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Select-SL3 Series

Select-SL3 Series

Selenium Enhanced Select® SL3™ was the first hybrid device that combined selenium cells with the Current Technology patented Integrated Suppression Module (ISM™). It features surge-rated copper busing, robust filtering, and superior remote communication capabilities. Selenium Enhanced Select SL3’s advanced technology delivers outstanding performance in all power quality surge events including temporary overvoltages.  


  • Hybrid design to deliver maximum performance and ensures a dramatically extended product life
  • Increased reliability 
  • Lower clamping voltages provides additional protection than typical metal oxide varistor (MOV) only systems
  • Easy access to real-time data via the display on the unit or remotely
  • Industry leader in surge suppression performance
  • Standard 20-year warranty


  • First successful hybrid device utilizing selenium cells
  • Surge-rated copper busing 
  • Robust filtering 
  • Advance remote communication capabilities such as Modbus or ethernet communication options                                  
  • Temporary Over Voltage + Transient Surge Protection

Standards, Certifications, Classifications

  • UL listed 1449 5th edition for Type 1 and Type 2 applications
  • cUL, and UL 1283
  • UL96A master label for lightning protection systems


  • Renewable energy
  • Motion
  • Food and beverage
  • Critical power facilities: Hospitals, Financial institutions, airports, data centers
  • Educational institutions
  • Wastewater treatment plants
  • Transportation
  • Oil, gas, and chemicals

Downloadable Resources

SL3 050 datasheet

SL3 080 datasheet 

SL3 100 datasheet

SL3 125 datasheet

SL3 150 datasheet

SL3 200 datasheet

SL3 250 datasheet

SL3 300 datasheet

SL3 Installation & Operation Manual

CT SL3 Guide Specification

Value Proposition

Selenium is the only technology that protects critical loads and downstream equipment from catastrophic overvoltages. MasterMind was the first monitoring system to provide real-time data on product performance, making our product much more reliable. Our system is capable of providing a time date stamps, magnitudes, and durations for most power quality events. This critical information can be accessed remotely through the addition of both modbus or ethernet communication options, or locally on the LCD display located on the SPD. End users have the ability to set alarm conditions by establishing the magnitude and duration required to trigger an alarm event. Our surge counter has the capability of categorizing surges into three industry recognizable categories, which exceeds the standard surge counter currently offered in the market. Our surge counter can register and record surge events in excess of 100A, eliminating false readings.