KitchenAid KHMS105E Service Manual page 10

The normally-closed (N.C.) contacts of relay 4 provide a potential circuit for the Base Thermal
Fuse (see the following strip circuit). If the base of the oven exceeds 133˚F, the thermal fuse
contacts close, and a circuit for the low-speed side of the blower motor is completed, which turns
the motor on. The low-speed blower will operate until the base temperature drops below 104˚F
and opens the thermal fuse contacts, and turns off.
L1
15A LINE
FUSE
BK
When the low-speed fan is selected by the user at the control panel, relay 3 and the normally-
closed (N.C.) contacts of relay 4, complete the circuit to the low-speed windings of the blower
motor and turn it on.
L1
15A LINE
FUSE
BK
When the high-speed fan is selected by the user at the control panel, the normally-open (N.O.)
contacts of relay 4 complete the circuit to the high-speed windings of the blower motor and turn
it on.
L1
15A LINE
FUSE
BK
BK
BK
BK
CAVITY MAGNETRON
THERMAL
THERMAL
FUSE
FUSE
BK
BK
CAVITY
MAGNETRON
THERMAL THERMAL
FUSE
FUSE
BK
BK
BK
CAVITY
MAGNETRON
THERMAL THERMAL
FUSE
FUSE
MICROCOMPUTER
BOARD
LOW-VOLTAGE
TRANSFORMER
RD
4
RELAY #4
MICROCOMPUTER
BOARD
LOW-VOLTAGE
TRANSFORMER
BK
RD
4
RELAY #4
RELAY #3
MICROCOMPUTER
BOARD
LOW-VOLTAGE
TRANSFORMER
RD
4
RELAY #4
1-2
W
1
CAPACITOR
R
Y
W
YL
7
BASE
BLOWER
THERMAL
MOTOR
FUSE
LOW
W
1
CAPACITOR
R Y
BR W BL
6
BLOWER
MOTOR
LOW
W
1
CAPACITOR
R
Y
BL
BK
8
BLOWER
MOTOR
HIGH
N
BL
N
N