DEHN 900439 Three-Phase Compact Surge Arrester TT/TNS (Type 2)

Electrical surges from lightning or switching operations can destroy sensitive three-phase equipment. The DEHN 900439 compact surge arrester protects TT and TNS systems by diverting transient overvoltages to ground, preventing costly downtime and damage.

Who is it for

Electricians and panel builders installing surge protection in commercial or industrial three-phase power distribution boards. Suitable for TT and TNS earthing systems where a compact DIN-rail mounted Type 2 arrester is required.

Main features

• Type 2 / Class II surge protection according to IEC 61643-11
• 3+1 circuit configuration for TT and TNS networks
• High discharge capacity: 20 kA nominal (8/20 µs) and 40 kA maximum
• Low voltage protection level ≤ 1.2 kV for effective equipment protection
• Visual status indication: green = OK, red = fault
• Compact thermoplastic housing, red, UL 94 V-0, for 35 mm DIN rail

Specifications

• Max. continuous operating voltage (Uc): 275 V AC
• Nominal discharge current (In): 20 kA (8/20 µs)
• Max. discharge current (Imax): 40 kA (8/20 µs)
• Voltage protection level (Up): ≤ 1.2 kV
• Response time: < 100 ns
• Short-circuit withstand capability: 50 kAeff with max. backup fuse
• Operating temperature range: -40 °C to +80 °C
• Protection degree: IP20
• Max. conductor cross-section: 35 mm² solid / 25 mm² stranded
• Standards: IEC 61643-11, EN 61643-11

Tips

Install as close as possible to the incoming supply of the distribution board. Ensure proper earthing and use recommended backup fuses for optimal short-circuit coordination.