Why Choose the Mersen 83120134 Surge Protection Device?

The Mersen 83120134 STPT12-12K440V-3P is a robust Type 1+2 Surge Protection Device (SPD) designed to protect low voltage electrical installations against transient overvoltages caused by lightning activity and electrical switching events. As part of the Mersen Surge-Trap® Pluggable STPT12 Series, it provides reliable first-stage surge protection for industrial, commercial and infrastructure power distribution systems.

This pluggable SPD combines Class I and Class II surge protection in a compact DIN rail mounted format. Its replaceable cartridge design and clear status indication help simplify inspection and maintenance, making it suitable for incoming supply panels and installations exposed to atmospheric surges.

With a 12.5 kA lightning impulse current rating, 400/690 V nominal operating voltage and 440 V maximum continuous operating voltage, the Mersen 83120134 is ideal for protecting three-phase IT and TNC distribution systems, switchboards, control panels and sensitive electrical equipment from damaging voltage surges.

Key Advantages

• Combined Type 1+2 surge protection for low voltage installations.
• 12.5 kA lightning impulse current (Iimp) for robust surge handling.
• 440 V maximum continuous operating voltage for 400/690 V systems.
• Pluggable cartridge design supports fast replacement and maintenance.
• Compact 3-pole, 3-module DIN rail format.
• Suitable for main distribution boards, incoming panels and industrial power systems.

Key Features

• Mersen Surge-Trap® Pluggable STPT12 Series.
• Type 1+2 / Class I+II surge protection device.
• 12.5 kA Iimp (10/350 μs).
• 50 kA maximum discharge current (Imax 8/20 μs).
• 20 kA nominal discharge current (In 8/20 μs).
• 400/690 V nominal operating voltage.
• 440 V maximum continuous operating voltage.
• 3-pole configuration for 3+0 IT / TNC systems.
• DIN rail mounted IP20 construction.

Technical Specifications

• Manufacturer: Mersen
• Series: Surge-Trap® Pluggable STPT12
• Model: STPT12-12K440V-3P
• SKU: 83120134
• Product type: Type 1+2 Surge Protection Device
• IEC classification: Class I+II
• Lightning impulse current (Iimp): 12.5 kA (10/350 μs)
• Maximum discharge current (Imax): 50 kA (8/20 μs)
• Nominal discharge current (In): 20 kA (8/20 μs)
• Nominal operating voltage (Un): 400/690 V AC
• Maximum continuous operating voltage (Uc): 440 V
• System configuration: 3+0 IT / TNC
• Network type: 3 phase
• Protection mode: L-PE(N)
• Number of poles: 3
• Number of modules: 3
• Mounting type: 35 mm DIN rail
• Protection rating: IP20
• Format: Pluggable
• Dimensions (W × H × D): approx. 63 × 90 × 117 mm
• Weight: approx. 0.564 kg

Reliable Protection Against Electrical Surges

Surge protection devices help protect electrical systems by safely limiting transient overvoltages before they reach connected equipment. This reduces the risk of damage to switchgear, control systems, drives, PLCs, instrumentation, power supplies and other sensitive electrical components.

The Mersen STPT12 range is designed for use as the first level of protection in main distribution boards and incoming supply panels. Its Type 1+2 classification makes it suitable for installations exposed to atmospheric surges and applications requiring coordinated protection against lightning currents and voltage spikes.

Typical Applications

• Main low voltage distribution boards.
• Incoming power supply panels.
• Three-phase IT and TNC electrical systems.
• Industrial automation and control panels.
• Commercial building electrical installations.
• Switchboards, panel building and infrastructure systems.

Trusted for Critical Power Protection

Mersen Surge-Trap® surge protection devices are trusted by electrical engineers, panel builders and industrial facilities worldwide for dependable protection of power distribution systems and sensitive connected equipment.