G&W Viper-S and Viper-ST three phase reclosers now have the option of incorporating six integral capacitive voltage sensors to allow for voltage measurement on both the line and load sides of the device without the need for costly and heavy potential transformers. This makes G&W Viper reclosers with Six Voltage Sensors (6VS) ideal for distribution automation applications and loop or network reconfiguration schemes.

Applications

• Open Bus-Tie Breaker - Either substation mounted or overhead, where the presence or loss of voltage is used to trigger the tie breaker to close and restore power.
• FDIR - Fault Detection Isolation and Restoration where communications are used between recloser controls to operate and restore power. In the event there is a loss of communication and six voltages are being monitored, the recloser control can even be programmed to deploy FDIR without the need for communications, providing the highest level of reliability.
• Automatic Transfer - To monitor two independent source voltages. Six Voltage Sensing permits the control to sense loss of voltage on the primary source and verify a stable voltage reading on the secondary source which asssures a proper, safe transfer even if communications is lost.
• Distributed Generation - Where the electric grid is synchronized with backup generators. Having six voltage sensors allows the recloser control to monitor phase angle and voltage amplitude of each phase to close the recloser safely when connecting the generator to the grid.

Operation

Six Voltage Sensing is accomplished through capacitive voltage dividers embedded in the epoxy insulation of each phase of the recloser. The sensors have a Low Energy Analog (LEA) output.  The capacitive voltage sensors are isolated from the grid and are able to read phase angle and voltage amplitude with a relatively high accuracy. The sensors do not provide power to the recloser control. External sources such as PTs can be supplied to power the relay.

Accuracy

The voltage sensors have been tested in a third party laboratory. Voltage sensing amplitude accuracy is +/-2% when tested as a system from -10°C (14°F) to +45°C (113°F). The VS accuracy is +/-4% at -40°C (-40°F) to +65°C (149°F). The phase angle accuracy is +/-1° throughout the full temperature range. Current monitoring is provided through integral multi-ratio current transformers encapsulated within the module of each phase. Ratios available are 1000:1 or 500:1. Inputs to the control are field changeable. CT accuracy is +/- 1%.

Features

• Operator Safety - Vacuum interrupters are sealed within solid dielectric insulation providing fully shielded modules. The module housing, being at ground potential, provides additional safety. A hookstick operable, manual trip and lockout handle prohibits operation either from the control or remotely. A mechanical blocking device further assures against accidental close through the handle. An open and closed contact indicator verifies contact position. Contact status and lock-out condition can also be verified at the control.
• Reliability - Having both the current and voltage sensors embedded into the epoxy module protects them from environmental damage or contamination and makes for a cleaner, and less cluttered installation. Other manufacturers must use expensive, external add-on sensors or potential transformers to accomplish the same functionality which can significantly increase installation costs and result in a much more congested appearance.
• Compact, Lightweight Construction - Built-in sensors eliminate the need for heavy, add-on potential transformers or other sensors significantly reducing the overall weight of the installation. The Viper-ST has one single control cable that brings all voltage, current, breaker status and trip/close information into the control. The Viper-S comes with a 19-pin interface and an 8-pin cable for the voltage sensors.

• Ratings
• 6VS LEA Features Comparison Chart
• Components Viper-S with 6VS
• Components Viper-ST with 6VS
• Controls