Whirlpool WED99HEDC0, Technical Education

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TESTING
HybridCare™ Dryer with Heat Pump Technology
n
6-15
For Service Technician Use Only
TEST #5: Moisture Sensor
This test is performed when an automatic cycle stops too
soon, or runs much longer than expected.
NOTE: Dryer will shut down automatically after 4 hours and 10
minutes.
The following items are part of this system:
Part of Moisture System Electric Dryer
Harness/connection
ü
Metal sensor strips
ü
Machine control electronics
ü
NOTE: Refer to strip circuit below to diagnose moisture sensor.
1. Activate the Loads Test mode. See procedures on page 5-3.
2. Open the door. Using a wet cloth or one finger, jointly
touch both sensor strips.
¾
If a repeating beep tone is heard and an alphanumeric
number is displayed on the console, the moisture
sensor passes the test. Go to step 9.
¾
If a beep tone is not heard, or a repeating beep tone is
heard before touching both moisture strips, continue
with step 3.
NOTE: Over-drying may be caused by a short circuit in the
sensor system.
3. Unplug dryer or disconnect power.
4. Remove top panel to access the machine electronics.
5. Access the moisture sensor wires by removing the console
and front panel. Disconnect the 3-wire moisture sensor
connector located below the door opening between the
front panel and bulkhead.
6. Access the CCU and remove connector P13 from the
circuit board. Check the wire harness for continuity
between P13 and the moisture sensor connector.
¾
If there is continuity, go to step 7.
¾
If there is no continuity, replace the main harness.
7. Measure the resistance across the outermost contacts of
the connector that includes the two MOVs.
3$*(
FOR SERVICE TECHNICIAN’S USE ONLY
DO NOT REMOVE OR DESTROY
TEST #5: Moisture Sensor
This test is performed when an automatic
cycle stops too soon, or runs much longer
than expected.
NOTE: Dryer will shut down automatically
after 4 hours and 10 minutes.
The following items are part of this system:
NOTE: Refer to strip circuit on page 20
to diagnose moisture sensor.
1. Activate the Loads Test mode. See
procedures on page 4.
2. Open the door. Using a wet cloth or one
finger, jointly touch both sensor strips.
¾
If a repeating beep tone is heard and an
alphanumeric number is displayed on the
console, the moisture sensor passes the
test. Go to step 9.
¾
If a beep tone is not heard, or a repeating
beep tone is heard before touching both
moisture strips, continue with step 3.
NOTE: Overdrying may be caused by a short
circuit in the sensor system.
3. Unplug dryer or disconnect power.
4. Remove top panel to access the machine
electronics.
5. Access the moisture sensor wires
by removing the console and front panel.
Disconnect the 3-wire moisture sensor
connector located below the door opening
between the front panel and bulkhead.
6. Access the CCU and remove connector
P13 from the circuit board. Check the wire
harness for continuity between P13 and the
moisture sensor connector.
¾
If there is continuity, go to step 7.
¾
If there is no continuity, replace the main
harness.
Part of Moisture System
Electric
Dryer
Harness/connection
ü
Metal sensor strips
ü
Machine control electronics
ü
7. Measure the resistance across the
outermost contacts of the connector that
includes the two MOVs.
¾
If a small resistance is measured, clean the
two metal moisture strips inside the drum.
If a small resistance is measured after
cleaning, replace sensor harness.
¾
If a small resistance is not measured,
go to step 8.
8. Measure the resistance across each of the
outermost contacts and the center terminal
(ground connection).
¾
If a resistance less than infinity is
measured, replace the sensor harness.
9. If the moisture sensor diagnostic test passes,
check the outlet thermistor: TEST #4a, page 15.
¾
If the problem persists after replacing the
moisture sensor and thermistor, consider
adjusting the dryness level (see TEST #5a:
Adjusting Customer-Focused Dryness Level).
10. If the preceding steps did not correct the
problem, replace the CCU.
TEST #5a: Adjusting Customer-
Focused Dryness Level
NOTE: If the customer complains about the
clothes being less dry or more dry than desired
and the moisture sensor passes TEST #5:
Moisture Sensor, step 2, the total dry time can
be lengthened or shortened by changing the
Customer-Focused Dryness Level from “ 1 ”
(standard auto cycle) to a “ 2 ” (15% more drying
time), “ 3 ” (30% more drying time), “ 4 ” (15%
less drying time), or “ 5 ” (30% less drying time)
auto cycle.
1. In standby mode (dryer plugged in but not
powered up), press and hold the DRYNESS
LEVEL button for approximately 3 seconds.
The dryer will beep and “ CF ” is displayed
followed by the current dryness setting on the
7-segment display. The factory default value
is “ 1 ”.
¾
If a small resistance is measured, clean the two metal
moisture strips inside the drum. If a small resistance is
measured after cleaning, replace sensor harness.
¾
If a small resistance is not measured, go to step 8.
8. Measure the resistance across each of the outermost
contacts and the center terminal (ground connection).
3$*(
FOR SERVICE TECHNICIAN’S USE ONLY
DO NOT REMOVE OR DESTROY
TEST #5: Moisture Sensor
This test is performed when an automatic
cycle stops too soon, or runs much longer
than expected.
NOTE: Dryer will shut down automatically
after 4 hours and 10 minutes.
