Carrier 48KLA - Low-Voltage Wiring and Heat Anticipator; START-UP AND INITIAL OPERATION

Using cover removed from red lead, insulate loose
terminal on orange lead. Wrap cover with electrical
tape so that metal terminal cannot be seen.
NOTE: For some 48KHA,KLA units, the factory-
wired blower-motor speed connections may require
changing for 208-v operation to ensure adequate air¬
flow at the rated external static pressure. See unit
wiring label. Insulate all unused motor leads follow¬
ing same procedures described for transformer leads.
LOW-VOLTAGE CONNECTIONS — Use a suit¬
able room thermostat as specified on unit wiring
label.
Locate room thermostat on an inside wall in space
to be conditioned where it will not be subjected to
either a cooling or heating source, or direct exposure
to sunlight. Mount thermostat 4 to 5 ft above floor.
Use no. 18 AWG color-coded, insulated (35 C
minimum) wires to make low-voltage connections
between thermostat and unit. If thermostat is located
more than 100 ft from unit (as measured along the
low-voltage wires), use no. 16 AWG color-coded,
insulated (35 C minimum) wires.
A grommeted, low-voltage inlet hole is located in
the panel adjacent to control access panel. See Fig. 4.
Run low-voltage leads from thermostat, through
inlet hole and to low-voltage flagged pigtail leads
that run through a hole in bottom of unit control
box. See Fig. 6. Connect thermostat leads to pigtail
leads as shown in Fig. 8.
HEAT ANTICIPATOR SETTING — Room
thermostat heat anticipator must be properly ad¬
justed to ensure proper heating performance. Set
heat anticipator, using ammeter to determine exact
required setting.
NOTE: For thermostat selection purposes, use 1.0
amps for approximate required setting.
Failure to make a proper heat anticipator adjust¬
ment will result in improper operation, discomfort
to occupants of conditioned space and inefficient
energy use; however, required setting may be
changed slightly to provide a greater degree of com¬
fort for a particular installation.
START-UP
Unit Preparation
1. Follow recognized safety practices and wear pro¬
tective goggles when checking or servicing refrig¬
erant system.
2. Do not operate compressor or provide any elec¬
tric power to unit unless compressor terminal
cover is in place and secured.
3. Do not remove compressor terminal cover until
all electrical sources have been disconnected.
4. Relieve all pressure from system before touching
or disturbing anything inside terminal box if a
refrigerant leak is suspected around compressor
terminals.
5. Never attempt to repair a soldered connection
while refrigerant system is under pressure.
6. Do not use a torch to remove any component.
System contains oil and refrigerant under pres¬
sure. To remove a component, wear protective
goggles and proceed as follows:
a. Shut off gas supply first, and then electrical
power to unit.
b. Relieve all pressure from system.
c. Use tubing cutter to cut tubing that connects
component, and remove component from
unit.
d. Carefully unsweat remaining tubing stubs
when necessary. Oil can ignite when exposed
to torch flame.
-» PRE-START-UP PROCEDURES — Proceed as
follows to inspect and prepare unit for initial
start-up:
1. Remove all access panels.
2. Read and follow instructions on all WARNING,
CAUTION and INFORMATION labels at¬
tached to or shipped with the unit.
3. Make following inspections:
a. Inspect for shipping and handling damages
such as broken lines, loose parts, disconnected
wires, etc.
b. Inspect f or oil at all refrigerant tubing connec¬
tions and on unit base. The presence of oil
generally indicates a refrigerant leak. Leak-
test all refrigerant tubing connections using
electronic leak detector, halide torch or liquid
soap solution. If refrigerant leak is detected,
see Refrigerant Leaks in next section.
c. Inspect all field- and factory-wiring connec¬
tions. Be sure connections are completed and
tight.
d. Inspect coil fins. If damaged during shipping
and handling, carefully straighten fins with a
fin comb.
4. V erify the following conditions:
a. Make sure gas supply has been purged, and
all gas piping has been checked for leaks.
b. Make sure outdoor fan blade is correctly posi¬
tioned in fan orifice. Blades should clear fan
motor by no more than 114 inch.
c. Make sure air filter(s) is in place.
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