Disconnect Switches

 

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Product Center > Disconnect Switches

What Is A Disconnect Switch?


ROMAC specializes in low-voltage and medium-voltage disconnect switches.

Commercial-duty low-voltage disconnect switches include load break or non-load break; switchboard, panelboard or wall mount; fused or non-fused disconnects; and electrically closed, electrically opened, both or neither. Low-voltage disconnect switches interrupt or open an electrical circuit, isolating the downstream circuit for purposes of inspection and maintenance. Low-voltage disconnect switches are often used as main disconnecting devices in switchboards and even more frequently as feeder disconnects. Low-voltage disconnect switches can serve as enclosures for overcurrent protection when they contain fuses. Disconnect switches can also be a part of a ground fault protection scheme when equipped with a shunt trip or a complete ground fault interrupter system that includes a shunt-trippable disconnect switch, ground fault monitor, sensor and relay.

Like low-voltage disconnect switches, medium-voltage disconnect switches perform a number of functions. The term "disconnect" refers to the act of interrupting or causing an opening in an electrical circuit. In addition to turning off whatever load is consuming this electricity, disconnecting allows for the isolation of the downstream circuit for purposes of inspection and maintenance.

Disconnect switches often serve as enclosures for overcurrent protection when they contain fuses. Some can also be a part of a larger protection scheme when equipped with a shunt trip that can be signaled by relays elsewhere in the network.


Major Components of Disconnect Switches

Low-voltage disconnect switch parts and subassemblies include but are not limited to:
  • Frame or enclosure
  • Insulating system
  • Current carrying components
  • Contact systems
  • Arc extinguishers
  • Operating mechanism
  • Interlocks
  • Auxiliary or pilot devices

Medium-voltage disconnect switch parts and subassemblies include but are not limited to:
  • Enclosure
  • Interlocks
  • Interphase barriers
  • Arc extinguishers
  • Arcing contacts or blades
  • Live parts such as fuse holders
  • Operating mechanism
  • Spring charging motor
  • Push rods
  • Vacuum bottles
  • Shunt trip assembly
  • Thermostat
  • Space heater
  • Door closures
  • Viewing window
  • Limit switches
  • Control circuit
  • Voltage transformer
  • Current transformer
  • Control power transformer
  • Protective relays
  • Insulating materials or devices
  • Bus
  • Bus barriers
  • Cable terminations


ROMAC's Reconditioned Disconnect Switch Inventory

Reconditioning is the process of returning electrical equipment to safe and reliable operating condition based upon the design of the original manufacturer at the time of manufacturing. ROMAC regularly carries inventory from all the major disconnect switch manufacturers, including: GE, Cutler-Hammer, SquareD, Siemens, and Westinghouse. ROMAC follows PEARL industry standards to recondition a disconnect switch, including procedures to test, inspect, disassemble and recondition – including clean, polish, deburr, paint, lubricate, adjust or torque individual parts of the disconnect switch. After reconditioning, subassemblies can be reinstalled in the now cleaned and painted enclosure or frame, including the addition of upgrades or options to improve the apparatus’s performance. Assembly of the reconditioned components and subassemblies is followed by final inspection and testing. As with all testing, inspection and reconditioning operations, final inspection and test results are recorded onto the valuation and test forms included with the standard.