Mersen Brand Surge Protection Device 83020124 – STPT2-40K320V-2P


Mersen Brand Surge Protection Device 83020124 – STPT2-40K320V-2P

The Mersen STPT2-40K320V-2P Surge Protection Device (SPD) is a high-performance solution designed to safeguard your electrical systems from voltage surges. Certified to meet the rigorous standards of IEC 61643-11, EN 61643-11, and UL 1449 4th Edition, this SPD is ideal for various commercial, industrial, and residential applications.

Key Features & Benefits

  • Robust Surge Protection: The STP T2 40 series is engineered to handle maximum discharge currents of up to 40kA per phase (8/20μs), providing reliable protection against voltage surges.
  • Standards Compliance: Fully compliant with international standards EN/IEC 61643-11 and UL 1449 4th Ed., ensuring top-tier performance and safety.
  • Versatile Application: Suitable as a secondary protection stage in systems with upstream Type 1 devices or as the primary protection in settings without direct lightning exposure or external lightning protection systems.
  • Network Compatibility: Supports various network configurations, including TNS, TNC, TT, and IT networks.
  • Wide Voltage Range: Compatible with multiple voltage levels: 48V, 60V, 120/208V, 230/400V, 277/480V, 400/690V, and higher.
  • User-Friendly Design: DIN-rail mountable and plug-in format for easy installation and maintenance. The reversible chassis allows for flexible cable entry from either above or below.
  • Enhanced Safety: Features visual and remote end-of-life indicators to ensure timely maintenance and prevent operational downtime.
  • Error Prevention: Mechanically coded cartridges prevent incorrect replacements, enhancing safety and reliability.
  • Backup Fuse: Equipped with a 125 A gG backup fuse for additional protection.

Technical Specifications

  • Maximum Discharge Current (8/20μs): 40kA per phase
  • Nominal Discharge Current (8/20μs): 20kA per phase
  • Mounting: DIN-rail
  • Chassis: Reversible for flexible installation
  • Indicators: Visual and remote end-of-life
  • Backup Fuse: 125 A gG
  • UL File: E468946


The Mersen STPT2-40K320V-2P is suitable for a wide range of applications, ensuring comprehensive protection for diverse electrical environments:

  • Industry and Automation: Protects sensitive equipment and machinery from damaging voltage surges.
  • Commercial and Residential Installations: Ideal for safeguarding building electrical systems and consumer electronics.
  • Telecom & IT & Data Centers: Ensures continuous operation of critical communication and data processing equipment.
  • LED Outdoor Lighting: Prevents damage to LED lighting systems caused by power surges.
  • Water Treatment Facilities: Protects essential control and monitoring equipment.
  • Smart Grid & LV Metering: Ensures the reliability and longevity of smart grid components and low-voltage metering devices.
  • Renewable Energy: Suitable for photovoltaic and wind power installations, protecting inverters and other essential components from surges.


The Mersen STPT2-40K320V-2P Surge Protection Device is a versatile, reliable, and high-performance solution designed to meet the demanding requirements of modern electrical systems. Whether for industrial automation, commercial buildings, or renewable energy applications, this SPD offers robust protection against voltage surges, ensuring the safety and longevity of your equipment.