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OVRHMSU (Modular Series-Connected Unit) Surge Protective Device is engineered to protect hard-wired installations within or adjacent to electrical loads such as outdoor lighting, robotics, process automation systems, motors, HVAC systems, pumps, heaters, programmable logic controllers, and other point-of-use applications. Compact and powerful, the OVRHMSU employs MOVs in parallel arrays placed at the input and output terminals to guard these and other individual components against damaging electrical transients, high-frequency noise, and high energy disturbances. OVRHMSU provides 50 kA of surge protection for loads up to 24 A.

Product Benefits

  • Series-connected design
  • Compact footprint saves space
  • Easy installation saves time and labor cost
  • High-frequency noise filtering helps extend equipment’s life span

Product Features

  • Recognized to UL 1449 4th Edition as a Type 2 compliant assembly
  • Parallel MOV arrays deliver protection from voltage spikes
  • Rugged, and durable polycarbonate enclosure
  • Easy-to-read LED status indication
  • Component level fusing

Technical Specifications

  • Maximum Surge Current Rating 50kA Per Mode
  • Voltage (Single-Phase Applications) 120, 220 or 277
  • Voltage (3-Wire + Ground Applications) 220/380 or 277/480
  • Voltage (Split-Phase Applications) 120/240


  • Outdoor lighting
  • Robotics
  • Process automation systems
  • Motors
  • HVAC systems
  • Pumps
  • Heaters
  • Programmable logic controllers
  • Other point-of-use applications

Certifications & Standards

  • Listed by ETL to UL 1449 4th Edition, Type 4 for Type 2 SPD applications,  cUL and UL 1283
  • Compliant to IEEE C62.41.1-2002, C62.41.2-2002, and C62.45-2002
  • NFPA 70 [NEC], Article 285
  • RoHS Compliant
  • CE, IEC 61643-11-2011
  • EMC Directive 2004/108/EC
  • Low Voltage Directive 2006/95/EC

Downloadable Resources

OVRHMSU Surge Protective Devices Datasheet

OVRHMSU Surge Protective Device Manual

Surge Protective Devices UL US Catalog