Surge Protection Modules

What are Surge Protection Modules

LSP05 & LSP10 Thermally Protected Varistor Modules are designed for use in outdoor and commercial LED lighting fixtures for transient overvoltage protection. Constructed with Littelfuse thermally protected varistors, they provide robust surge current handling capability (Max Single Surge Current, 10kA@8/20us and 20kA@8/20us) and offer quick thermal response due to a thermal disconnect in close proximity to the MOV body.

These modules have UL 1449 3rd Edition Type 4 recognition and are compliant with IEC61643-11 Class II and EN61643-11 Type 2. They meet ANSI/IEEE C62.41.2 Location Category C High Exposure and US Dept of Energy MSSSLC LED Roadway Luminaries Model Spec, Elevated Electrical Immunity requirements. Both LSP05 and LSP10 are provided with parallel connections. The two parallel connection modules offer monitor indication wire options. The LSP10 is also available in series connection option.

What does it do

LSP Thermally Protected Varistor Modules are designed specifically for outdoor and commercial LED lighting applications. Their built-in thermal disconnect function provides additional protection from catastrophic failures and fire hazards, even under the extreme circumstances of MOV end of life or sustained overvoltage conditions. LSP05 and LSP10 modules are replaceable. The LSP10 series-connected version has a special indication function that turns the light off when it is activated.

Who are the target customers

  • Outdoor and commercial LED lighting fixture manufacturers
  • LED signage and traffic light manufacturers

Where this would typically be used

Outdoor and commercial LED lighting, including roadway lighting, traffic lighting, digital signage, service entrance lighting, parking garage/lot lighting, flood lighting, tunnel lighting, and street lighting.

Why Thermally Protected Varistor Module

The LSP Thermally Protected Varistor Module is replaceable and protects the lighting fixture/luminaire from damage due to transient overvoltage and overheating, reducing maintenance costs and extending luminaire lifetime. The indication wire can be connected to an indication circuit for light monitoring purposes.


  • Maximum Lightning Surge Current: 20,000A (LSP10); 10,000A (LSP05)
  • Thermally protected varistor technology
  • IP66 water-proof and dust-proof
  • Indication wire options
  • CE Compliance IEC61643-11 Class II/EN61643-11 Type 2
  • UL1449 Type 4 component assemblies recognition and compliant with IEC 61643-11 Class II and EN 61643-11 Type 2
  • Compact form factor (48x48x30mm) with mounting tabs


  • Optimized surge immunity solution to protect outdoor LED fixture investments
  • Internal varistors thermally protected to prevent failure due to end-of-life or continuous overvoltage faults
  • Flexible outdoor installation locations, inside or outside of luminaire, top or bottom at lighting pole, in transformer box or on distribution panel
  • Facilitates an indicating/monitoring circuit for SPD replacement
  • Enabling lighting fixture worldwide marketing
  • Small size makes it easier to mount inside luminaire; mounting tabs simplify installation and replacement