ASCO Model 420 Surge Protective Device

ASCO Model 420 Surge Protective Device | FrontView

The ASCO Model 420 is a compact Surge Protective Device that protects line to neutral and neutral to ground. The Model 420 uses thermally protected MOVs, is tested as a UL 1449 Type 1 device and is in a NEMA 4X enclosure, making this an ideal choice for both panel and equipment locations.


  • UL 1449 Fourth Edition Listed
  • 50kA per mode/phase rating
  • All UL required OCP and Safety Coordination included inside— Type 1 SPDs intended for Line or Load Side of Main Disconnect— Type 2 SPDs intended for Load Side of Main Disconnect
  • 20kA Inominal
  • 200kA SCCR


  • UL 96A Lightning Protection Master Label compliant (@20kA IN)Voltage Specific Design — Highly configurable
  • All MOV suppression elements monitored
  • NEMA 4X Indoor/Outdoor rated enclosure
  • 5 Year Warranty

Specification Documentation


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