Carrier WeatherMaker 38YDB Installation Instructions Manual page 21

C31
R61
R65
S1
120
30
1 2
60
90
0
Y2
Y1
W1
C
R
FAILED COMPONENT
Ambient Thermistor
Outdoor Coil Thermistor
Table 11—Two-Speed Compressor
(Winding Resistance at 70°F ± 20°)
WINDING 2 TON
Start (S-C) 2.280
Run (R-C) 0.770
Compressor Control Contactors
Low and High capacity contactor coils are 24 volts. The electronic
control board controls the operation of the low speed (C-L) and the
high speed (C-H) contactors.
TEMPERATURE THERMISTORS
Thermistors are electronic devices which sense temperature. As
the temperature increases, the resistance decreases. Thermistors
are used to sense outdoor ambient and coil temperature. Refer to
Fig. 16 for resistance values versus temperature.
If the outdoor ambient thermistor or coil thermistor should fail, a
fault code appears at electronic control. The crankcase heater is
turned on during all off cycles.
CEBD430439-03A
SS0ID
R38
R33 R9
J1
DEFROST
TIME (MIN)
R39
R44
R42
60
C18
C16
30
R36
C O M M S TAT U S
D52
D51
A B C
Fig. 15—Control Board
Table 10—Factory Defaults
FUNCTION
Defrost Initiation
One minute fan off dealy in cooling
greater than or equal to 100°F
Defrost Initiation and Termination
3 TON 4 TON 5 TON
1.850 1.459 0.740
0.745 0.552 0.356
C2
PL1
CEPL130439-01
K1
R89
R85
R91
R86 R87
C E S O 1 3 0 0 7 8 - 0 0
D
IMPORTANT: OUTDOOR AIR THERMISTOR PLACEMENT
Mount outdoor air thermistor underneath unit base pan lip on
control box side of unit as shown in Fig. 17. Attach to base pan
with adhesive tape or other field expedient means.
IMPORTANT: If outdoor air thermistor is not properly placed
underneath base pan, unit may have nuisance thermistor out of
range faults.
Step 14—Final Checks
IMPORTANT: Before leaving job, be sure to do the following:
1. Ensure that all wiring and tubing is secure in unit before
adding panels and covers. Securely fasten all panels and
covers.
2. Tighten service valve stem caps to 1/12-turn past finger tight.
3. Leave User's Manual with owner. Explain system operation
and periodic maintenance requirements outlined in manual.
4. Fill out Dealer Installation Checklist and place in customer
file.
21
1
PL2
PL3
1
PL4
1
PL5
PWM2
PWM1
BRN
BLU
BLK
YEL
RED
DEFAULT
Defrost is initiated based on coil
temperature and time.
No delay function
Defrost occurs at each time interval, but
terminate after 5 minutes
A00379