Tumble - Variable Frequency Drive & Micro Test Procedure
The single red LED in the middle of the CPU PCB should be lit when the microprocessor has power
and is processing data. Red light flashing means it has power but is NOT processing data. Remove
power from machine for 2 minutes to reset board. If no red light, there is no power to the board.
This testing procedure should be followed. A DCM ground control circuit is used on this Variable Fre-
quency Drive. The white wire supplies a DCM ground through the Run relay contacts. When testing
this unit you will get a 24VDC reading when NOT calling for that action. A 0 VDC reading will show
when that rotation direction is called for. You must take the VDC reading between either two points
DCM and FWD or REV. (Remember - 0 Volts when calling for an extract or wash speed). The Variable
Frequency Drive also uses two braking resistors to dissapate the voltage generated after motion has
been signaled to stop. In these models they are both rated at 160 ohms. Please remember that when
testing these that a 160 ohms reading does not always confirm a good resistor. The resistors could
be breaking down under heat load. If these resistors are grounded or open they could possibly make
this unit malfunction.
Liquid Chemical Signals
Chemical injections signals are available in all bathes. If programmed, the following numbers will pro-
vide 120 VAC signals to the designated terminals on the back of the washer. All Chemical injections
signals are delayed until 30 seconds after the tub starts to fill with water. All signals are 6-10 seconds
in duration.
Intermediate Extract Circuit
Intermediate Extract can be programmed after all bathes except the Final Rinse (see Final Extract). If
programmed for Intermediate Extract, the Microprocessor will signal the Input/Output PCB to supply
a DCM ground (red output light #14 on Input/Output PCB will be lit) on the orange wire to the REV
terminal on the Variable Frequency Drive. This insures that the tub is turning the correct direction
before starting into spin. Next, the Input/Output PCB supplies a DCM ground (red output light #15
on Input/Output PCB will be lit) on both the red M13 and black wires M12 to the (intermediate spin)
terminals on the Variable Frequency Drive.
Final Extract Circuit
Same sequence as Intermediate Extract but adds the following. The Input/Output PCB supplies a
DCM ground (red output light #16 on Input/Output PCB will be lit) on the green wire to the (final
spin) terminal M11 on the Variable Frequency Drive. REV; M13; M12 ; M11 all 4 terminals are supplied
a DCM ground for high spin.
End of Cycle
At the end of the cycle, the Display PCB will read 0 minutes, the Beeper will sound for 5 seconds in
1 second intervals and the End of Cycle Light will come on. The washer door must be opened before
the display resets and allows a different cycle to be selected. You can run the same cycle again with-
out opening the door BUT you must open to reset to another cycle.
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Part # 8533-096-001 11/16
Part # 8533-096-001 11/16
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Section 5:
Machine Service
Procedures
