Why is the Fault Light Active on the Solar Pump Controller?

The Fault light is a general error indicator for the following conditions:

• Wiring issues
• Overload
• Overheating
• Short circuits
• Motor startup failure

The controller is stopping the pump to protect it from damage.

Sometimes faults are momentary and can be caused by several things (e.g. debris, power surge, etc.). Perform a hard reset to clear the fault and get the pump running.

• With the pump stopped and not running, turn the solar isolator OFF
• Wait 30 seconds
• Turn it back ON
  This will reset the controller and can clear temporary startup issues.

If the Fault light stays ON, continue to the steps below.

Faults are often caused by incorrect or loose wiring between the controller and pump. Check that the motor’s power cable wires are connected to the U, V, and W terminals according to the labels on the wires.

Do not copy any previous installations or colour matching. If you are unsure, compare the labels on the individual wires and the labels of the pump controller’s terminals. You can also refer to the installation guide in the user manual.

• Open the controller and ensure wires are in the correct order based on labels.
• Check that the wires are securely connected to the UVW terminals.
• Look for signs of:
  • Loose wires
  • Burnt terminals, connections, or wires
  • Corroded terminals, connections, or wires
  • Tighten any loose terminals and reseat wires if needed.

Failed bearings can prevent the motor shaft from rotating, causing it to draw a lot of amps and triggering the Fault alarm.

• To check for failed bearings:

• Remove the pump from the water or disconnect the water inlet pipe.
• Separate the motor from the pump.
• Check that the motor shaft can turn freely with a clunking sensation as it is turned. The clunking sensation is the motor shaft’s magnets moving between the windings and is normal.

Sometimes, a failing rotor and stator can become tight and cause the pump motor to draw a lot of amps and triggering the Fault alarm.

• Inspect the inlet screen for grass, reads, or plastic wrapping and ensure the pump is not drawing in mud or grit from the water source.

5a. Submersible Screw/Helical Rotor Pumps (e.g. bore pumps):

These pumps contain a rotor (metal screw) and a stator (rubber sleeve) that wear out and can become tight over time.

• The rotor and stator (impeller) should be replaced every 1–2 years depending on your local water conditions (e.g. grit or mineral content).
• Remove the pump from the water and check:
  • The rotor can turn freely inside the stator.
  • If it has become tight, swollen or the rubber has hardened, it can stop the motor shaft from rotating.

5b. Centrifugal Multistage Pumps

These pumps have multiple spinning impellers can become clogging or damaged and affect their rotation.

• Check the side walls of the impeller stages for damage.

• Check the inlet screen and impellers for blockages (grass, reads, algae, etc.).
• Running the pump backwards can help clean out the impellers if they are not badly clogged.
  • Run the pump backwards for 5–10 minutes.
  • Switch back to forward for 5–10 minutes.
  • Then reverse again one more time.

To reverse the pump’s running direction:

1. Turn the solar isolator off.
2. Open the controller and take a photo of the pump’s power cable wiring.
3. Swap the wires on the V and W terminals with each other.
4. Turn the solar isolator on.

Note: Be cautious and contact Commodore Australia if you are unsure of this process.

If the impellers remain clogged, you may need to disassemble and clean the pump.

• This involves removing and reassembling multiple internal parts in the correct order.

• Contact Commodore Australia on 1300 669 256 for detailed guidance.

5c. Single impeller Centrifugal Pumps

These pumps have a single spinning impeller that can be sensitive to clogging. To check the impeller, you will need to disassemble the pump to access the impeller for cleaning.

Contact Commodore Australia on 1300 669 256 for detailed guidance on your specific pump model.

If the pump controller has been running in direct sun light or drawing too much power, the controller may overheat and trigger a fault.

With the pump stopped:

• Turn off the incoming power at the isolator switch and let the controller cool down for 15–30 minutes, then try restarting.
• Ensure the controller is:
  • In the shade or in a well-ventilated area.

• Not enclosed in a hot box.

Short circuits or excessive current draw (overload) may trigger the fault alarm.

These can be caused by:

• Loose, damaged or corroded connections.
• Incorrect solar array configurations.
• Miss matched pump controller’s and motors.
• Water shorting out cable joins.
• Water shorting out motor windings.

Things to check:

• That the pump size matches your pump controller’s specifications.

• 24V pump motors are paired with 24V pump controllers.
• 48V pump motors are paired with 48V pump controllers.
• 72V pump motors are paired with 72V pump controllers.

• Inspect Solar Wiring Connections:
  • With the pump stopped, turn off the incoming power using the isolator switch.
  • Check that the solar panel wires are securely connected to P+ and P- terminals.

• Check the P+ and P- terminals for loose wires, burnt connections, and corrosion.
• Check the solar input cables and connectors for signs of melting or heat damage.

• Test the Solar Panel Voltage to confirm that the solar panel configuration is correct:
  • With the incoming power turned on, use a multimeter to check the voltage at the P+ and P- terminals:
    • 24V pump systems should show 35V–55V open circuit voltage (Voc)
    • 48V pump systems should show 65V–109V (Voc)
    • 72V pump systems should show 80V–140V (Voc)
    • If the voltage is outside the range for your pump and controller, contact Commodore Australia on 1300 669 256 for further assistance.
  • Inspect the pump power cable and connection:
    • Check that the pump power cable wires are securely connected to the UVW terminals.
    • Check the UVW terminals for signs of loose wires, burnt connections, corrosion.

• Check the pump power cables and connections for signs of melting or heat damage.

If water has penetrated the cable join, it could be causing a short on the pumps power cable. It can also get into the motor and be causing a short on the motor’s windings.

To test the pumps power cable for shorting, follow these instructions:

1. Turning off all incoming sources of power to the pump controller.
2. Remove the 3 wires of the pump’s power cable from the UVW terminals.
3. Bend the ends of the wires so they have a hook and can sit on the multimeter probes.
4. Turn your multimeter to the 200 Ohms/Ω setting and touch the probes together. This should give a 0 reading. If there is a number or OL, it is possible that the multimeter will not work correctly.
5. Take 2 wires and place one on each probe. For example, place the Brown wire on the Red probe and place the Blue wire on the Black probe. Test all 3 combinations of 2 wires and write down their values.
6. If the numbers are more than 0.3 ohms in difference, there is likely a problem with the pump’s power cable or motor.
7. If there is a cable join, you can cut the cable join out and test the remaining cable going to the motor.
8. If the readings are still too great in difference, there is likely a problem with the pump motor and needs to be sent in for testing.
9. Contact Commodore Australia on 1300 669 256 for further assistance.

Conclusion:

The Fault light tells you the system has shut down to protect itself.
Go through this checklist:

• Perform a reset.
• Check wiring (input terminals (P+ & P-), output terminals (UVW)).
• Check pump for blockages and jamming.
• Check the pump controller for overheating.
• Confirm solar voltage and configuration are correct.
• Check for short circuit or overload.
• Test pump motor for shorting.

If the light remains ON after all these steps, your controller or pump may need repairs or replacing. Contact Commodore Australia’s Technical Support team for further assistance.

Phone 1300 669 256 or email support@commodoreaustralia.com.au