MOTORSCOPE

don't start your electric motor without one...

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Fault Finding
The motor is running and all is okay.
Symptom or Reason
  • Motor does not start.
  • The Motorscope unit does not switch on.
    (no indication lights)
Remedy
  • Measure the AC voltage between live and earth. This should be between 190 and 250 volts.
  • Measure the AC voltage between neutral and earth. This must not be more than 5 volts.
  • Disconnect the power and then measure the resistance of the primary winding of the transformer on the Motorscope unit. (±1.5k Ω)
  • If the above steps does not reveal the source of the problem, try to switch the live and neutral wires.
  • Measure the AC voltage between each one of the phases and earth. This should be ±220 volts.
  • Disconnect the power and then measure the resistance of the primary winding of the transformer on the Motorscope unit. (±5k Ω)
  • Make sure that the on/off switch is working, by measuring its continuity.
Symptom or Reason
  • Phase sequence incorrect
  • Phase failure
Remedy
On three phase units only:
Swap two incoming phase wires at the isolator.
Symptom or Reason
  • The supply voltage is more than 15% lower OR 11% higher than the rated operating voltage.
Remedy
  • Measure the AC voltage between live and earth.  This should be between 190 and 250 volts. 
  • To improve the voltage measurement of the Motorscope unit, the earth wire must be removed and the neutral and earth terminals of the Motorscope unit must  be bridged.  
  • Measure the AC voltage between each one of the phases and earth. This should be ±220 volts.
  • If all of the phase measurements to earth is ±220 volts, the voltage measurement of the Motorscope unit can be improved by placing a bridge between the earth and COM terminals of the Motorscope unit.

NOTE:
  • When the supply voltage recovers and stays within the safe limits for 15 min, normal operation resumes.
Symptom or Reason This error occurs at calibration of Three-phase units if the phase-angle is larger than 60°.
Remedy
  • Make sure that all of the valves in the pipe-line from the motor are OPEN, then try calibrating again
  • If the unit has an external CT, make sure that the CT is in the phase marked on the unit as L3.
  • If the pump (wet-end) is smaller than the motor (dry-end) then the phase-angle is higher than normal.
    If this is the case and it is not possible for you to fix it by fitting the correct size pump to the motor, then you can bypass this error by contacting us and using an Optimizer.
  • If the Motorscope unit continues to trip in this error, even when the bore-hole's water level is restored, the pump should be pulled out and inspected.
Symptom or Reason Broken shaft or belt
Blocked pump inlet or outlet
Remedy
  • A run-dry condition has occurred and the Motorscope unit will only restart after a manual reset (by switching the power off and then on).
  • The Motorscope unit can be restarted automatically if the underload restart timer is enabled.
  • If the Motorscope unit continues to trip in an Underload, even when the bore-hole's water level is restored, the pump should be pulled out and inspected.
Symptom or Reason Underload
Remedy
  • A run-dry condition has occurred and the Motorscope unit will automatically attempt to restart the motor after the underload timer has run out.  The timer may be adjusted on the Motorscope unit. 
Symptom or Reason The state of a peripheral device connected on the AUX port of the controller changed and thus caused a trip.
Remedy
  • Verify that the peripheral device is active. If so, the Motorscope unit is functioning correctly. The Motorscope unit should automatically restart the motor once the peripheral device returns to its previous state. If the trip occurred during the wrong state of the peripheral device, the Optimizer may be used to alter the passive state of the peripheral device from "normally closed" to "normally open" or vice-versa.
  • Verify that the wires at the AUX and COM connections are securely fastened.
The functionality of the auxiliary input may be tested by placing a bridge between the AUX and COM terminals of the Motorscope unit.
Symptom or Reason
  • No current is measured.
  • The phase which goes through the current transformer might have a dry-joint.
Remedy
  • Verify that the wires from the Motorscope unit to the motor are properly connected.
  • Verify that the contactor pulls in. If the contactor does not pull in, verify that two different phases are connected over the coil of the contactor.
  • On three phase units with an external CT:
      Ensure that L3 runs through the current transformer (CT).
Symptom or Reason According to the motor manufacturers, a set number motor starts per time period shall be allowed to prevent the motor from over-heating.
Remedy
Wait for the T(Temp) timer to run out.

The first restart attempt after an Over Current or Over Power error would cause a fixed 30min restart delay to allow enough time for the motor to cool down.

The TTemp timer may be disabled with the Optimizer, but in doing so you will forfeit all rights on warranty claims, as the motor could then be used outside of its safe operating conditions.
Symptom or Reason The motor has drawn more current than the calibrated limit.
Remedy
Verify that the correct size motor is fitted to the controller.
There are different controllers for different motor sizes depending on the amount of current which is drawn under normal running conditions (as specified by the motor manufacturers).
Verify that the resistance over the external current transformer is correct (refer to the External C.T. Resistor Table on the last page of this guide).
The phase angle may be viewed with the Optimizer.
A phase angle lower than 27 degrees indicates an overloading motor, or a low voltage at the motor.
Verify the current, if that is correct then verify the wire diameters.
Refer to the Cable Diameter Tables at the bottom of the page.
Measure the current in each one of the wires going to the motor, while the pump is running.
If any one of the currents exceeds the motor's rated current, it is usually an indication of either a jammed pump or a damaged motor bearing.
Verify that all the wires to and from the contactor are securely fastened.
  • Disconnect the motor's wires from the contactor.
  • Number them 1, 2 and 3.
  • Measure the resistance between 1 and 2, 2 and 3, 1 and 3.
  • If any of these measurements exceeded 300 Ω, one of the cables is broken or most probably has a dry-joint.
Symptom or Reason See Overload for possible reasons
Remedy
  • Wait for the overload delay timer to run out.
  • The Motorscope will automatically attempt to restart the motor after 30 min.
  • However, if three consecutive overload errors occurred, it will not attempt to restart the motor again and an overload error will be indicated.
Only applicable to SINGLE PHASE units
Symptom or Reason Motor wires swapped
Remedy
Run, Start and Common Wire Definitions 1. Four wires go down to the motor. Number them 1, 2, 3 and 4.
2. Measure and take notes of the resistance from: 1→2, 1→3, 1→4, 2→3, 2→4, 3→4.
3. The Earth wire is not connected to any of the motor wires ("O.L" on multi-meter).
4. The highest value of the other three measurements is between the Run and Start windings.
5. The other wire is Common.
6. Run is the wire with the lowest resistance from Common.
7. Start is the wire with the highest resistance from Common.
This table is intended as a guide only.
Final values must be confirmed with the cable manufacturer.
Maximum submersible copper cable lengths in meters from Power Source to the Motor.
All lead out cables must be submerged.
400V Cable Selection Guide
Information was obtained from Franklin Electric spreadsheet.
This table is intended as a guide only.
Final values must be confirmed with the cable manufacturer.
Maximum submersible copper cable lengths in meters from Power Source to the Motor.
All lead out cables must be submerged.
230V Cable Selection Guide
Information was obtained from Franklin Electric spreadsheet.