Providing Solutions in centrifugal
Speed Switching for Over 65 years
Motor Switch Selector
Unit of Measure


Shipping Weight

N/A 4 Pound1.8 Kilogram


N/A Flange




N/A 0.1 to 500.0


N/A 22 to 30 VDC


N/A Single

Input Power - Options

N/A 120 VAC and 240 VAC ± 10 % 50/60 Hz
12 to 15 VDC, 22-30 VDC, and 100 to 130 VDC

Output Power

N/A 10.0 amps contact rating @ 250 VAC/30 VDC

Speed Ranges

N/A 0.1 to 500.0 (1/60 turn response)

Prestart Delay

N/A 20 seconds (0.1 to 500 RPM) 8 seconds (1 to 5000 RPM) (Underspeed mode)

Power Failure Protection

N/A Goes into alarm state on power failure

Bearing Life

N/A 10000 hr. @ 5000 RPM (lower with radial side load)

Set-point Stability

N/A ± 1.5 % (1 to 5000 RPM) ± 3 % (0.1 to 500 RPM) Nominal 32 ºF to 105 ºF (0 ºC to 41 ºC)

Set-point Resolution

N/A 1 Digit

Set-point Hysteresis

N/A 10 % (1 to 5000 RPM) 20 % (0.1 to 500 RPM)

Operating Temperature Range

N/A -22 to 150 ºF-30 to 66 ºC

Shaft Torque Required

N/A 4 oz/in0.0029 kg/m

Maximum Continuous Running Speed

N/A 5000 rpm

Direction of Rotation

N/A Either - No Effect

Maximum Radial Load

N/A 50 lbs22.7 kg

Case Construction


Speed Switch Features


  • Unique direct digital set-point adjustment
  • Built-in tachometer readout of speed
  • Start up delay in underspeed mode
  • Output state indicator alarm (output "ON" or "OFF")
  • NEMA-4 enclosure of cast aluminum and steel housing
  • 5/8" shaft with double race ball bearings
  • Only one moving part
  • Operates reliably in "hostile" environments
  • Trouble-free solid-state circuitry
  • Either AC input/output or DC input/output as specified
  • Available with C-face flange or standard-foot mount
  • Fast response (1/16 or 1/60 turn depending on model)
  • Matching stub shafts and flex couplings available

Switch Operation

N/A This rugged, completely self-contained NEMA-4 switch is a rotary shaft speed detector and tachometer. It will electronically detect either underspeed or overspeed. This is accomplished by set-point selection done directly thru pushbuttons and is displayed on the LCD readout. The actual shaft speed can be displayed on the LCD by a simple push of a button.

When the shaft speed on a piece of equipment exceeds or falls below the set-point speed, change is immediately detected and output is provided via relay contacts to actuate motor contactors, audible alarms, warning lights, PLC's etc. Maximum response time is the time required to rotate 1/16 of a turn at the set speed for a standard unit, or 1/60 of a turn for the high response option, after the shaft passes through the set speed. The output condition is displayed as "ON" or "OFF". When "ON" is displayed, the driven speed exceeds the overspeed setpoint, or is below the underspeed set-point. The output relay is de-energized in this condition and the "Alarm" contact (N.C.), closed in the output relay. The ESS also falls into this condition under loss of power providing the logic that indicates "Alarm" under power failure to the ESS.

Speed Switch Applications


  • Bucket Elevators
  • Bulk material handling
  • Chemical processing
  • Conveyor systems (all types)
  • Food processing
  • Foundries
  • Mining Equipment
  • OEM applications
  • Paper Manufacturing
  • Power Plants
  • Rotary Airlocks
  • Saw Mills
  • Steel Mills
  • Special machinery

Important Note

N/A Custom Modifications available such as special shaft machining, diameters, mounting, finishes, supply voltage, etc.