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6. Disconnect gas piping at unit gas valve.
7. Remove wires connected to gas valve. Mark each wire.
8. Remove igniter wires and sensor wires at the Integrated
Gas Unit Controller (IGC). (See Fig. 54.)
9. Remove the two screws attaching the burner rack to the
vestibule plate (see Fig. 50).
10. Slide the burner tray out of the unit (see Fig. 53).
11. Reverse the procedures outlined above to reinstall the
burner rack.
CLEANING AND ADJUSTMENT
1. Remove burner rack from unit as described in “Removal
and Replacement of Gas Train” section.
2. Inspect burners; if dirty, remove burners from rack. (Mark
each burner to identify its position before removing from
the rack.)
3. Use a soft brush to clean burners and cross-over port as
required.
4. Adjust spark gap. (See Fig. 55-58.)
5. If factory orifice has been removed, check that each orifice
is tight at its threads into the manifold pipe and that orifice
projection does not exceed maximum valve. See Fig. 52.
6. Reinstall burners on rack in the same locations as factory-
installed. (The outside crossover flame regions of the out-
ermost burners are pinched off to prevent excessive gas
flow from the side of the burner assembly. If the pinched
crossovers are installed between two burners, the flame
will not ignite properly.)
7. Reinstall burner rack as described in “Removal and
Replacement of Gas Train” section.
Fig. 53 — Burner Tray Details
Fig. 54 — Unit Control Box/IGC Location
Removing the Heat Exchanger
The following procedure details the steps to remove the heat ex-
changed from the unit.
1. Turn off electric power to the unit and shut off the unit’s
gas supply.
2. Remove the two exterior panels: control box access panel
and indoor blower access panel.
3. Remove the unit center post (see Fig. 51).
4. Remove the three interior panels: control box high voltage
panel, burner partition panel, and heat exchanger cover panel.
5. Disconnect the wires connected to the gas valve. Mark
each wire.
6. Disconnect the igniter wires and sensor wires at the inte-
grated gas controller (IGC).
7. Disconnect a gas pipe union and remove the gas manifold
with the gas valve.
8. Remove the two screws attaching the burner rack to the
vestibule plate (see Fig. 50).
9. Remove the pressure switch hose from the connection on
the flue cover assembly (see Fig. 50).
10. Remove the screws around the vestibule plate.
11. Remove the nuts holding the heat exchanger support rack
to the fan deck.
12. Remove the heat exchanger from the unit.
13. Separate the following from the heat exchanger: inducer
fan-motor assembly, flue cover assembly, retainer, regula-
tor, regulator gasket, and if a Low NOx unit, also remove
the baffle assembly. See Fig. 50.
RACEWAY
INTEGRATED GA
S
UNIT
CONTROLLER (IGC)
HOLE IN END PANEL (HIDDEN)
Summary of Contents for WeatherMaster 48HC04 Series
Page 37: ...37 Fig 60 Integrated Gas Control IGC Board RED LED STATUS ...
Page 45: ...45 Fig 65 RTU Open Overlay for Economizer Wiring ...
Page 46: ...46 Fig 66 VFD Overlay for W2770 Controller Wiring ...
Page 98: ...98 Fig E 48HC A07 YAC Control Diagram 208 230 3 60 460 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 100: ...100 Fig G 48HC D11YAC Control Diagram 208 230 3 60 460 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 101: ...101 Fig H 48HC D12 YAC Control Diagram 208 230 3 60 460 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 102: ...102 Fig I 48HC A04 A06 YAC Power Diagram 208 230 1 60 APPENDIX D WIRING DIAGRAMS ...
Page 103: ...103 Fig J 48HC A04 A06 YAC Power Diagram 208 230 3 60 460 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 104: ...104 Fig K 48HC A04 A06 YAC Power Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 107: ...107 Fig N 48HC A07 A12 YAC Power Diagram 208 230 3 60 460 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 108: ...108 Fig O 48HC A07 A12 YAC Power Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 109: ...109 Fig P 48HC D08 D09 YAC Power Diagram 230 460 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 110: ...110 Fig Q 48HC D08 D09 YAC Power Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 111: ...111 Fig R 48HC D11 YAC Power Diagram 208 230 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 112: ...112 Fig S 48HC D11 YAC Power Diagram 460 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 113: ...113 Fig T 48HC D11 YAC Power Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 114: ...114 Fig U 48HC D12 YAC Power Diagram 230 460 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 115: ...115 Fig V 48HC D12 YAC Power Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 116: ...116 Fig W 48HC D14 YAC Control Diagram 208 230 3 60 460 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 117: ...117 Fig X 48HC D14 YAC Power Diagram 208 230 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 118: ...118 Fig Y 48HC D14 YAC Power Diagram 460 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 119: ...119 Fig Z 48HC D14 YAC Power Diagram 575 3 60 APPENDIX D WIRING DIAGRAMS ...
Page 142: ...142 Fig AW PremierLink System Control Wiring Diagram System APPENDIX D WIRING DIAGRAMS ...
Page 144: ...144 Fig AY RTU Open Wiring Diagram APPENDIX D WIRING DIAGRAMS ...