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Viper®-ST Recloser

Viper®-ST 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.

Features and Benefits

  • Reliable Performance – Viper®-ST reclosers utilize G&W Electric’s time-proven epoxy polymer system to fully encapsulate the vacuum interrupters. This system provides excellent insulation properties while providing fully shielded, void-free construction.

  • Ease of Operation – The Viper®-ST is compatible with the SEL-651R control along with a variety of other control options upon request.

  • Ease of Installation – The Viper®-ST is lightweight and compact. Site-ready designs provide all accessories preassembled prior to shipment, significantly reducing installation time.

  • Power Grid Automation Ready – The Viper®-ST is automation ready, simplifying conversion for any future automation requirements.

  • Dead-Line Operation – The unique design of the Viper®-ST magnetic actuator system provides for local and remote operation of the recloser on battery backup in the event that the AC source power is lost or interrupted.


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, A 800800800800800
8-hour Overload, A rms at 20°C960960960960960
60Hz Withstand, kV rms
- - - One minute (dry)5050606070
- - - 10 second (wet)4545505060
Radio Influence Voltage, microvolts @ 100 9.4kV9.4kV16.4kV16.4kV23kV
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
Ratings Chart for GNI Switches

Voltage Class, (kV)15kV25kV35 kV
Maximum design voltage (kV)15.5kV27kV38kV
BIL Impulse (kV)110kV125kV150kV
1 Min Withstand AC (kV)35kV60kV70kV
1 Min Withstand Production test rating AC (kV)34kV40kV50kV
15 Min Withstand DC (kV)53kV78kV103kV
Continuous and load break current (A)*630 amps630 amps630 amps
Momentary Current (kA) asym40kA asym40kA asym40kA asym
Fault-Close 3-times (kA) asym40kA asym40kA asym40kA asym
1 Sec Current (kA) sym25kA asym25kA asym25kA asym
Mechanical Operations200020002000
Symmetrical interrupting ratings (kA)**252525
*900A continuous available
**12.5kA and 20kA available