The following items are part of this system:
NOTE: Refer to strip circuit on page 20
to diagnose moisture sensor.
1. Activate the Loads Test mode. See
procedures on page 4.
2. Open the door. Using a wet cloth or one
finger, jointly touch both sensor strips.
¾
If a repeating beep tone is heard and an
alphanumeric number is displayed on the
console, the moisture sensor passes the
test. Go to step 9.
¾
If a beep tone is not heard, or a repeating
beep tone is heard before touching both
moisture strips, continue with step 3.
NOTE: Overdrying may be caused by a short
circuit in the sensor system.
3. Unplug dryer or disconnect power.
4. Remove top panel to access the machine
electronics.
5. Access the moisture sensor wires
by removing the console and front panel.
Disconnect the 3-wire moisture sensor
connector located below the door opening
between the front panel and bulkhead.
6. Access the CCU and remove connector
P13 from the circuit board. Check the wire
harness for continuity between P13 and the
moisture sensor connector.
¾
If there is continuity, go to step 7.
¾
If there is no continuity, replace the main
harness.
Part of Moisture System
Electric
Dryer
Harness/connection
ü
Metal sensor strips
ü
Machine control electronics
ü
7. Measure the resistance across the
outermost contacts of the connector that
includes the two MOVs.
¾
If a small resistance is measured, clean the
two metal moisture strips inside the drum.
If a small resistance is measured after
cleaning, replace sensor harness.
¾
If a small resistance is not measured,
go to step 8.
8. Measure the resistance across each of the
outermost contacts and the center terminal
(ground connection).
¾
If a resistance less than infinity is
measured, replace the sensor harness.
9. If the moisture sensor diagnostic test passes,
check the outlet thermistor: TEST #4a, page 15.
¾
If the problem persists after replacing the
moisture sensor and thermistor, consider
adjusting the dryness level (see TEST #5a:
Adjusting Customer-Focused Dryness Level).
10. If the preceding steps did not correct the
problem, replace the CCU.
TEST #5a: Adjusting Customer-
Focused Dryness Level
NOTE: If the customer complains about the
clothes being less dry or more dry than desired
and the moisture sensor passes TEST #5:
Moisture Sensor, step 2, the total dry time can
be lengthened or shortened by changing the
Customer-Focused Dryness Level from “ 1 ”
(standard auto cycle) to a “ 2 ” (15% more drying
time), “ 3 ” (30% more drying time), “ 4 ” (15%
less drying time), or “ 5 ” (30% less drying time)
auto cycle.
1. In standby mode (dryer plugged in but not
powered up), press and hold the DRYNESS
LEVEL button for approximately 3 seconds.
The dryer will beep and “ CF ” is displayed
followed by the current dryness setting on the
7-segment display. The factory default value
is “ 1 ”.
¾
If a resistance less than infinity is measured, replace
the sensor harness.
9. If the moisture sensor diagnostic test passes, check the
outlet thermistor: TEST #4a, page 6-15.
¾
If the problem persists after replacing the moisture
sensor and thermistor, consider adjusting the dryness
level (see TEST #5a: Adjusting Customer-Focused
Dryness Level).
10. If the preceding steps did not correct the problem, replace
the CCU.
WARNING
Electrical Shock Hazard
Disconnect power before servicing.
Failure to do so can result in death or
electrical shock.
Replace all parts and panels before operating.
3$*(
FOR SERVICE TECHNICIAN’S USE ONLY
DO NOT REMOVE OR DESTROY
STRIP CIRCUITS
MOTOR CIRCUIT
HEATER
THERMISTORS (COMPRESSOR/OUTLET)
MOISTURE SENSOR
L1
BK
P9-1
K1
MOTOR RELAY
CYCLE CONTROL UNIT
LBU LBU
4M
DRIVE MOTOR
1/3 HP
MAIN
START
5M
3M 6M
2M
1M
See Heater Circuit
W
BU
N.O.
DOOR
SWITCH
W
N
P9-2
CENTRIFUGAL
SWITCH
BU
THERMAL
PROTECT
LBU
W
P14-1
COMPRESSOR
THERMISTOR
CYCLE CONTROL UNIT
PK
OUTLET
THERMISTOR
P14-3
10K
Ω
COMPRESSOR TEMP THERMISTOR
OUTLET TEMP THERMISTOR
R-W
10K
Ω
V
COMPRESSOR
THERMISTOR RTN
CYCLE CONTROL UNIT
OUTLET
THERMISTOR RTN
Y
P14-2
P14-6
CYCLE CONTROL UNIT
P13-1
BK
MOISTURE SENSOR
CYCLE CONTROL UNIT
MOISTURE SENSOR RTN
MOISTURE SENSOR
P13-2
P8-2
CHASSIS GND
Y-R
MOV MOV
BK R
G-Y G-Y
G-Y
CHASSIS GND
Figure 8 - Strip circuits.
5M
3M 6M
2M
1M
CENTRIFUGAL SWITCH
See
Motor
Circuit
HEATER
R
R
V
V
V
L2
R
HIGH LIMIT
THERMOSTAT
L1
BK
RELAY K3
CYCLE CONTROL UNIT
N.O. COM1
MOTOR SENSOR STRIP CIRCUIT