E28 : High Motor Current

  • Something in the drive system broken (locked up pump, broken gear, etc.) not allowing the motor to rotate, causing high current
  • Possible short in the motor control board
  • On E-20/E-XP1 machines only, faulty high pressure switch or loose jumper connection on pin 7 to 10 of connector J10 of the motor control board. See E23 error causes section.
    •  Check to see if the failure is on the motor control board or if it is within the motor.
    • Turn the main power switch off.
    • On the motor control board disconnect socket J4 (E-20/E-XP1) J1 (E-30/E-XP2).
    • Turn the main power switch back on.


Did the E28 Error go away?

  • If the E28 error did not go away then there is a problem with the motor control board and/or the motor drive system.

Replace the motor control board after thoroughly checking the motor drive system. (See “Motor and motor drive check procedure” under E-series Reactor E3

  • If the E28 error went away then there is a problem with the motor, or motor drive system.
  • Check to see if the motor rotates freely. No binding of pump line gearbox assembly.
  • Check to see if the brushes or motor commutator surface is damage.
  • Check and make sure the voltage going to the motor is good.
  • Verify the motor will run with a 9 vdc battery.
  • On E-XP2 and E-30 machines verify capacitor is functional.
  • Check the three wire (yellow, yellow, orange) motor connector to the motor board.  A gentle tug on each wire individually at the connector should ID the loose wire.  If a wire pulls out, bend the locking tab on the crimp end, insert the wire until it seats and repeat gentle tug.

 If the above does not resolve the problem, replace the motor.