The 4B Milli-Speed Switch has a 4-20 mA output that is designed to detect a variety of conditions including: belt underspeed, stop motion, belt slip, low speed or zero speed. The Milli-Speed Switch can be used on bucket elevators, conveyors, mixers, fans, grinders and many other rotating machines. The Milli-Speed Switch is totally sealed to allow for monitoring in harsh 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.
The Milli-Speed is designed to operate over a speed range of 20 to 3,600 PPM (4-20 mA output). During installation, the Milli-Speed is set to the normal running RPM by simple magnetic calibration (17 mA output). A 20 mA output signal occurs when speed is 23% higher than the calibrated normal running RPM. A 4 mA output signal is produced when speed falls between 0 to 10% of the calibrated speed.