BG CUSPDT21EN Type 2 40kA Single-Module Surge Protection Device for TN-S, PME and TT Systems

The BG CUSPDT21EN-01 Type 2 surge protection device provides reliable protection for domestic and light-commercial electrical installations against transient overvoltages caused by lightning activity and electrical switching events. Installed within a compatible consumer unit, this 40kA single-phase SPD diverts damaging voltage surges safely to earth, helping protect connected circuits, appliances and sensitive electronic equipment.

Designed for TN-S, TN-C-S/PME and TT earthing systems, the CUSPDT21EN-01 is suitable for a wide range of UK electrical installations. Its compact single-module DIN rail design occupies minimal space inside the consumer unit, helping electricians retain more usable capacity for circuit-protection devices. The unit mounts directly onto the busbar and does not require a separate backup MCB.

The BG Type 2 SPD offers a maximum discharge current of 40kA, a nominal discharge current of 20kA and a rapid response time of less than 25 nanoseconds. It has a maximum continuous operating voltage of 275V and a voltage protection level below 1.5kV, providing fast protection when potentially damaging transient voltage spikes occur.

A clear visual status indicator makes routine inspection straightforward: green indicates that the device is operational, while red shows that the SPD requires replacement. The device also incorporates an internal current-limiting safety circuit designed to create a failsafe open circuit if exposed to excessive short-circuit current.

Compliant with BS EN 61643-11, IEC EN 61643-11 and BS EN 62305, the BG CUSPDT21EN-01 is also designed to meet current BS 7671 Amendment 4 requirements. It is an ideal choice for electricians searching for a Type 2 SPD, 40kA surge protection device, single-module consumer unit SPD, DIN rail surge arrester or BG consumer unit surge protector. BG circuit-protection products are covered by a 10-year manufacturer’s warranty.