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Switches & Disconnects - Safety Switches
Spec Setter* Mill Duty

Spec Setter* Mill Duty

Mill duty safety switches are designed specifically for the rugged conditions found in steel mills, cement foundries and other process-related environments.


Dedicated mill duty switches are available for 400 and 600 amps, 600 Vac, 600 Vdc maximum, fusible and non-fusible units, and in NEMA Type 4/4X (water and dust-tight, corrosion resistant) and Type 12 (drip and dust-tight) enclosures. Standard Heavy Duty switches can be used for mill duty applications for 30-200 amps (use NEMA Type 5/12 indoor enclosure).  Horsepower ratings are to UL Listed maximums; published I2t ratings are available. Short circuit ratings are UL Listed to 200,000 rms symmetrical amps when Class J or R fuses are installed.

Our mill duty safety switches are UL Listed and CSA certified (UL98 Enclosed Switches/CSA-C22.2 No. 4-04), meet Federal Specification WS-865C for heavy duty switches and meet NEMA Enclosed Safety Switch Standard KS1-2001.

Features and Benefits

  • Best suited for rugged environmental conditions such as mills and foundries.
  • Bright red "donut" handle molded from rugged SE1 Noryl thermoplastic is easy to see, easy to grip and ideal for hook stick operation. It accepts three padlocks in OFF position.
  • Manual interlock defeat lever permits contact inspection when switch is OFF.
  • Standard NEMA 12 enclosure protects interior from dust, lint, fibers, coolants, metal filings and other non-corrosive contaminants. Stainless steel NEMA 4/4X enclosure additionally shields interior from hose directed water, splashing and falling liquids. Interlocks on all enclosure covers assure gasket compression before switch can be turned ON.
  • Efficient space-saving enclosures, three-point mounting, unobstructed side wiring gutter, easily removable cover and interior.
  • Spring-reinforced fuse clips assure reliable contact for cool operation. Suitable for Class H, K, J or R fuses.
  • Equipment ground lugs provided. Lugs approved for both copper and aluminum wire; 60/75 degree C rated tang lugs are field convertible to compression (crimp) connectors.
  • Highly visible ON/OFF label takes the guesswork out of safety and gives a clean, modern appearance


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