Table of Contents
Advertisement
OPERATING MODE
Electric
1-Speed A/C
2-Speed A/C, Low Speed
2-Speed A/C, High Speed
1-Speed HP
1-Speed HP
2-Speed HP, Low Speed
2-Speed HP, Low Speed
2-Speed HP, High Speed
2-Speed HP, High Speed
Continuous Fan
* Pin 1 @ 24 vdc with or without jumpers when ever any individual heater input or any combination of heater inputs are energized.
→ ** Voltages less than 18 are not recognized on the ICM.
- If motor does not stop running, remove the 7-pin plug from
circuit board. If motor continues to run, replace motor. If motor
stops running, it is either the circuit board or thermostat causing
the problem. Test whether thermostat is at fault by disconnecting
it from the board.
+ CIRCUIT BOARD
- Check 5-amp fuse.
- Check for 230v between terminals M1 and M2. If no voltage
is present, check power to board. 230-v power enters the board
through the black and yellow lead in the 12-pin plug.
- 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-W2. 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.
CAUTION: 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. 19.) 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-12 and pin-14 on 16-pin plug. (See
Fig. 19.) If voltage is present, replace harness.
- If 24v is present, the motor is bad. Replace motor.
VIII. ACCESSORIES
A. Electronic Air Cleaner (EAC)
Familiar 230-vac EAC control/power signal EAC1 and EAC2 is
not available, because the ICM2 blower motor used in the FK4B
Fan Coil is controlled by low-voltage signals. This signal is
replaced by a 24-vdc signal which is provided at circuit board
terminals AUX1 and AUX2. (See Fig 16.)
This signal is present when either G or W is present and is active
in all heating and cooling modes. Because 24-vdc relays may not
be readily available to installer, a kit exists, KFAIR0101ACR,
containing a 24-vdc relay which mounts directly inside EAC
cabinet. User-supplied 110 vac is switched by relay to power air
cleaner when G or W are present. (See Fig. 20 and 21.)
TABLE 6—FK4B MOTOR CONTROL TEST VALUES
(WITH 16-PIN CONNECTOR AT MOTOR UNPLUGGED)
SCREW TERMINALS
HAVING 24 VAC
Heating
R
W2
W3*
Cooling
R
Y/Y2
G
Cooling
R
Y1
G
Cooling
R
Y/Y2
G
Cooling
R
Y/Y2
G
Heating
R
Y/Y2
G
Cooling
R
Y1
G
Heating
R
Y1
G
Cooling
R
Y/Y2
Y1
Heating
R
Y/Y2
Y1
R
G
** VOLTAGES—7-PIN PLUG P2
W
G
Pin 1
Pin 2
E*
24 vdc
0
0
24 vac
0
24 vac
0
24 vac
O
0
24 vac
0
24 vac
O
0
24 vac
0
24 vac
G
O
0
24 vac
G
0
24 vac
0
24 vac
16
15
8
7
Fig. 19—Wiring Harness 16-Pin Plug
Fig. 20—Mounting KFAIR0101ACR Relay Kit
In heat pump applications, the G signal is present in both cooling
and heating modes, permitting EAC to be controlled from G signal
only. For this application, a user-supplied 24-vac relay can be
driven by G terminal eliminating need for relay kit.
B. FK4B De-Humidify Mode
NOTE: Humidistat must open on humidity rise.
—27—
C
C
R
Y/Y2
Pin 3
Pin 4
Pin 5
Pin 6
0
0
24 vac
0
0
24 vac
24 vac
0
0
24 vac
0
0
24 vac
24 vac
0
0
24 vac
24 vac
0
0
24 vac
24 vac
0
0
24 vac
0
0
24 vac
0
0
24 vac
24 vac
0
0
24 vac
24 vac
0
0
24 vac
14
13
12
11
10
6
5
4
3
2
16-PIN PLUG
MOUNT FLUSH WITH
THESE TWO EDGES
Y
Pin 7
0
0
0
24 vac
0
0
0
0
24 vac
0
24 vac
24 vac
24 vac
0
0
9
1
A94375
A93216
Advertisement
Table of Contents
Troubleshooting
