A91 Panel Systems

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.


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

  • Notes

    ower Input: 12 or 24 VDC nominal (specify).

    Standby Power Consumption: <50mA.

    Magnetic Pickup Input: Requires 2 V rms minimum.

    Sensor Input Polarity: Negative (-).

    Outputs: Five (5) open collector transistor 500 mA sink.
    Two (2) relay, 5 Amp maximum at 12 or 24 VDC (sourcing).

    Reverse Polarity Protection: 200 volt peak reverse voltage.

    On-board Memory: 8k PROM (programmable, read only memory); data retention 10 years.

    Operating Temperature Range: -20 to 140°F (-25 to 60°C).

    Operating Humidity Range: 0-95% Non-Condensing

    User Trip point Adjustments: Five (5) on-board potentiometers (320° turn).

    Test-Off-Automatic Toggle Switch: Three position switch for:

    • Test: Starts engine in automatic mode and runs until switched “off” or emergency shutdown occurs.
    • Off: Disconnects all power to control circuits, Stop/disables engine from starting and resets shutdown indicators.
    • Auto: Automatic start/stop sequencing is initiated by external switches and signals.

    Cycle Crank Timer: 5 crank attempts 7 seconds each; 4 rest periods 15 seconds each, before overcrank.

    Overspeed Trip Point Setting: From 2500-9000 Hz.

    Crank Disconnect Speed Setting: From 400-2500 Hz.

    Shutdown Time Delay: 15 seconds after engine start; locks out low lube oil and high temperature.

    Engine Run LED: Turns“on”when crank disconnect occurs.

    Shutdown Output: Removes DC output or operates dry relay contacts for engine shutdown (depending on model used).

    Start/Stop: SPDT momentary; or SPST maintained switches.

    Warmup Time Delay: Field adjustable from 0-300 seconds to load the engine after warmup (model -WC only).

    Cooldown Time Delay: Field adjustable from 0-300 seconds (model -WC only).

    Enclosure: Weatherproof NEMA 3R.

    Enclosure Coating: Red enamel.

    Subpanel Coating: White enamel.

  • Downloads

Service done right

Murphy by Enovation Service Network

Palmer Johnson's six-location factory-authorized service center network features:

  • Factory-trained technicians
  • Field service
  • Onsite troubleshooting and diagnostics
  • Unit removal and installation

For Murphy by Enovation service, call 1-800-341-4334.

Learn more

Madison, WI

Service Center

Service: (608) 834-5206

1835 Haynes Dr
Sun Prairie, WI 53590


Dallas, TX

Service Center

Service: (817) 505-2430

608 112th St
Arlington, TX 76011


Denver, CO

Service Dealer

Service: (720) 724-0033

5151 E 56th Ave
Commerce City, CO 80022


Kansas City, KS

Service Center

Service: (913) 202-6944

15360 South Mahaffie St
Olathe, KS 66062


Los Angeles, CA

Service Center

Service: (562) 356-1590

12020 Bloomfield Ave
Santa Fe Springs, CA 90670


Oklahoma City, OK


Sales: (800) 341-4334

Oklahoma City, OK 73128


Phoenix, AZ

Service Dealer

Service: (602) 253-0214

2401 S. 19th Street
Phoenix, AZ 85034


San Francisco, CA

Service Dealer

Service: (510) 342-2212

1930 W Winton Ave #14
Hayward, CA 94545


St. Louis, MO

Service Center

Service: (636) 203-9811

578 Rudder Rd
Fenton, MO 63026


Philadelphia, PA

Service Dealer

Service: (215) 822-8300

159 Discovery Dr
Colmar, PA 18915


Fort Myers, FL

Service Dealer

Service: (239) 693-7477

4821 Waycross Road
Fort Myers, FL


Vancouver, British Columbia

Service Center

Service: (604) 879-6731

6741 Cariboo Rd Unit 205
Burnaby, British Columbia V3N 4A3


Edmonton, Alberta

Service Center

Service: (780) 434-9578

3804 53rd Ave NW
Edmonton, Alberta T6B 3N7


Seattle, WA

Service Center

Service: (425) 251-3434

1710 136th Ave E Suite 200
Sumner, WA 98390


RECON Equipment Center, WI

Service Center

Service: (608) 834-5220

1828 Haynes Dr
Sun Prairie, WI 53590

Map of Palmer Johnson Power Systems locations