Carrier 50JZ024, Installation, Start-Up And Service Instructions Manual

Page: 14 / 28

SPECIAL PROCEDURES FOR 208V OPERATION
1. Be sure unit disconnect switch is open.
2. Disconnect the yellow primary lead (w110) from the trans-
former. See unit wiring label (Fig. 12 and 13).
3. Connect the yellow primary lead (w110) to the transformer
terminal labeled 200v.
Indoor blower-motor speeds may need to be changed for 208v
operation. Refer to indoor airflow and airflow adjustments section.
PRE-START-UP
Failure to observe the following warnings could result in
serious 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 electri-
cal sources are disconnected.
4. Relieve and recover all refrigerant from both high- and
low-pressure sides of 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 refrig-
erant 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.
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 neces-
sary. 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 all access panels.
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 damages 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. Leak-test all refrigerant tubing connections using
electronic leak detector, or liquid-soap solution. If a refrig-
erant leak is detected, see following Check for Refrigerant
Leaks section.
c. Inspect all field and factory-wiring connections. Be sure
that connections are completed and tight.
d. Inspect coil fins. If damaged during shipping and handling,
carefully straighten fins with a fin comb.
4. Verify the following conditions:
a. Make sure that outdoor-fan blade is correctly positioned in
fan orifice.
b. Make sure that air filter(s) is in place.
c. Make sure that condensate drain pan and trap are filled with
water to ensure proper drainage.
d. Make sure that all tools and miscellaneous loose parts have
been removed.
5. Compressors are internally spring mounted. Do not loosen or
remove compressor hold-down bolts.
6. Each unit system has 2 Schrader-type ports, one low-side
Schrader fitting located on the suction line, and one high-side
Schrader fitting located on the compressor discharge line. Be
sure that caps on the ports are tight.
START-UP
Using the Start-Up Checklist supplied at the end of this book,
proceed as follows:
Step 1—Check for Refrigerant Leaks
Locate and repair refrigerant leaks and charge the unit as follows:
1. Use both high- and low-pressure ports to relieve system
pressure and reclaim remaining refrigerant.
2. Repair leak following accepted practices.
NOTE: Replace biflow filter drier whenever the system has
been opened for repair.
3. Check system for leaks using an approved method.
4. Evacuate refrigerant system and reclaim refrigerant if no
additional leaks are found.
5. Charge unit with R-410A refrigerant, using a volumetric-
charging cylinder or accurate scale. Refer to unit rating plate
for required charge.
Step 2—Start-Up Adjustments
Complete the required procedures given in the Pre-Start-Up
section on this page before starting the unit. Do not jumper any
safety devices when operating the unit. Do not operate the unit in
Cooling mode when the outdoor temperature is below 40°F (unless
accessory low-ambient kit is installed). Do not rapid-cycle the
compressor. Allow 5 minutes between ‘‘on’’ cycles to prevent
compressor damage.
CHECKING COOLING AND HEATING CONTROL OPERA-
TION — Start and check the unit for proper control operation as
follows:
Fig. 19—Transformer Label
C99058
TRANSFORMER CONTAINS A MANUAL
RESET OVERCURRENT PROTECTOR
IT WILL NOT AUTOMATICALLY RESET
DISCONNECT POWER PRIOR TO
SERVICING
THIS COMPARTMENT MUST BE CLOSED
EXCEPT WHEN SERVICING
Fig. 20—Fan Blade Clearance
C99009
FAN GRILLE
MOTOR
1/8" MAX BETWEEN
MOTOR AND FAN HUB
MOTOR SHAFT
14