Electronic Speed Switches (Formerly Woodward)

ESSE switches monitor and control critical speed functions such as:

  • Crank disconnect or overspeed protection
  • Transmission shift inhibiting
  • PTO protection

The switches are adaptive to most speed-related switching functions on diesel and gas engines and other rotating machinery. In addition to generator sets, starter motors, and engines, ESSE switches are also used on diverse equipment such as conveyor belts, bus doors, and magnetic brake retarders.

Both single and dual setpoint models are potted for protection against harsh environments and have proven to be reliable and rugged as well as flexible and cost effective.


  • Standard or reverse relay operation
  • Field adjustable set and reset switch points
  • High noise immunity
  • Latch, automatic, manual or adjustable resets
  • Reverse polarity protection
  • Variety of speed signal input