Treadmill fuse blowing

Discussion in 'General Electronics Chat' started by tmn, Feb 9, 2015.

  1. tmn

    Thread Starter New Member

    Feb 9, 2015
    5
    0
    Please can someone here offer some advice

    I have a Raleigh Power Runner treadmill. The last time I went to use it it rapidly stated to speed up before cutting out. The control panel still works and so to does the incliner. However, the belt no longer moves.

    After opening it up I noticed the treadmill fuse (not the mains plug fuse) had blown. I replaced the fuse - the motor begins to rotate, I see a spark coming from the motor and then it cuts out and the fuse has blown again.

    I inspected the controller board and I can't see anything suspicious

    Has anyone got any idea of what might be the problem might be, please?

    Please see attached pic of controller board
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,979
    744
    sounds like the motor, brushes worn out, rotor damage, bearings .....
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,526
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    Sound to me a bit like the drive power devices are shorted?
    Try the motor on an automotive battery to see if it runs smooth with no sparking etc, both directions.
    Max.
     
  4. Reloadron

    Active Member

    Jan 15, 2015
    963
    232
    Looks like it would be relatively easy to remove the motor brushes (one brush cap is in the picture) and look them over. Also looks easy to remove the M= and M- leads from the board disconnecting the motor. Remove the M+ and M- leads and power it up. Does it blow the fuse? If less motor the fuses blow I would look board, if not I would look motor.

    Ron
     
  5. tmn

    Thread Starter New Member

    Feb 9, 2015
    5
    0
    I tried testing the motor with a drill battery.

    The first time I tried it I got the same spark. However, the second and third time I tried it worked normally (i.e. without a spark)

    Anyone got any futher suggestions?

    thanks
     
  6. Reloadron

    Active Member

    Jan 15, 2015
    963
    232
    Did you inspect the brushes? They should pop right out looking at the picture. Does the shaft spin freely?

    Ron
     
  7. tmn

    Thread Starter New Member

    Feb 9, 2015
    5
    0
    I tried it again connected to the mains and the fuse blew again.

    I was reluctant to inspect the brushes as I don't know much about motors.....however, I will have to check them now

    thanks
     
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Disconnect the motor and see if the fuse still blows, if so it is the motor control devices, SCR's, Mosfets or IGBT's etc.
    If the fuse remains in, test the motor on a automotive battery source as I suggested. Drill battery does not have the capacity.
    Max.
     
  9. tmn

    Thread Starter New Member

    Feb 9, 2015
    5
    0
    When I disconnected the motor the fuse did not blow. So it looks like it is a problem with the motor.

    I have now removed the motor. The brushes look okay - see attached photos. Has anyone got any further suggestions?

    Should I attempt to further dismantle it?

    I do know of a shop that would be willing to look at it for me, give me a quote for repair (if possible) and then let me decide if I want to go ahead with the repair
     
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Did you try it on an automotive battery as I suggested?
    A limited test, but often will show any obvious characteristics.
    The other possibility is it could still be the board, you stated it sped up before failing, this shows it could be something turning the motor full on, if so it will blow the fuse on a good motor because the motor cannot react that fast, especially with a large flywheel.
    T.M.'s are designed for slow start.
    Max.
     
  11. IamJatinah

    Member

    Oct 22, 2014
    70
    14
    Motor control board. brushes cannot cause runaway, the HEXFET is shorted now, disallowing the motor rail. Contact jatinah electronics if you need repairs.
     
  12. tmn

    Thread Starter New Member

    Feb 9, 2015
    5
    0
    I got an electrical company to look at it. They inspected the motor and said the armature had gone. They said I would be looking at about £300 for a rewind so I decided to get a new treadmill.

    I put the working parts of the old treadmill up on ebay.
    Thanks for everyone's feedback
     
  13. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I have picked up motors on ebay for ~$50.00.
    Max.
     
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