Carrier WeatherMaster 48HC Series Installation Instructions Manual page 27

Table 7 — IGC Board Faults
LED INDICATION
ON
OFF
1 Flash
2 Flashes
3 Flashes
4 Flashes
5 Flashes
6 Flashes
7 Flashes
8 Flashes
NOTE: If more than one error mode exists, they will be displayed on the
LED in sequence. Limit switch is ignored in all modes except heating
mode.
LED FLASH
CODE
On Normal Operation
Off Hardware Failure
Indoor Fan On/Off Delay
1 Flash
Modified
2 Flashes Limit Switch Fault
3 Flashes Flame Sense Fault
Four Consecutive Limit
4 Flashes
Switch Fault
5 Flashes Ignition Fault
6 Flashes Induced Draft Motor Fault
7 Flashes Rollout Switch Lockout
8 Flashes Internal Control Lockout
Temporary Software
9 Flashes
Lockout
LEGEND
IGC — Integrated Gas Unit Control
LED — Light-Emitting Diode
NOTES:
1. There is a 3-second pause between alarm code displays.
2. If more than one alarm code exists, all applicable alarm codes will
be displayed in numerical sequence.
3. Alarm codes on the IGC will be lost if power to the unit is interrupted.
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ERROR MODE
Normal operation
No power or hardware failure
Fan on delay modified
Limit switch fault
Flame sense fault
Consecutive limit switch faults
Ignition lockout fault
Pressure switch fault
Rollout switch fault
Internal control fault
Table 8 — IGC Board LED Alarm Codes
ACTION TAKEN BY
DESCRIPTION
CONTROL
—
No gas heating.
5 seconds subtracted from
On delay. 5 seconds
added to Off delay (3 min
max).
Gas valve and igniter Off.
Indoor fan and inducer On.
Indoor fan and inducer On.
No gas heating.
No gas heating.
If heat off: no gas heating.
If heat on: gas valve Off
and inducer On.
Gas valve and igniter Off.
Indoor fan and inducer On.
No gas heating.
No gas heating.
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COMFORTLINK (FACTORY OPTION)
For details on operating 48HC units equipped with the factory in-
stalled ComfortLink option, refer to "Controls, Start-Up, Opera-
tion and Troubleshooting for 48/50HC 04-28 Single Package
Rooftop Unit with ComfortLink Controls." See Fig. 51-55 for wir-
ing details.
TYPICAL WIRING DIAGRAMS
See Fig. 56-63 for typical wiring diagrams.
RESET METHOD
— —
Loss of power to the IGC. Check 5 amp fuse on
— IGC, power to unit, 24V circuit breaker,
transformer, and wiring to the IGC.
High temperature limit switch opens during heat
exchanger warm-up period before fan-on delay
Power reset. expires. High temperature limit switch opens
within 10 minutes of heat call (W) Off. See Limit
Switch Fault.
High temperature limit switch is open. Check the
operation of the indoor (evaporator) fan motor.
Limit switch closed, or heat
Ensure that the supply-air temperature rise is
call (W) Off.
within the range on the unit nameplate. Check
wiring and limit switch operation.
The IGC sensed a flame when the gas valve
Flame sense normal.
should be closed. Check wiring, flame sensor,
Power reset for LED reset.
and gas valve operation.
Heat call (W) Off. Power 4 consecutive limit switch faults within a single
reset for LED reset. call for heat. See Limit Switch Fault.
Unit unsuccessfully attempted ignition for 15
minutes. Check igniter and flame sensor
Heat call (W) Off. Power
electrode spacing, gaps, etc. Check flame sense
reset for LED reset.
and igniter wiring. Check gas valve operation and
gas supply.
Inducer sense On when heat call Off, or inducer
Inducer sense normal, or sense Off when heat call On. Check wiring,
heat call (W) Off. voltage, and operation of IGC motor. Check
speed sensor wiring to IGC.
Rollout switch has opened. Check gas valve
Power reset. operation. Check induced-draft blower wheel is
properly secured to motor shaft.
IGC has sensed internal hardware or software
Power reset. error. If fault is not cleared by resetting 24 v
power, replace the IGC.
1 hour auto reset, or power Electrical interference is disrupting the IGC
reset. software.
27
PROBABLE CAUSE