Heat Anticipator Setting; Transformer Protection; Pre- -Start- -Up; Check For Refrigerant Leaks - Carrier 48SD Installation Instructions Manual

Run the low- -voltage leads from the thermostat, through the inlet
hole, and into unit low- -voltage splice box (see Fig. 13).
Locate five 18- -gage wires leaving control box. These low- -voltage
connection leads can be identified by the colors red, green, yellow,
brown, and white (See Fig. 11). Ensure the leads are long enough
to be routed into the low- -voltage splice box (located below right
side of control box). Route leads through hole in bottom of control
box and make low- -voltage connections (See Fig. 11). Secure all cut
wires, so that they do not interfere with operation of unit.

HEAT ANTICIPATOR SETTING

See thermostat instructions for anticipator and cycle rate setup
details.
NOTE: For thermostat selection purposes, use 0.18 amp for the
approximate required setting. Failure to make a proper heat
anticipator adjustment will result in improper operation, discomfort
to the occupants of the conditioned space, and inefficient energy
utilization; however, the required setting may be changed slightly
to provide a greater degree of comfort for a particular installation.

TRANSFORMER PROTECTION

The transformer is of the energy- -limiting type. It is set to withstand
a 30- -sec. overload or shorted secondary condition.

PRE- -START- -UP

WARNING
!
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.
2. Do not operate compressor or provide any electric power
to unit unless compressor terminal cover is in place and
secured.
3. Do not remove compressor terminal cover until all
electrical sources are disconnected and tagged.
4. Relieve and recover all refrigerant from system before
touching or disturbing anything inside terminal box if
refrigerant leak is suspected around compressor terminals.
5. Never attempt to repair soldered connection while
refrigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure.
To remove a component, wear protective goggles and
proceed as follows:
a. Shut off electrical power to unit and install lockout
tag.
b. Relieve and reclaim all refrigerant from system
using both high- - and low- -pressure ports.
c. Cut component connecting tubing with tubing
cutter and remove component from unit.
d. Carefully unsweat remaining tubing stubs when
necessary. Oil can ignite when exposed to torch
flame.
Use the Start- -Up Checklist supplied at the end of this book and
proceed as follows to inspect and prepare the unit for initial start- -up:
1. Remove access panel.
2. Read and follow instructions on all DANGER, WARNING,
CAUTION, and INFORMATION labels attached to, or
shipped with unit.
3. Make the following inspections:
a. Inspect for shipping and handling damage, such as
broken lines, loose parts, disconnected wires, etc.
b. Inspect for oil at all refrigerant tubing connections and on
unit base. Detecting oil generally indicates a refrigerant
leak.
c. Leak- -test all refrigerant tubing connections using
electronic leak detector, or liquid- -soap solution. If a
refrigerant leak is detected, see following Check for
Refrigerant Leaks section.
d. Inspect all field- - and factory- -wiring connections. Be
sure that connections are completed and tight.
e. Ensure wires do not touch refrigerant tubing or sharp
sheet metal edges.
f. Inspect coil fins. If damaged during shipping and
handling, carefully straighten fins with a fin comb.
WARNING
!
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
Do not purge gas supply into the combustion chamber. Do not
use a match or other open flame to check for gas leaks.
4. Verify the following conditions:
a. Make sure gas line is free of air. Before lighting the unit
for the first time, perform the following with the gas valve
in the OFF position:
NOTE: If the gas supply pipe was not purged before connecting the
unit, it will be full of air. It is recommended that the ground joint
union be loosened, and the supply line be allowed to purge until the
odor of gas is detected. Never purge gas lines into a combustion
chamber. Immediately upon detection of gas odor, retighten the
union. Allow 5 minutes to elapse, then light unit.
b. Make sure that condenser- -fan blade is correctly
positioned in fan orifice. As a general rule , the top 1/3 of
condenser- -fan blade should be within fan orifice venturi.
c. Ensure fan hub is positioned correctly with respect to
motor housing (See Fig. 12).
d. Make sure that air filter(s) is in place.
e. Make sure that condensate drain trap is filled with water
to ensure proper drainage.
f. Make sure that all tools and miscellaneous loose parts
have been removed.
MOTOR
1/8" MAX BETWEEN
MOTOR AND FAN HUB
Fig. 12 - - Fan Blade Clearance
START- -UP
Step 1—CHECK FOR REFRIGERANT LEAKS
Proceed as follows to locate and repair a refrigerant leak and to
charge the unit:
1. Locate leak and make sure that refrigerant system pressure
has been relieved and reclaimed from both high- - and
low- -pressure ports.
2. Repair leak following accepted practices.
12
FAN GRILLE
1/2ý
MOTOR SHAFT
C99009