Carrier 48TC 17 Series Service And Maintenance Instructions page 43

WARNING
!
PERSONAL INJURY HAZARD
Failure to follow this WARNING can result in
personal injury.
Disconnect all electrical power when servicing the fan
motor. Apply appropriate lockout/tagout procedures.
3. Shut off power to the unit and install a lockout tag..
4. Disconnect the gas piping at the unit gas valve.
5. Remove the wires connected to the gas valve. Mark
each wire to assist in reconnecting power to the gas
valve.
6. Remove the igniter wires and sensor wires at the Inte-
grated Gas Unit Controller (IGC). See Fig. 55.
7. Remove the 2 screws that attach the burner rack to
the vestibule plate. See Fig. 53.
SCREWS
BURNER
ASSEMBLY
MANIFOLD
PRESSURE TAP
Fig. 53 − Burner Assembly Removal
Item No. Description
1 Gas manifold mounting screws (qty 2)
2 Gas valve inlet plug
3 Propane conversion label
(apply label where indicated)
4 Gas manifold pressure tap
Fig. 54 − Burner Tray Details
VESTIBULE
PLATE
GAS VALVE
C12594
C09395
43
8. Slide the burner tray out of the unit (Fig. 54).
9. To reinstall, reverse the procedure outlined above.
Cleaning and Adjustment
1. Remove the burner rack from the unit as described in
the Removal and Replacement of Gas Train section.
2. Inspect the burners; if dirty, remove the burners from
rack. (Mark each burner to identify its position before
removing from the rack.)
3. Use a soft brush to clean the burners and cross−over
port as required.
4. Adjust the spark gap. The gap should be 0.12 – 0.14"
(3.06 – 3.60 mm) and spaced 0.18" (4.60 mm) from
the end of the burner. (See Fig. 57)
5. If the factory orifice has been removed, check that
each orifice is tight at its threads into the manifold
pipe and the orifice projection does not exceed the
maximum valve. See Fig. 52.
6. Reinstall burners on rack in the same locations as
they were installed at the factory. The outside cross-
over flame regions of the outermost 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 the burner rack as described in the Removal
and Replacement of Gas Train section.