Specifications

38
Service & Parts Manual original Instructions
Part Number 32Z3839 GB
Issue 5
Service & Parts Manual original Instructions
Part Number 32Z3839 GB
Issue 5
39
SW1
SW2 SW3
SW3
L1
N
SW1
SW2
L1
N
TESTING
COMPONENTS
TESTING
COMPONENTS
6
5
3
2
1
SW1
SW2
SW3
A
1
2
3
32
U
L1
DC
1
2
3
4
5
6
7
8
9
10
V
L2/N
W
L3
PE
64
67
66
68
65
19 MAINS VOLTAGE COMPONENTS
19.1 Door Interlock Adjustment
Located on the door hinges are 3 safety interlock
microswitches, to prevent microwave emissions
escaping when the oven door is opened:
The Primary (SW3) breaks the electrical supply
circuit to the transformers.
The Secondary (SW2) breaks the microwave circuit if
the primary fails.
The Monitor switch (SW1) will short out the
Microwave circuit blowing the fuse if both Primary
and Secondary interlocks fail.
IMPORTANT: in the event that the Monitor
switch causes the Microwave circuit fuse to
blow, the Secondary (SW2) and Monitor (SW1)
microswitches must be replaced due to exposure
from high short-circuit currents.
The purpose of the following adjustment procedure
is to set the interlock to switch o the Microwave
circuit when the door is opened more than 4mm
and for the Microwave circuit to operate when the
door is closed and the door seal expands.
19.1.1 Door Interlock Adjustment procedure:
19.1.2 Disconnect and isolate the oven from the
electricity supply.
19.1.3 Allow the oven to cool down.
19.1.4 Remove the oven casing.
19.1.5 Ensure that the High Voltage Capacitor is
discharged before commencing work.
1 Position Green 2mm spacers over the top
corners of the door seal and carefully close the
door ensuring the spacer is still in position.
2 Slacken the pivot screw.
3 Release the adjusting screws and move the
backplate until microswitch SW3 just activates
then secure all screws.
4 Open door to replace the Green 2mm spacers
with Red 4mm spacers and close the door.
5 Slacken the pivot screw.
6 Release the adjusting screws and move the
backplate until microswitch SW2 just activates
then secure all screws.
7 Remove the spacers, then open and close the
oven door 5-10 times.
IMPORTANT: CHECK THE SWITCHES OPERATE IN
THE FOLLOWING SEQUENCE AS MICROSWITCH SW3
MUST SWITCH THE LOAD CURRENT.
Closing the door:
● SW1 opens rst
● SW2 closes second
● SW3 closes third
Opening the door:
● SW3 opens rst
● SW2 opens second
● SW1 closes third
OVEN DOOR OPEN
OVEN DOOR CLOSED
19.2 Convection Fan Motor & Controller
19.2.1 Convection Fan Motor.
The convection motor is a 3-phase AC motor having
a maximum speed of 3500 rpm controlled by a
motor speed controller.
The windings are thermally protected.
19.2.2 Motor Controller
Provides a 3-phase AC switched mode drive to the
convection motor and is controlled by a 0 - 10 Volt
signal from the SRB. This allows the motor to be
adjusted from approximately 400 rpm to 3500 rpm
in steps of 5%.
● Door Open, 1000 RPM (30% @ 3V)
● Door Closed (not cooking), 1000 RPM (30% @
3V)
● Door Closed (cooking), speed as specied by
program or setting up to a Maximum of 3500
RPM, 100% @ 10V)
19.2.3 LED Status display (A):
● Inverter O/No supply, LED OFF.
● Power On/Ready, LED ashes ON/OFF x1 per
second.
● Inverter Running, LED ON continuously.
● General Warning, LED ON/OFF x2 per second.
● Fault Condition, LED ON/OFF x10 per second.
Convection Fan Motor & Controller tests:
19.2.4 Disconnect and isolate the oven from the
electricity supply.
19.2.5 Allow the oven to cool down.
19.2.6 Remove the oven casing.
19.2.7 Ensure that the High Voltage Capacitor is
discharged before commencing work.
19.2.8 Check the following:
1 Electrical supply into motor controller.
2 Three phase connections to motor.
3 Speed Controller connections to SRB.
4 Motor rotates freely/not seized.
5 Motor winding resistances:
● Blue-Black 35 Ohms.
● Black-Brown 35 Ohms.
● Brown-Blue 35 Ohms.
● Black or Brown or Blue to Earth (Open circuit).