCDs still have a place on simpler circuits, but they drop out once the load gets less straightforward.

If you need the protection built into the device, an RCCB will not do the same job as a combined unit. Check what the board needs before you order. For the bits around the board, Consumer Unit Accessories are often bought at the same time. If the job sits in a larger supply arrangement, 3 Phase Distribution is the next place to look.

Finish the Room

Once you’ve picked the RCDs, the next call is usually the board and the bits around it. A tidy consumer unit layout saves grief later. A cramped board makes testing awkward, and future swaps take longer than they should.

If the job needs a fuller distribution setup, move across to 3 Phase Distribution rather than trying to force it through a standard arrangement. For the smaller details that finish the board properly, Consumer Unit Accessories covers the blanks, covers and fixings that keep the install neat.