Carrier 48N - Manual (Page 19)

(3.) Work cable in and out of cell three or four times
to obtain sufficient cleaning. Do not pull cable
with great force. Reverse drill and gradually
work cable out.
(4.) Remove burner assembly.
(5.) Insert brush end of cable in lower opening of
cell, and proceed to clean in same manner.
(6.) Repeat foregoing procedures until each ceU in
unit has been cleaned.
(7.) Using vacuum cleaner, remove residue from
each cell.
(8.) Using vacuum cleaner with soft brush attach­
ment, clean burner assembly.
(9.) Reinstall burner assembly.
8. After cleaning, check sealant and gaskets to ensure
that they have not been damaged. If new sealants or
gaskets are needed, contact your Distributor.
9. Reinstall flue choke. Be sure all screws are in and tight.
10. Clean and replace flue collector assembly, making sure
all screws are secure.
11. Replace inducer assembly.
12. Recoimect two wires to inducer motor.
13. Replace burner access door.
14. Turn on power and gas.
15. Set thermostat and check unit for proper operation.
E. Pilot
Inspect the pilot and clean (when necessary) at the begin­
ning of each heating season. Remove the accumulation of
soot and carbon from the pilot. The pilot flame must be high
enough for proper impingement on the flame sensor. Pilot
flame must also come in contact with the pilot hood (target)
for proper operation. If the pilot flame appears too hard (lift­
ing and blowing) or too soft (unstable) check inlet gas pres­
sure for proper value. See Table 8. The spark electrode must
be located so the spark travels through a combustible mix­
ture of gas, if necessary, readjust the electrode as shown in
Fig. 11 be certain to maintain the 1/8-in. spark gap.
F. Condenser Coil, Evaporator Coil, and Condensate
Drain Pan
Inspect the condenser coil, evaporator coil, and condensate
drain pan at least once each year. Proper inspection and
cleaning requires the removal of the unit top. See part B of
this section.
The coils are easily cleaned when dry; therefore, inspect and
clean the coils either before or after each cooling season.
Remove all obstructions, including weeds and shrubs that
interfere with the airflow, through the condenser coil.
Straighten bent fins with a fin comb. If coated with dirt or
Hnt, clean the coils with a vacuum cleaner, using the soft
brush attachment. Be careful not to bend the fins. If coated
with oil or grease, clean the coUs with a rtuld detergent-and-
water solution. Rinse coils with clear water, using a garden
hose. Be careful not to splash water on motors, insulation,
wiring, or air filter(s). For best results, spray condenser coU
fins from inside to outside the unit. On units with an outer
and inner condenser coU, be sure to clean between the coils.
Be sure to flush all dirt and debris from the unit base.
Inspect the drain pan and condensate drain line when
inspecting the coils. Clean the drain pan and condensate
drain by removing all foreign matter from the pan. Flush
the pan and drain tube with clear water. Do not splash
water on the insulation, motor, wiring, or air fiilter(s). If the
drain tube is restricted, cleeur it with a “plumbers snake” or
similar probe device.
G. Condenser Fan
A CAUTION
Keep the condenser fan free from all obstructions to
ensure proper cooling operation. Never place articles on
top of the unit. Damage to unit may result.
Remove control and compressor access panels. Inspect the
fan blades for cracks or bends each year. Ensure that blades
clear the motor by no more than 1/4-in. If the blade assembly
has slipped down the motor shaft, adjust the fan position on
the motor shaft by loosening the setscrew(s), then moving
the blade assembly up. Be sure that the setscrew(s) is on the
flat(s) of the motor shaft before tightening.
H. Electrical Controls and Wiring
Inspect and check the electrical controls emd wiring annu­
ally. Be sure to turn off the gas supply and then the electri­
cal power to the unit.
Remove the control, blower, and compressor compartment
access panels to locate all the electrical controls and wiring.
Check all electrical connections for tightness. Tighten all
screw connections. If any smoky or burned connections are
noticed: disassemble the connection, clean aU the parts,
restrip the wire end, and reassemble the connection properly
and securely.
After inspecting the electrical controls and wiring, replace
all the panels. Start the unit, and observe at least one com­
plete heating cycle and one complete cooling cycle to ensure
proper operation. If discrepancies are observed in either or
both operating cycles, or if a suspected malfunction has
Fig. 11—Position of Electrode to Pilot
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