Carrier 48/50PD05 User Manual page 36

LED
FLASH DESCRIPTION
CODE
On Normal Operation
Off Hardware Failure
1 Flash Indoor Fan On/Off Delay
Modified
2 Flashes Limit Switch Fault
3 Flashes Flame Sense Fault
4 Flashes Four Consecutive Limit Switch
Fault
5 Flashes Ignition Fault
6 Flashes Induced Draft Motor Fault
7 Flashes Rollout Switch Lockout
8 Flashes Internal Control Lockout
9 Flashes Temporary Software 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.
PROBLEM
Heat Will Not Turn On.
Inadequate Heating.
Heat Will Not Turn Off.
LEGEND
SAT
- - Supply Air Temperature
Table 13 — IGC Board LED Alarm Codes
ACTION TAKEN BY
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.
Table 14 — Electric Heat Service Analysis
CAUSE
Unit is not configured for heat.
Active alarm.
No power to unit.
Unit is in minimum heat off--- time, or minimum
cool--- heat changeover time.
Heat forced off in Service Test.
No 24 vac at heater contactor.
Open temperature limit switch on heater.
Dirty air filters.
Bad heater elements.
Occupancy schedule set point set too low.
Heat undersized for load.
Restricted or low airflow.
Too much outdoor air.
Limit switch cycles heaters.
Unit is in minimum heat on --- time.
Occupancy schedule set point still calling for
Heating.
Unit running in Service Test mode.
Heater contactor failed.
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.
Power reset. High temperature limit switch opens during heat
exchanger warm-up period before fan-on delay
expires.
High temperature limit switch opens within
10 minutes of heat call (W) Off.
See Limit Switch Fault.
Limit switch closed, or High temperature limit switch is open. Check the
heat call (W) Off. operation of the indoor (evaporator) fan motor.
Ensure that the supply-air temperature rise is within
the range on the unit nameplate. Check wiring and
limit switch operation.
Flame sense normal. The IGC sensed a flame when the gas valve should
Power reset for LED reset. be closed. Check wiring, flame sensor, and gas
valve operation.
Heat call (W) Off. 4 consecutive limit switch faults within a single call
Power reset for LED reset. for heat. See Limit Switch Fault.
Heat call (W) Off. Unit unsuccessfully attempted ignition for 15 minutes.
Power reset for LED reset. Check igniter and flame sensor electrode spacing,
gaps, etc. Check flame sense and igniter wiring.
Check gas valve operation and gas supply.
Inducer sense normal, or Inducer sense On when heat call Off, or inducer
heat call (W) Off. sense Off when heat call On. Check wiring, voltage,
and operation of IGC motor. Check speed sensor
wiring to IGC.
Power reset. Rollout switch has opened. Check gas valve
operation. Check induced-draft blower wheel is
properly secured to motor shaft.
Power reset. IGC has sensed internal hardware or software error.
If fault is not cleared by resetting 24 v power,
replace the IGC.
1 hour auto reset, or Electrical interference is disrupting the IGC
power reset. software.
Check heating configurations using ComfortLinkt
Scrolling Marquee.
Check active alarms using ComfortLink™ Scrolling
Marquee.
Check power supply, fuses, wiring, and circuit breakers.
Check using ComfortLinkt Scrolling Marquee.
Check using ComfortLinkt Scrolling Marquee. Turn
Service Test mode off.
Check transformer, circuit breaker, auto--- reset limit
switches on heater, and manual--- reset limit switches (LS)
on indoor fan housing.
Check minimum airflow. Check limit switch when it is cool,
replace if not.
Replace air filters.
Power off unit and remove high voltage wires. Check
resistance of element, replace if open.
Check setpoints and adjust if necessary.
Decrease load or increase size of heater.
Remove restriction, verify proper fan speed operation, and
check SAT compared to the SAT heating limits.
Check economizer position and configuration. Adjust
minimum position if needed using ComfortLinkt Scrolling
Marquee. Verify proper fan speed operation.
Check rotation of blower, temperature rise of unit, and
minimum airflow. Adjust as needed.
Check using ComfortLinkt Scrolling Marquee.
Check using ComfortLinkt Scrolling Marquee.
Check using ComfortLinkt Scrolling Marquee.
Power off unit. Check contactor and replace if closed.
36
PROBABLE CAUSE
—
REMEDY