Carrier FA4ANF, Руководство по обслуживанию, Страница: 35 / 52

+ CIRCUIT BOARD
- Check 5-amp fuse.
- Check for 24v between SEC1 and SEC2. If no voltage is
present, check the transformer.
- Check for burn traces or burnt components. If burn spots are
present, replace board.
+ ROOM THERMOSTAT
- Remove thermostat wires from the circuit board.
- Jumper screw terminals (1 at a time) R-G, R-Y/Y2, R-Y1,
and R-W1. If motor runs in all cases, thermostat is bad. Replace
thermostat. If motor does not run, or runs in some cases but not in
others, continue by checking the wiring harness.
+ WIRING HARNESS
- Shut off power to unit.
- Remove 5-pin plug from motor.
Never remove 5-pin high voltage plug from the motor with
the power on.
- Remove 16-pin plug from motor.
- Replace 5-pin plug and turn on power.
- Check for 24v between pin-1 and pin-12 on the 16-pin plug.
(See Fig. 27.) If no voltage is present, replace wiring harness. If
voltage is present, jumper screw terminal R-Y/Y2 on circuit board
and check for 24v between pin-1 and pin-14 on 16-pin plug. (See
Fig. 27.) If voltage is present, check harness connections G, Y1,
W1, W2.
- If 24v is not present, the harness is bad. Replace harness.
G — Pin 15
Y1 — Pin 6
W1 — Pin 2
W1 — Pin 13
Step 16—Accessories
ELECTRONIC AIR CLEANER (EAC)
230-vac EAC control/power signal EAC1 and EAC2 is not
available, because the ICM2 blower motor used in the FK4C,
FV4A, and 40FKA Fan Coils is controlled by low-voltage signals.
This signal is replaced by a 24-vac signal which is provided at
circuit board terminals AUX1 and AUX2. (See Fig 24.) This signal
is present when either G or W is present and is active in all heating
and cooling modes. User-supplied 110 vac is switched by relay to
power air cleaner when G or W are present. (See Fig. 28.)
FK4C, FV4A, AND 40FKA DE-HUMIDIFY MODE
NOTE: Humidistat must open on humidity rise.
Latent capacities for systems using the FK4C, FV4A, and 40FKA
fan coils are better than average systems. If increased latent
capacity is an application requirement, the field wiring terminal
block provides connection terminals for use of a standard humi-
distat. The FK4C, FV4A, and 40FKA fan coils will detect the
Table 9—FK4C Motor Control Test Values
(With 16-pin connector at motor unplugged)
OPERATING MODE
SCREW TERMINALS
HAVING 24 VAC
** VOLTAGES—12-PIN PLUG PL1
W1
Pin 7
G
Pin 1
C
Pin 9
C
Pin 10
R
Pin 8
Y/Y2
Pin 2
Y1
Pin 3
Electric Heating R W1 W2 24 vac 0 0 0 24 vac 0
1-Speed A/C Cooling R Y/Y2 G 0 24 vac 0 0 24 vac -12 vdc 0
2-Speed A/C, Low Speed Cooling R Y1 G 0 24 vac 0 0 24 vac 0 -12 vdc
2-Speed A/C, High Speed Cooling R Y/Y2 G Y1 0 24 vac 0 0 24 vac -12 vdc -12 vdc
1-Speed HP Cooling R Y/Y2 G O 0 24 vac 0 0 24 vac -12 vdc 0
1-Speed HP Heating R Y/Y2 G 0 24 vac 0 0 24 vac -12 vdc 0
2-Speed HP, Low Speed Cooling R Y1 G O 0 24 vac 0 0 24 vac 0 -12 vdc
2-Speed HP, Low Speed Heating R Y1 G 0 24 vac 0 0 24 vac 0 -12 vdc
2-Speed HP, High Speed Cooling R Y/Y2 Y1 G O 0 24 vac 0 0 24 vac -12 vdc -12 vdc
2-Speed HP, High Speed Heating R Y/Y2 Y1 G 0 24 vac 0 0 24 vac -12 vdc -12 vdc
Continuous Fan Low R G 0 24 vac 0 0 24 vac 0 0
Continuous Fan Medium R G 0 24 vac 0 0 24 vac -12 vdc 0
Continuous Fan High R G 0 24 vac 0 0 24 vac 0 -12 vdc
→
** AC voltages less than 18 are not recognized by the ICM.
Fig. 27—Wiring Harness 16-Pin Plug
A94375
16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1
16-PIN PLUG
→
Fig. 28—KFAIR0201ACR Relay Kit
Wiring Schematic
A98625
24 VAC RELAY
FAN COIL
230 VAC OR
115 VAC BRANCH CKT
AUX1
(C)
AUX2
(G)
GND HOT NEUT
GRN
BLK
WHT
NO
COM
BLK
BLK
RED RED
WHT
TO EAC
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