
46
Motor control unit
The motor control unit communicates with the program control unit board
via a serial (input/output) interface. With the aid of the motor control unit the
program control unit can control not only the speed of the motor at any
given point, but also the acceleration or deceleration rate at which the motor
is to achieve the speed required. The motor control unit constantly feeds
information on current status (both normal status and on any abnormalities
arising) back to the program control unit board.
The motor control unti can also supply data on the torque of the motor at
constant speed and when accelerating and decelerating. This data is used
both tor calculating the weight of the wash load and for detecting any
imbalance present.
WARNING
The voltage at test points 1-4 (TP1-4) has a potential difference of
approx. -100 V in relation to incoming neutral and ground. Because
of this, be careful when measuring. Use ungrounded oscilloscopes.
If the motor control unit has a green LED, this will remain lit for as
long as there are hazardous voltages present in components.
The motor control unit on the 100-litre machine has a cooling fan. The fan
starts automatically when the temperature reaches about 65
°
C which can
happen during extraction or if the surrounding temperature is high. When
the machine starts the fan is rotating for a short while.
Mechanical and electrical design
3715
69
Fig.
69
X 302
X 301
Green LED
Yellow LED
Fig.
70
X 312
Connections for
wash motor
Test point 2: 0V
Test point 3: 5V
Test point 4: 12V
X 311
Input voltage 220 V
Only on EX 25
machine