XL10 fan speed control relay burned

Discussion in 'General Electronics Chat' started by ratheepkrk, Apr 20, 2011.

  1. ratheepkrk

    Thread Starter New Member

    Apr 12, 2011
    Hi Friends.

    My XL10 controller have three relays to control the fan speed of fan coil unit
    fan coil unit have three speed low,medium and high
    Due to the over current from the fan coil unit my controller relay is going to burn, how can I find the source of over current. Is it related to the fan load?
  2. PackratKing

    Well-Known Member

    Jul 13, 2008
    Here's a guesstimate, based on your lack of information :p You gotta do better. Answer me this ::

    To what extent have you dismantled the fan housing ??? Is the fan direct-drive on the motor, or are there pulleys w/ a belt ??

    Does the motor / fanblade mounting seem rigid enough, and the fan blade turn freely by hand, and not drag on any part of the system.

    If the ductwork / fanblade is loaded with dust, or the fan won't spin freely by hand w/o power, you may have motor bearing issues.
    A lot of these motors have no means of adding lubrication to shaft sleeve bearings, and go bad over time,
    If the motor has drawn excessive current for too long, its stator coils could be scorched, in either case are usually not repairable.

    Any air-moving device, i.e. a squirrelcage fan, is built into a housing to restrict airflow to a proper level. In the event this housing is partially dismantled, or and baffles removed-- unrestricted airflow -- this will cause the motor to draw excessive current, which will burn out the whole thing in short order.

    Check these issues, and get back.
    Last edited: Apr 29, 2011