Viper®-ST Independent Pole Operated (IPO) Recloser

G&W Electric’s Viper®-ST independent pole operated (IPO) recloser combines the time proven reliability of electronically controlled, vacuum fault interrupters with the maintenance-free benefits of a solid dielectric insulated device. The IPO feature offers ultimate user flexibility by permitting three distinct mechanical operation modes, either 1-phase trip / 1-phase lockout, 1-phase trip / 3-phase lockout, or 3-phase trip / 3-phase lockout. The Viper -ST provides overcurrent protection for systems through 38kV maximum, up to 1000A continuous current, with 12.5kA symmetrical interrupting and 16kA symmetrical interrupting up to 27kV.  Vertical insulator “L” configurations and horizontal insulator “Z” configurations are available to increase installation flexibility.

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Features and Benefits

Configuration Details

  • Polemount Center Bracket
  • Polemount Alley-Arm Bracket
  • Polemount Complete Site-Ready Assembly
  • Polemount Cross-Arm Bracket
  • Polemount Cluster Bracket
  • Polemount Phase-over-Phase Bracket
  • Substation Mount Recloser
  • Padmount
Electrical Ratings Chart for Viper®-ST
Maximum Design Voltage, kV 15.52738
Impulse level (BIL), kV110110125125150
Continuous & load break current, A800800800800800
8-hour Overload, A rms at 20°C960960960960960
60Hz Withstand, kV rms
- - - One minute (dry)5050606070
- - - 10 second (wet)4545505060
Radio Influence Voltage, microvolts @ 1009.4kV9.4kV16.4kV16.4kV23kV
Interrupting Current, kA rms sym.12.51612.51612.5
Making Current, kA asym. rms2025202520
Making Current, kA asym. peak3242324232
Short Circuit Current, kA sym., 3 second12.51612.51612.5
Mechanical endurance operations10,00010,00010,00010,00010,000
Temperature range-60°C to +65°C-60°C to +65°C-60°C to +65°C-60°C to +65°C-60°C to +65°C
Continuous Current800A*800A*800A*800A*800A*
*Consult factory for higher continuous current up to 1000A


High Accuracy Sensors – Accusense Voltage Sensors

Controls – The Viper-ST works directly with a variety of popular controls.

G&W Electric VRC Control

G&W Electric introduces an economical and versatile control package for the Viper line of solid-dielectric reclosers. The Viper Recloser Control (VRC) provides a customizable control package tailored to fit the needs of any recloser application. The VRC has been designed with reliability and versatility in mind. With the VRC, G&W Electric can offer the Viper-ST packaged together with the SEL-351R3 Falcon, the SEL- 751A, or with virtually any other relay.

The VRC concept integrates the G&W Electric driving electronics and an Intelligent Electronic Device (relay) into a single enclosure. Accessories such as communication or security devices can be added to the package.


  • Reliability – Every Viper Recloser Control is system tested with its Viper Recloser to the IEEE C37.60 / IEC 62271-111 standards before leaving the factory
  • Lightweight and Economical – The VRC has been optimized to be a lightweight and economical control package
  • Temperature Range – The Viper Recloser Control has been tested to operate in temperatures from -40°C to +65°C


The SEL-651R Advanced Recloser Control offers exceptional protection and communications capabilities for Automatic Network Reconfiguration, three-phase and single-phase tripping, and other distribution automation needs. These capabilities help you maintain reliable service to as many customers as possible in the event of a fault.


  • Six voltage inputs support measurements on both sides of the recloser for advanced distribution automation and monitoring
  • ArcSenseTM technology(AST) detects and clears high-impedance faults for fire mitigation projects
  • Single-phase tripping minimizes outage times and improves reliability
  • Comprehensive communications protocols and interfaces ease integration into distribution automation systems
  • It supports IEEE 1547-2018 and fast islanding detection for distributed energy resource (DER) interconnections


The ABB RER620 recloser control has been tested to the required standards allowing it to be paired with either a 15kV or 27kV, 12kA Viper-ST and sold as a complete package. The enclosure is rated IPX5 and NEMA 3R. The ABB RER620 has an excellent feature set allowing it to be used in distribution overhead and automation applications. Some of the features include:


  • Accepts six LEA voltage sensing
  • Single or three phase tripping
  • Strong 61850 protocol platform
  • Internationally well-known
  • Extensive market experience and acceptance

Beckwith M-7679

Beckwith’s M-7679 R-PAC Next generation Protection, Automation, and Control System for Recloser, Switch, Sectionalizer and Distribution Automation Applications.


  • Over 30 Protection Elements for optimal protection of Power Distribution Systems
  • Compatible with Three Phase (Standard) and Independent Phase capable Reclosers, Switches and Sectionalizers (Optional)
  • Four (Standard) or Six (Optional) Low Energy Analog (LEA) or VT voltage inputs
  • Settings Wizard assists in creating files for the most common settings
  • Recloser Status Monitoring tool displays real time reclosing sequence and fault clearing time
  • Comprehensive I/O Matrix provides visual confirmation of enabled functions and selected outputs improving security
  • Embedded Cyber Security including:
    • Role Based Security
    • Complex passwords
    • Individual user accounts with activity log
    • IPSec (VPN) Tunnel
    • Compatible with Radius password management systems
  • PQ Monitoring


  • 3500 Sequence of Event Records
  • 100 Oscillographic Records (Up to 128 s/c & 480 Cycles each)
  • Over 2 years of data logging (at 5 min interval, adjustable)

GE Multilin R650 (IEC Configured)

The GE Multilin® R650 Recloser Control is a member of GE’s Multilin 650 family of field-proven protection and control devices, allowing customers to use the same platform both inside and outside the substation. This recloser controller delivers comprehensive performance in protection, monitoring, control, automatic network configuration and communications. With high speed, reliable performance this solution works to reduce customer outages and ensure fast recovery of medium voltage network sections for increased reliability of secondary distribution systems.


  • Protection and control- up to 32 programmable digital inputs; 16 digital outputs configurable PLC logic to IEC 61131-3
  • Advanced real-time monitoring, metering, and measurement
  • Enhanced user interface display with 16×40 graphics or standard 4×20 characters
  • Communication Protocols: DNP 3.0, IEC 61850 ed. 2, IEC 60870-5-101, 103 & 104, etc.
  • Optional fiber optic 100BaseFX Ethernet, single or redundant (PRP/HSR/RSTP)
  • Compact Case Size
  • Optional conformal coating for harsh environments
  • Extends the use of GE relays outside the substation for existing GE customers
  • Links with G&W Electric LaZer Distribution Automation software

Viper®-S and Viper®-ST Padmount


Viper®-ST Solid Dielectric, Triple Option Recloser Brochure – English


Low Fault Current Detection



Case Studies

Voltage Sensor Retrofit on Recloser


Automatic Source Transfer for Medical Plant


Renewable Intertie w Padmount Viper Reclosers


Non-Communicating Automatic Loop Restoration


Automatic Feeder Restoration in Residential Area


Solid Dielectric Padmount Recloser Alternative to Air Insulated


Three Phase Motor Fault Protection


Industrial Manufacturing Feeder Restoration

Application Guides

Viper®-ST Solid Dielectric Applications

White Papers

Fire Mitigation Strategies for Distribution

Unlock Resource

Viper®-ST Specification


Viper®-ST Padmount Specification

Technical Guides

Clearing Time for Viper®-ST & Viper®-SP