DIYbanter - View Single Post

Andrew Gabriel

In article . com,
writes:
Washing machine (Hoover ws130) has developed a fault in that whenever
it tries to turn the motor, the motor runs at full speed. This means it
cannot wash and even on spin it spins for a few secs then stops. I have
seen the motor reverse. Reading around suggests that either the tacho
may be at fault or more likely that the triac has failed and is keeping
the motor at spin speed. Is there anyway of testing the triac to see if
this is the case. Or is it a case of trying a new one? I can source the
part (BTB08-600BW) and I get the impression that failing triacs are
common. Is this true? My concern is that if I call in the repairman he
will just recommend a new control board/timer which would be costly to
the degree that I would consider a new machine.

A replacement triac is under £1, so you could just swap it,
if you have the relevant electronics skills. (You can probably
use a BTA08-600 which is easier to find. It has an insulated tab
whereas the tab on yours is live, providing yours isn't using
the tab as one of the electrical connections.)
Use new heatsink compound.

The symptoms you describe are not what I would expect from a
failed triac though. If the triac had shorted, I would expect
the motor to run continuously, but maybe that washing machine
has some other means to disconnect the motor when not being
used.

A warning if you are testing this... Never let a washing motor
run at full speed with no load and no servo control. Many of
them can spin fast enough for the armature to explode when not
properly speed controlled.

--
Andrew Gabriel