Milli-Speed Switch

Underspeed Monitor


The Milli-Speed Switch with 4 - 20 mA output is designed to detect belt slip, belt underspeed, stop motion, low speed or zero speed on bucket elevators, conveyors, airlocks, mixers, fans, grinders and many other rotating machines.  Totally sealed and simple to calibrate, the Milli-Speed works in the harshest of conditions.

An inductive sensing device located in the nose of the Milli-Speed enclosure will detect a metal target.  This target can be an existing bolt head or device attached to a shaft, such as 4B’s Whirligig® sensor mount.  During installation, the Milli-Speed is set to the normal running RPM by simple magnetic calibration.

4B  Milli speed switch
Product Features: 
  • 4 - 20 mA Output
  • Simple Magnetic Calibration
  • Loop Powered (2 Wire)
  • Totally Sealed Construction: Submersible
  • Built In Conduit Adaptor (1/2” NPT)
  • Easy Installation with Whirligig® Sensor Mount
  • SpeedMaster™ Compatible for Accurate Testing
Speed Switches
Electronics Application: 
Bucket Elevator, Belt Conveyor
Speed Switch Demonstration Video