Whirlpool WED99HEDC0, Техническое образование

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6-10
n
HybridCare™ Dryer with Heat Pump Technology
TESTING
For Service Technician Use Only
DANGER
Electrical Shock Hazard
Only authorized technicians should perform
diagnostic voltage measurements.
After performing voltage measurements,
disconnect power before servicing.
Failure to follow these instructions can result in
death or electrical shock.
TEST #4: Heating System
This test is performed when either of the following situations
occurs:
ü
Dryer does not heat
ü
Heater will not shut off
This test checks the components making up the heating circuit.
The following items are part of this system:
Part of Heater System Electric Dryer
Harness/connection
ü
Heater relay
ü
Heater element assembly
ü
Compressor relay
ü
Heat pump assembly
ü
Outlet thermistor
ü
Compressor thermistor
ü
Centrifugal switch
ü
High Limit Thermostat
ü
Machine control electronics
ü
TEST #4a: Heater Element
Heater does not heat:
ü Quick Check: Perform steps under “Install Diagnostics”,
page 5-4, to test for L1 and L2 line voltage.
1. Unplug dryer or disconnect power.
2. Remove top panel to access the machine electronics.
3. Remove rear panel to access heater assembly and high
limit thermostat.
4. Check Heater—on the CCU, use an ohmmeter to measure
the resistance at the violet wire terminal on the heater
relay.
¾ If the resistance is ≤ 50 Ω, go to step 6.
¾
If an open circuit is detected, go to step 5.
5. Visually check the wire connection between the relay
and the heater. If the connection looks good, check for
continuity across heater (violet wire to center red wire).
Refer to strip circuit on this page.
¾
Replace the heater if it is electrically open.
6. Check High Limit Thermostat—visually check the wire
connections from the heater and centrifugal switch to the
high limit thermostat. If the connections look good, check
for continuity across the high limit thermostat.
¾
Replace the high limit thermostat if it is electrically
open.
7. If no open circuit is detected, remove the P14 connector
from the CCU and measure the outlet thermistor
resistance between P14-3 and P14-6 at the connector.
Refer to “Outlet Thermistor Resistance” table on page
6-14 for temperatures and their associated values.
¾
If the resistance corresponds to the temperature, the
outlet thermistor is good. Go to step 8.
¾ If the thermistor resistance does not agree with the
table, replace the outlet thermistor.
8. If the preceding steps did not correct the problem and L1
and L2 were both detected, replace the CCU. If L2 was not
detected, inspect the centrifugal switch before replacing
the CCU.
9. Reassemble all parts and panels.
10. Plug in dryer or reconnect power.
11. Perform steps under “Install Diagnostics”, page 5-4, to
verify repair.
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
HEATER STRIP CIRCUIT