Burner Ignition — Unit is equipped with a direct spark ignition 100% lockout system. Integrated Gas Unit Controller (IGC) is located in the control box (Fig. 10). A single LED on the IGC provides a visual display of operational or sequential problems when the power supply is uninterrupted. The LED can be observed through the viewport. When a break in power occurs, the IGC will be reset (resulting in a loss of fault history) and the evaporator fan on/off times delay will be reset. During servicing, refer to the label on the control box cover or Table 29 for an explanation of LED error code descriptions.
If lockout occurs, unit may be reset by interrupting power supply to unit for at least 5 seconds.
Table 29 — LED Error Code Description*
LED INDICATION | ERROR CODE DESCRIPTION |
ON | Normal Operation |
OFF | Hardware Failure |
1 Flash† | Evaporator Fan On/Off Delay Modified |
2 Flashes | Limit Switch Fault |
3 Flashes | Flame Sense Fault |
4 Flashes | 4 Consecutive Limit Switch Faults |
5 Flashes | Ignition Lockout Fault |
6 Flashes | |
7 Flashes | Rollout Switch Fault |
8 Flashes | Internal Control Fault |
LEGEND |
|
LED —
*A
†Indicates a code that is not an error. The unit will continue to oper- ate when this code is displayed.
IMPORTANT: Refer to Troubleshooting Tables
Main Burners — At the beginning of each heating sea- son, inspect for deterioration or blockage due to corrosion or other causes. Observe the main burner flames and adjust, if necessary.
When servicing gas train, do not hit or plug orifice spuds.
REMOVAL AND REPLACEMENT OF GAS TRAIN (See Fig. 52 and 53)
1.Shut off manual gas valve.
2.Shut off power to unit, tag disconnect.
3.Remove compressor access panel.
4.Slide out burner compartment side panel.
5.Disconnect gas piping at unit gas valve.
6.Remove wires connected to gas valve. Mark each wire.
7.Remove
8.Remove the 2 screws that attach the burner rack to the vestibule plate.
9.Remove the gas valve bracket.
10.Slide the burner tray out of the unit (Fig. 53).
11.To reinstall, reverse the procedure outlined above.
INDUCED- | ROLLOUT |
DRAFT | SWITCH |
MOTOR |
|
MOUNTING |
|
PLATE |
|
BURNER |
|
SECTION | FLUE |
| EXHAUST |
| VESTIBULE |
INDUCED- | PLATE |
DRAFT | BLOWER |
MOTOR | |
| HOUSING |
MANIFOLD | GAS |
PRESSURE | |
TAP | VALVE |
Fig. 52 — Burner Section Details
Fig. 53 — Burner Tray Details
CLEANING AND ADJUSTMENT
1.Remove burner rack from unit as described above.
2.Inspect burners and, if dirty, remove burners from rack.
3.Using a soft brush, clean burners and
4.Adjust spark gap. See Fig. 54.
5.Reinstall burners on rack.
6.Reinstall burner rack as described above.
Replacement Parts — A complete list of replace- ment parts may be obtained from any Carrier distributor upon request. Refer to Fig. 55 for a typical unit wiring schematic.
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