Burners And Igniters - Carrier 48JCH 04-06 Series Service And Maintenance Instructions

Burners and Igniters

CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this CAUTION can result in premature wear
and damage to equipment.
When working on gas train, do not hit or plug orifice spuds.
BURNERS BOX/HEAT EXCHANGER ASSEMBLY
The main burners are not accessible on any Ultra Low NOx
units (low heat/medium heat). No serviceable parts. Replace
with new burner box/heat exchanger assembly. This assembly
is a single unit and if replacement is required, the entire
assembly must be replaced.
Orifice Projection and Placement
Refer to Fig. 44 for maximum projection and placement
dimension for orifice face to manifold tube. The manifold,
orifice and intake shall be concentric. The orifice must be
centered in the intake tube.
Intake Orifice
Orifice must be
centered in tube
within 0.05 in.
Fig. 44 — Orifice Projection
REMOVAL AND REPLACEMENT OF GAS TRAIN
See Fig. 41, 43, 46, and 45.
1. Shut off manual gas valve.
2. Shut off power to unit.
3. Remove the control box access panel.
4. Remove the control box high voltage cover.
5. Remove the screw at the base of the burner partition panel
and slide out the panel (see Fig. 46).
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. 45).
9. Remove the six screws attaching the gas valve assembly to
the burner box assembly (see Fig. 43).
10. Reverse the procedures outlined above to reinstall the gas
valve assembly.
Manifold Pressure Tap
Manifold
Manifold, orifice and intake shall
be concentric. The orifice location
verified with respect to the intake.
CLEANING AND ADJUSTMENT
1. Remove gas valve assembly from unit as described in
"Removal and Replacement of Gas Train" on page 26.
2. If factory orifice has been removed, check that each orifice is
tight at its threads into the manifold pipe, and that orifice pro-
jection does not exceed maximum value (see Fig. 44).
3. Reinstall gas valve assembly as described in "Removal and
Replacement of Gas Train" on page 26.
4. Remove igniter modules from the top of the burner box
assembly. Inspect and adjust the spark gap, if necessary
(see Fig. 47).
Fig. 45 — 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. 46).
4. Disconnect the two wires from the gas limit switch.
5. Remove the three interior panels: control box high voltage
panel, burner partition panel, and heat exchanger cover panel.
6. Disconnect the wires connected to the gas valve. Mark
each wire.
7. Disconnect the igniter wires and sensor wires at the integrated
gas controller (IGC).
8. Disconnect a gas pipe union and remove the gas manifold
with the gas valve.
9. Remove the six screws attaching the gas valve assembly to
the burner box assembly (see Fig. 43).
10. Remove the pressure switch hose from the connection on the
flue cover assembly (see Fig. 43).
11. Remove the screws around the vestibule plate.
12. Remove the nuts holding the heat exchanger support rack to
the fan deck.
13. Remove the heat exchanger from the unit.
26
Integrated Gas
Controller (IGC)