SCP1000 / SCP2000 Shaft Speed Switches

SCP1000 / SCP2000 Shaft Speed Switches

Drummond is pleased to carry a variety of machine- and hazard-monitoring speed switches and sensors from Electro-Sensors, Inc.

Shaft speed switches sense the rotating shaft speed and compare it to one or more desired set points (e.g. over/under/zero). Shaft speed sensors detect magnets embedded in a shaft-mounted pulser wrap or disc. As the shaft rotates, the passing magnets are detected across an air-gap as pulses—with frequency proportional to the shaft’s RPM. When the pulse frequency (or shaft’s RPM) crosses to the alarm side of a trip-point threshold, a corresponding relay de-energizes, indicating the alarm. 


Features & Benefits:

  • Under speed, over speed, zero speed or reverse detection
  • Single or multiple setpoints
  • Rugged, reliable speed switches for hazardous areas
  • Output Options:
    • Relay Output
    • 4-20 mA Analog Output
    • DeviceNet
    • AS-Interface
  • Simple Installation and Calibration
  • Analog or Digital Electronics
  • Failsafe Operation
  • Integrated or Discrete Sensor
  • Start Delay
  • Explosion Proof or Enclosure Install
  • Input Power (DC, AC)
  • Water resistant and explosion-proof models available

Standard Speed Switch System Configurations:

3-Piece System

2-Piece System


  • Belt, Screw, Drag and Vibratory Conveyors
  • Crushers/Hammer mills
  • Rotary Airlocks
  • Fans/Blowers
  • Packaging Machines
  • Bucket Elevators
  • Pumps
  • Centrifuges
  • Turbines
  • Slide Gates and Valves

For more information about Electro-Sensors, see the Speed Switch Selector Guide.