Circuit-Switchers and Circuit¬ Isolator II Disconnects

Circuit-Switcher: The Multipurpose Transmission-Voltage Switching and Protection Device

S&C Circuit-Switchers are ideal for:

• Transformer switching and protection.
• Capacitor-bank switching and protection.
• Reactor switching and protection.
• Line and cable switching.

They’re suitable for frequent operation over a long period of time with minimal maintenance. They can close, carry, and interrupt fault currents as well as load currents and are available in voltage ratings from 34.5 kV through 230 kV, with continuous-current ratings of 1200, 1600, and 2000 amperes.

S&C Circuit-Switchers provide high-speed circuit interruption of overloads and secondary faults, and protect transmission circuits from all types of transformer faults. Circuit-Switcher economics make it practical to provide protection at each load-tap transformer, without resorting to remote tripping arrangements such as transfer-trip relaying, or automatic-grounding-switch or sacrificial switching schemes.

S&C Circuit-Switchers can switch and protect all practical sizes of load-tap transformers, and single and back-to-back shunt capacitor banks, up through the following:

S&C Circuit-Switchers are offered in several versions:
Mark V Circuit-Switchers employ in-series circuit-breaking interrupters and a high-speed circuit-making and isolating disconnect. They can be custom-tailored to fit any structure, phase spacing, or bus height. And they can be furnished with pre-insertion inductors for unsurpassed capacitor switching.

Mark VI Circuit-Switchers combine Trans-Rupter II’s innovative interrupter technology (see pages 92 and 93) with Mark V’s high-speed circuit-making and isolating disconnect. Mark VI Circuit-Switchers can also be furnished with pre-insertion inductors . . . the industry standard for reducing inrush current and transient overvoltages when switching capacitor banks

Series 2000 Circuit-Switchers feature interrupters designed to close the circuit, interrupt the circuit, and maintain rated dielectric strength when open. They’re available in mounting configurations suiting the broad spectrum of substation layouts and profiles, with or without an integral power-operated disconnect.

All Circuit-Switcher interrupters use no-maintenance single-pressure SF6 puffer technology for restrike-free, non-current-chopping, minimum-voltage surge performance. They’re field-proven through 40 years of superior service. Isolating disconnect blades feature current-carrying contacts with built-in wiping action, assuring a clean, low-resistance path. Operators are designed to assure the full inherent mechanical and electrical performance characteristics of Circuit-Switchers.

Circuit-Isolator II Disconnect
S&C’s Circuit-Isolator II Disconnects provide three-pole, group-operated, visible-air-gap isolation in distribution substations. They can interrupt low-level charging currents associated with substation buswork and circuit breaker bushings, and are ideally suited for use with S&C Trans-Rupter II® Transformer Protector and Type SMD® Power Fuses.

Circuit-Isolator II Disconnects are available in voltage ratings from 69 kV through 138 kV, with continuous-current ratings of 1200, 1600, and 2000 amperes. Side-break, vertical-break, center-break, and double-break styles can be furnished, to suit almost any substation layout.