Murphy A91 Engine Controller
  • Murphy A91 Engine Controller

A completely unattended startup/shutdown and run controller for engine driven equipment. This user friendly, compact, state-of-the-art microprocessor based controller, covers all basic start stop operations plus other features only found on more sophisticated and expensive controllers.

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A91 is Microprocessor Based Automatic Controller feachuring:

  • Field Programmable Trip Points
  • Five LED Signal Indicators
  • Startup Lockout Timer
  • Interfaces With Other Existing Murphy Products
  • NEMA 3R “Weatherproof” Enclosure

 

A completely unattended startup/shutdown and run controller for engine driven equipment. This user friendly, compact, state-of-the-art microprocessor based controller, covers all basic start stop operations plus other features only found on more sophisticated and expensive controllers.

The A91 is designed to operate from a 12 or 24 volt battery, and requires a magnetic sensor (pickup) for speed detection. It includes features, such as crank and rest cycles, time delay lockouts, sensing circuit for crank disconnect and overspeed, time delays before start and stop. Warmup and cool down are connected only on the WC model. Four LED’s indicate shutdown for: low lube oil, high temperature, over crank and overspeed, and are reset by turning the power off. A fifth LED for engine running indicates when crank disconnect occurs.

The micro-controller is available in several configurations and is factory programmed. Certain parameters can be field adjusted without altering the basic control program. Custom programming of the microchip is available to OEM’s and quantity orders.

The A91 is housed in a NEMA 3R enclosure with a hinged and gasketed dead front door. This weatherproof enclosure includes two 1/2 in. conduit holes, [7/8 in. (22 mm) diameter] in the bottom for input and output wiring.

All of the electrical components are installed on a “box” shaped, hinged front sub panel assembly. This working assembly can be purchased and installed in the user’s choice of enclosures.

  • A variety of applications can be covered with the micro-controller such as:

  • Air/Gas Compressors

  • Standby Generator Sets

  • Fire/Pipeline/Emergency Flood Pumps

  • Booster/Transfer Pumps

  • Municipal Fresh/Waste Water Treatment

  • Sewage Lift Stations

Available Models

A 91: For less than 5 amp current draw up to 24 VDC electric run output*

A91-S: For 10 amp current draw up to 240 VDC electric run output*

A91-WC: Same as A91—with a warmup/cooldown relay.

A91-S-WC: Same as A91-S—with a warmup/cooldown relay.

Any Model -LC: Less weatherproof enclosure.

*Run output is the voltage and current required for an ignition system, fuel valve, or solenoid actuator that allows the engine to run.


Features


The A91 Series combines the advantages of solid state microprocessor control logic with the dependability of Murphy’s experience in Engine Automation Systems. This engine controller eliminates the need for most electromechanical logic and control relays, while providing built-in design features:

  • Applicable to All Types of Engines
  • Built-in Speed Sensing Circuit with:
    • Adjustable Crank Disconnect RPM
    • Adjustable Over speed RPM
  • Three-position Selector Switch allows for “Automatic”, “Off” or “Test” mode.
  • Engine Running LED indicator
  • Four First-Out Shutdown LED indicators for:
    • Low Lube Oil
    • High Temperature
    • Overcrank
    • Overspeed
  • Quality 16 point Terminal Block
  • Either start from remote contact close to start, open to stop, or N.O. contacts close to start, close to stop.
  • Relays are plug-in type with LED indicator for fast service and maintenance.

Optional Features
-S: Includes a relay to isolate magneto and capacitor discharge ignition systems.
-WC: Includes a relay for loading and unloading driven equipment for engine warmup and cooldown.