HE300-15 (AC Surge Protector)

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The HE300-15 surge arrestor is the first line of protection for the electronic equipment in a traffic controller cabinet.

This unit is a two-stage arrestor which can be used as a stand-alone device or in conjunction with an external line filter if required. Because the primary and secondary stages are electrically separated (line side), the addition of an external filter (HESCO/RLS model LF35, LF50 or LF60) is simple and quick.

The primary stage is designed to dissipate high-energy surges on the AC powerline of 46KA (8x20uS) while clamping at a nominal 480 volts. The primary stage provides protection from line to neutral, line to ground and neutral to ground. This feature becomes quite important at site locations where neutral must be kept isolated from earth ground inside the controller cabinet.

In addition to the primary stage’s capability to sustain multiple surges of 46KA (8x20uS), the secondary stage is designed to sustain surges in excess of 20KA (8x20uS) at a clamp voltage of 340 volts.

The HE300-15 surge arrestor is one of the most powerful hybrid surge arrestors available today.

Download Specifications Sheet (PDF}


Peak Surge Current (8x20us)
First Stage 46KA
Second Stage 20KA
Overall Occurrences:
46KA (8x20uS) 10 Times
33KA (8x20uS) 20 Times
20KA (8x20uS) 40 Times
Clamp Voltage
46KA (8x20uS) 478 volts*(337 VAC)
20KA (8x20uS) 340 volts*(240 VAC)
Response Time <5 Ns
The voltage never exceeds 340 VDC during a surge of 20KA (8x20us) or less.
Series Inductance 235uH Total
Continuous Service Current
120 VAC, 50-60 Hz
15 Amps Max
Dimensions (in) 2.875 W x 5.30 L x 1.70 H
Temperature Range -40°C to +85°C
Weight 1.6 lb
*Unit was tested with neutral strapped to the ground terminal


  • Multi-Stage Surge Arrestor
  • Protects Against Lightning And Other Power Surges
  • Clamps Harmful Surges Quickly
  • Completely Weatherproof
  • Immediately Self-Restores After Each Surge
  • Filter Component Meets MIL-STD-220A Insertion Loss Specifications