OBO BETTERMANN Coordinated Lightning Controller MCD 50-B/3+1 Type 1 Surge Arrester 50kA 4-Pole 5096879

Lightning current arrester MCD 50-B/3+1 delivers robust Type 1 protection for low-voltage power systems, combining 50 kA (10/350 µs) total discharge capacity with a compact 4-module DIN-rail design. Its coordinated spark gap and varistor technology safely diverts high-energy lightning currents, protecting electrical installations from direct strike damage.

Advantages

High discharge capacity of 50 kA per phase ensures reliable protection against direct lightning strikes. The 3+1 circuit configuration suits TN-S and TT earthing systems, offering flexibility in installation. Low voltage protection level (<1.3 kV) safeguards sensitive electronics, while the fast response (<25 ns) minimizes let-through energy. Thermal disconnection and visual status indication enhance safety and maintenance. Flame-retardant thermoplastic housing and IP20 rating allow safe DIN-rail mounting in distribution boards.

Suitable for

• Main distribution boards in residential, commercial, and industrial buildings
• Power supply systems with TN-S or TT earthing arrangements
• Protection of sensitive equipment against direct lightning strikes and switching overvoltages
• Installations requiring compliance with IEC 61643-11 and EN 61643-11

Key specifications

• Arrester type: Lightning current arrester (Type 1)
• System configuration: 3+1 (L1, L2, L3, N-PE)
• Nominal voltage (Un): 230/400 V AC
• Max. continuous operating voltage (Uc): 280 V AC
• Lightning impulse current (Iimp) 10/350 µs: 50 kA total, 12.5 kA per pole
• Nominal discharge current (In) 8/20 µs: 50 kA total, 12.5 kA per pole
• Protection level (Up): < 1.3 kV
• Response time (tA): < 25 ns
• Max. backup fuse: 315 A gL/gG
• Short-circuit withstand capability (Isccr): 50 kA
• Follow current extinguishing capability (Ifi): 50 kA
• Thermal disconnection: Yes
• Remote signalling contact: No
• Mounting: DIN rail 35 mm
• Housing material: Thermoplastic, flame-retardant
• Degree of protection: IP20
• Operating temperature: -40 to +80 °C
• Standards: IEC 61643-11 / EN 61643-11

Recommendations

Install at the service entrance to protect the entire electrical installation. Ensure proper earthing and use appropriate backup fuses. For enhanced monitoring, consider a version with remote signalling contact if required. Regular inspection of the status indicator is advised.