MagneX Interrupters

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MagneX™ Interupters

A compact way to protect distribution transformers from overload and faults, and provide a reliable method for switching transformers "on" or "off".


The MagneX™ Interrupter is an overcurrent protective device that protects distribution transformers from damaging overloads and secondary faults, and is also used for switching the transformer “on” or “off.” As a transformer protective device, the MagneX Interrupter combines safety and efficiency with economic operation.

It is an integral assembly, which does not use a troublesome linkage or require calibration, making installation and operation fast and trouble free. The housing is made of an ultraviolet stabilized, high-strength, glass-filled thermoplastic material. The operating shaft is sealed against leakage with a double-Viton® O-ring seal.

  • The single-phase MagneX Interrupter combines the functionality of one Bay-O-Net fuse and one single-phase on/off Loadbreak switch in one protective device, and is ideal for single-phase pad- and pole-mounted transformer applications.
  • The three-phase MagneX Interrupter combines the functionality of three Bay-O-Net fuses and one three-phase on/off loadbreak switch into one protective device, and is ideal for three-phase pad-mounted transformer applications.
  • The two-phase MagneX Interrupter is designed for single-phase applications where disconnecting both primary coil leads is desirable. This feature is ideal for two-bushing transformers, where a fault on either leg of the transformer may cause activation of the protective device.
  • Secondary faults and overloads will trip the MagneX Interrupter “open.” However, the device can be reset once the condition is corrected. The MagneX Interrupter, in coordination with either an isolation link or current-limiting fuse, also clears primary faults.
  • The MagneX Interrupter can also be used as a primary switch to disconnect the transformer windings — not just the load. This eliminates core (no-load) losses on transformers not in service. Residual voltage problems associated with secondary breakers during banking of transformers are also eliminated.