AT03069 Murphymatic Engine Throttle Controller

The AT03069 is a completely reliable heavy-duty device developed specifically to automatically control engine speed to meet system demand.

Low current, high torque, solid-state switching and an electronic clutch make it ideal for all automatic and semiautomatic engine systems. Used with the appropriate Murphy Swichgage® near constant pressure, level and load can be maintained. Speed changes are made slowly and smoothly.

The device saves fuel, engine wear, horsepower and labour. One model can be used with both 12- and 24-VDC systems. Check with our engineers for help with other applications where speed control can improve your system.

Applications include:


  • City water systems
  • Water flood injection
  • Sprinkler lateral changes
  • Make-up if a gang pump stops
  • Multiple hose-reel irrigation systems


  • Water or oil storage tanks
  • Waterflood tanks
  • Sewer disposal systems
  • Flood control catch basins


  • Multi-engine cooling systems
  • Air conditioned chilled water systems

Engine load

  • Empty or fill reservoirs with a lower horsepower engine — fast when head is high— slow when head is low

The AT03069 can enhance features of our Powercore Controllers by allowing features such as:

  • Warm-up RPM set point
  • Minimum RPM set point
  • Maximum RPM set point
  • Preset operating RPM set point
  • Auto throttling to match flows (as needed in flood control applications)
  • Maintaining system pressure (as needed in booster station application)
  • Adjustable rate of change in RPM (allowing fine tuning of overall system)


Spec Bulletin