Service manual

12. Functions sequences

Service

manual

487 03 29 91

12.4

Circuit diagram 489 50 01 77 has been used in describing the function sequence in this

section: This diagram is in principle identical to all the other circuit diagrams since the

control voltage is 24 V AC 50/60 Hz.

Start of extraction

The machine starts extraction when the operator presses the START button on the

control panel.

Drive motor M1 is energised via connection X3-X5 (star connection) or X2-X7(delta

connection) when relay K1 operates. For K1 to operate, the following conditions must be

fulfilled:

• The lid´s Reed element R1-R2 must be activated, e.g. the lid closed (this does not

apply to the C290R, which has no Reed element in the lid).

• The mechanical lid switch (SW1) must be activated (lid Closed).

When the lid´s Reed element closes, a signal (GND potential) is obtained at terminal

OUT1 S3 on connection S3. This signal is supplied via the circuit board to terminal

GND2 on connection S6. Terminal OUT2 on S6 will have GND, potential, which

allows the extractor to start.The logic circuit will now supply control voltage to terminal

S1:4, which via an interlock contact on brake relay K2 supplies one side of relay coil

K1. The other side of the relay coil receives voltage from S1:2 via lid switch SW1 and

the motor´s internal thermal protection F3.

When K1 operates, an interlock contact in the control circuit opens to relay K2 (brake

relay), thereby preventing K2 from operating at the same time as K1.