13A RCD Fused Spur Unit Type A 30mA - White Rounded Edge

The Knightsbridge CU6RCD is a 13A RCD fused spur unit with Type A 30mA residual current protection built into a white rounded-edge plate. The Type A RCD protects against both standard AC residual currents and pulsating DC currents up to 6mA, which makes it suitable for circuits supplying IT equipment, variable-speed drives and modern appliances with switch-mode power supplies that generate DC leakage.

Designed for fixed appliance circuits where a fused spur is required by regulation or where it offers practical benefit over a standard socket, the unit combines a 13A fuse carrier with the RCD protection in a single plate. The RCD trips at 30mA within 40ms when residual current is detected, providing protection against electric shock in circuits where earth fault current might not be high enough to blow a fuse or trip an MCB. The double-pole contact break isolates both live and neutral lines when the RCD trips or when manually switched off.

The white thermoset resin plate measures 86mm square with a 12mm projection from the wall once fitted, and requires a minimum 35mm back box depth. The rounded-edge design softens the profile compared to square-edge plates and suits contemporary residential and light commercial installations. The captive terminals prevent loose screws falling into the back box during wiring, and the earth terminal is provided as standard. An LED indicator shows red when the RCD is active and green when switched off, with a yellow test button allowing monthly function checks as recommended by BS 7671.

Product Specification Sheet

What's the difference between Type A and Type AC RCDs?

Type A RCDs protect against both standard AC residual currents and pulsating DC currents up to 6mA, which are generated by modern electronic equipment including computers, washing machines with inverter motors, and LED dimmers. Type AC RCDs only detect AC residual currents, so Type A is required by current wiring regulations for circuits supplying such equipment.

What back box depth is required?

A minimum 35mm back box depth is needed for safe installation. The plate adds 12mm of projection from the wall surface once fitted.

How often should the test button be pressed?

BS 7671 (18th Edition) recommends testing RCDs at least quarterly. Press the yellow test button — the unit should trip and the indicator should change from red to green. If the RCD does not trip, it should be replaced immediately.

Can this replace a standard fused spur?

Yes, provided there is sufficient back box depth and the additional RCD protection is appropriate for the circuit. This unit is particularly useful for circuits supplying bathroom equipment, outdoor sockets via an indoor spur, or IT equipment where additional shock protection is beneficial.