Murphy’s ML2000 control panel automates consistent manure management.

When a farm housing 80,000 hogs on over 4,000 acres faced a manure pumping engine breakdown, MurCal experts stepped in with critical guidance and equipment. An operation of this size supplies products to hundreds of meat distributors across the United States.

A farm that moves 5,000 hogs through its system each week must consistently keep manure moving out of the feedlots to stay compliant with state and federal regulations. The health of its animals and the integrity of its products depend on clean lots.

Manure Pump Breakdowns Need Quick Attention

Farm managers are battling the clock when manure pumps fail. In this case, the farm had just had a new control panel installed by a local engine service company. The farm operator explained that they had bought MurCal’s ML2000 control panel to replace an old panel that could not maintain proper speed. With the new panel installed, however, no speed signal was reaching the controller in the panel. This information told our MurCal expert that testing the speed sensor would reveal important information.

When determining the integrity of the speed sensor, the operator can measure its resistance by disconnecting the pickup leads and checking the sensors with an ohmmeter. (It’s important to check the manufacturer’s specifications for acceptable values.)

The output voltage of a magnetic pickup is affected by these factors.

• ● Output voltage increases with increases in the surface speed of the flywheel teeth.
• ● Voltage decreases as the air gap between the magnetic pickup and the flywheel teeth increases. (The optimum air gap is typically 0.020” to 0.025” {0.5 to 0.65mm})
• ● The voltage waveform is determined by the size and shape of the gear tooth in relation to the size and shape of the sensor's pole piece.
• ● The resistance should be over 1000 ohms, between the magnet and the grounded threads

With these parameters in mind, we stayed on the phone with the farm manager and asked him to:

• 1. Measure between the pickup case and leads with an ohmmeter for near-infinite resistance.
• 2. Confirm there were no open circuits, including the wiring harness and all connectors.
• 3. Inspect the sensor for mechanical damage and remove any debris that might have accumulated on the pole piece.
• 4. Reset the air gap to 0.020” to 0.025” (0.5 to 0.65mm) and confirm that the sensor outputs a minimum of 1.0 VAC at cranking across the inputs to the speed control.

Upon determining that the speed sensor was bad, we were able to equip him with a new MP 7905 Magnetic Pickup, help him get it installed, and get the unit running.

Operation instructions and wiring diagrams are available on the MurCal website.

With our expert on the phone, the customer explored more efficient features of the ML2000. This controller is part of the Murphy PowerCore family and was developed to meet the need for manual or automatic control whether it’s starting/stopping, throttling, or both. It also has the flexibility to be used on either mechanically or electronically governed engines supporting SAE J1939 CAN communications.

Together, we configured the unit to run on floats. Then, after sending the operation instructions and wiring diagram (which are available on our website), we determined that this customer needed to introduce a level transducer.

We walked him through making changes in the menu, demonstrating its easy interface. We also set the level start and stop points, allowing the pump to be automated so that nobody needs to turn it on or off. The customer appreciated having a built-in warm-up timer which causes less wear on the engine. Together, we listened to the engine throttling up to the run set point, a happy ending to a frustrating situation.

With these calibrations, the farm manager was able to manage pump speed more easily because the system is fully automated. The farm now saves money on fuel by not having to shut off the system when the level goes down. Best of all, the new controls mean breakdowns and work stoppage is rare, alleviating headaches for the crew and costly downtime for the farm.

MurCal can help you customize your industrial, off-highway, and marine engine applications. Shop for parts here, or contact our experts to help strategize for your specific application.