Carrier 48DH - Manual (Page 12)

protective goggles, work gloves and water soaked
quenching cloth.
1. Shut off electrical power and remove all wiring
from compressor.
2. Purge or remove all refrigerant and pressure
from system.
3. Cut suction and discharge lines with tubing
cutter at convenient place near compressor to
f a c i l i t a t e reassembly with copper slip
couplings.
4. Remove compressor from unit and carefully
unbraze piping stubs. Oil vapor in piping stubs
can ignite from torch flame, use quenching
cloth if necessary.
5. Install old piping stubs on new compressor and
carefully braze in place.
6. Clean system. Add or replace liquid line filter
drier.
7. Install new compressor in unit and braze in
place with field-supplied copper slip couplings.
Protect pressure relief plug in suction line with
wet rag if brazing near it.
8. Connect wiling; replace wire terminals if
necessary.
9. Attach caution sticker to new compressor.
10. Proceed with evacuation, charging and start­
up. Procedures for evacuation and system
cleanout can be found in Carrier Standard
Service Techniques Manual, Chapter 1, Form
SM-1.
EVAPORATOR FAN (BLOWER WHEEL) -
Remove fan as follows:
1. Shut off all electrical power to unit.
2. Remove heating section access panel.
3.
On all units except 48DH,DL002, remove
upper right side screw in control box and swing
box downward (Fig. 6).
4. Loosen 5 screws and remove interior panel.
5. Disconnect the 2 wires to the fan motor and
one wire to capacitor.
6. Remove the 2 screws holding the evaporator
fan housing and slide housing and fan from
unit.
COVER (EVAPORATOR HEADER) - To check
for leaks at return bends, it is necessary to remove
cover as follows:
1 Shut off all electrical power to unit.
2. Remove 6 screws holding down condenser fan
grille and orifice.
3. Lift condenser fan grille and orifice and place
on top of unit (Fig. 3). Fan wiring is long
enough for such removal.
4. Remove the top and bottom screws along cover
and remove cover.
Spring Inspection
Disconnect electrical power before working
inside unit
1. Inspect and clean (if required) fan blades and
housing, cooling coil, condensate pan and drain.
See below for cleaning details.
2. Inspect and clean air filter, and supply and
return air grilles.
3. Check electrical components and connections.
Checking procedures may be found in Carrier
Standard Service Techniques Manual, Chapter
2, Form SM-2.
4. Inspect panels and ducts for air leaks.
Fall Inspection
Disconnect electrical power before working
inside unit.
1. Follow all steps under Spring Inspection.
2. Inspect and clean pilot, main burners, heat
exchangers and flues.
3. Check main gas valve operation.
Cleaning
HEAT EXCHANGER
1. Shut down unit.
2. Remove heating section access panel, heat
shield front upper panel, flue box and radiation
baffle over burners. Preserve all gaskets.
3. Clean soot from inside of heat exchanger and
other internal surfaces, especially the narrow
vertical sections of tubes. Use a long wire-
handled
nylon-bristle brush and vacuum
cleaner.
4. Reassemble unit. Take care not to damage
gaskets.
^ INDOOR (EVAPORATOR) COIL ^ Clean with
stiff brush, vacuum cleaner or compressed air.
^ OUTDOOR (CONDENSER) COIL - Clean with
stiff brush, vacuum cleaner, compressed air, or
with low-pressure steam or water. When cleaning
with compressed air, steam or water, guard against
damaging compressor and fan wiring or controls.
CONDENSATE PAN AND DRAIN LINES ~ Clean
once a year, preferably in the spring. Drain off
water in the fall and keep trap dry or protect from
freeze-up thru the winter.
FILTERS — Inspect filters at start of each heating
and cooling season and as often during each season
as conditions warrant. Clean permanent filters per
manufacturer’s
instructions. Throwaway filters
may be cleaned by vacuum or by tapping lightly
over newspaper. Replace filters with the cleaner
side facing downstream. After one cleaning, replace
throwaway filter.
INDOOR FAN ADJUSTMENT - Blower must be
centered in fan housing. To adjust, remove evap­
orator fan housing assembly as described in Part
Removal section. Then loosen setscrew holding
blower to shaft, adjust blower and retighten
setscrew.