Hager SPB420 Type 2 Surge Arrester 3P+N 275V AC 40kA DIN Rail

The Hager SPB420 is a Type 2 surge protective device engineered for TN-S and TT earthing systems, providing reliable protection against transient overvoltages in low-voltage installations. Its 3P+N configuration and 40 kA maximum discharge current set it apart from basic single-pole arresters, making it suitable for main distribution boards where robust surge diversion is required.

Highlights

• Type 2 SPD per EN 61643-11 for TN-S and TT systems
• 3P+N (4-pole) design with 4-module DIN rail mounting
• Nominal discharge current 20 kA, maximum 40 kA (8/20 µs)
• Voltage protection level below 1.5 kV for sensitive loads
• Visual status indicator (green/red) for quick health checks

In daily use

The SPB420 installs on a standard DIN rail and connects with flexible conductors up to 35 mm² or rigid up to 50 mm². Its metal oxide varistor technology responds instantly to surges, clamping voltage to safe levels. The integrated indicator shows green when operational and red when replacement is needed, simplifying maintenance in commercial and residential panels.

Full specifications

• Type: Type 2 SPD
• Earthing systems: TN-S, TT
• Poles: 3P+N
• Nominal discharge current (In): 20 kA
• Maximum discharge current (Imax): 40 kA
• Voltage protection level (Up): < 1.5 kV
• Maximum continuous operating voltage (Uc): 275 V AC
• Technology: Metal oxide varistor (MOV)
• Mounting: DIN rail, 4 modules (72 mm)
• Status indication: Visual (green/red)
• Max. upstream overcurrent protection: 315 A gG
• Short-circuit current rating (Isccr): 50 kA
• Connection cross-section flexible: 1.5–35 mm²
• Connection cross-section rigid: 1.5–50 mm²
• Degree of protection: IP20
• Operating temperature: -25 to +60 °C
• Standards: EN 61643-11

Final note

For coordinated surge protection, pair the SPB420 with upstream Type 1 devices and downstream Type 3 units as part of a complete protection concept.