What DEHN Provides

DEHN is a leading manufacturer of surge protective devices (SPDs), lightning protection and earthing systems for power, data and signal lines in industrial and building installations.

Selecting a Surge Protector

• Protected line: Power (TN-S, TT, TNC), data/signal (4–20 mA, Ethernet, fieldbus) or coaxial — each needs a type-matched SPD.
• Voltage class and Type: Type 1 (lightning, at service entrance), Type 2 (distribution boards), Type 3 (point of use). Often combined Type 1+2.
• Surge current rating: Match Iimp/In to the exposure and the upstream protector.
• Replaceable modules: Prefer pluggable modules with a fault indicator for fast maintenance.

Coordination and Wiring

1. Place Type 1/2 at the main incomer and Type 2/3 downstream, respecting the energy-coordination distance.
2. Use dedicated, short, straight bonding conductors to the earthing busbar — length kills protection.
3. Protect both line and neutral (and data pairs) so surges have no path around the device.

Maintenance

SPDs degrade silently after large events. Check the status indicator at inspections and replace modules that show fault. A properly coordinated scheme protects sensitive drives, PLCs and instrumentation from costly downtime.