43
Limit Switch
Remove blower access panel. Limit switch is located on
the fan deck for sideshot units and on the vestibule plate
for downshot units. See Fig. 50.
48HC*D08 only
C09396
All 48HC*D except *D08
C08238A
LP LOW PRESSURE
SWITCH
GAS VALVE
Fig. 51 -- LP Low Pressure Switch (Installed)
PNK
W2
TSTAT
GRA
BRN
IGC
J2-12
IGC
J2-11
BRN
C
NO
MGV
C
LP LPS
C08285
Fig. 52 -- LP Supply Line Low Pressure Switch Wiring
This switch also prevents operation when the propane tank
level is low which can result in gas with a high
concentration of impurities, additives, and residues that
have settled to the bottom of the tank. Operation under
these conditions can cause harm to the heat exchanger
system. Contact your fuel supplier if this condition is
suspected.
Flue Gas Passageways
To inspect the flue collector box and upper areas of the
heat exchanger:
1. Remove the combustion blower wheel and motor as-
sembly according to directions in Combustion--Air
Blower section. See Fig. 53.
2. Remove the flue cover to inspect the heat exchanger.
3. Clean all surfaces as required using a wire brush.
Combustion--Air Blower
Clean periodically to assure proper airflow and heating
efficiency. Inspect blower wheel every fall and
periodically during heating season. For the first heating
season, inspect blower wheel bi--monthly to determine
proper cleaning frequency.
To access burner section, open the heater access door
below the indoor fan panel.
To inspect blower wheel, shine a flashlight into draft hood
opening. If cleaning is required, remove motor and wheel
as follows:
1. Remove the seven screws attaching the induced--draft
motor housing to the vestibule plate. See Fig. 53.
2. The blower wheel can be cleaned at this point. If ad-
ditional cleaning is required, continue with Steps 3
through 5.
3. Remove the blower from the motor shaft, by
loosening two setscrews.
4. Remove the motor by removing the four screws that
hold the motor to mounting plate. Remove the motor
cooling fan by removing one setscrew.
5. Remove the nuts that hold the motor to the mounting
plate.
6. To reinstall, reverse the procedure outlined above.
48H
C
Summary of Contents for 48HC D17 Series
Page 77: ...77 APPENDIX IV WIRING DIAGRAMS C12616 Fig 77 48HC D17 D28 Power Diagram 208 230 3 60 48HC...
Page 78: ...78 APPENDIX IV WIRING DIAGRAMS C12617 Fig 78 48HC D17 D28 Power Diagram 460 3 60 48HC...
Page 79: ...79 APPENDIX IV WIRING DIAGRAMS C12618 Fig 79 48HC D17 D28 Power Diagram 575 3 60 48HC...
Page 86: ...86 APPENDIX IV WIRING DIAGRAMS C13767 Fig 86 RTU OPEN Wiring Diagram 48HC...
Page 87: ...87 APPENDIX IV WIRING DIAGRAMS C13768 Fig 87 RTU OPEN Wiring Diagram with Humidi MiZer 48HC...
