Special Procedures For 208-Voperation; Pre-Start-Up - Carrier 50HS018 Installation, Start-Up And Service Instructions Manual

SPECIAL PROCEDURES FOR 208-V OPERATION
Make sure that the power supply to the unit is switched
OFF before making any wiring changes. Electrical shock
can cause personal injury or death.
1. Disconnect the orange transformer-primary lead from the
contactor. See unit wiring label.
2. Remove the wirenut from the terminal on the end of the
red transformer-primary lead.
3. Save the wirenut.
4. Connect the red lead to the contactor terminal from which
the orange lead was disconnected.
5. Using the wirenut removed from the red lead, insulate
the loose terminal on the orange lead.
6. Wrap the wirenut with electrical tape so that the metal
terminal cannot be seen.
Indoor blower-motor speeds may need to be changed for
208-v operation. Refer to Indoor Airflow and Airflow Ad-
justments section on page 22.

PRE-START-UP

Failure to observe the following warnings could result
in serious personal injury:
1. Follow recognized safety practices and wear protec-
tive 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.
4. Relieve all pressure from both high- and low-
pressure sides of the system before touching or dis-
turbing anything inside terminal box if refrigerant leak
is suspected around compressor terminals. Use ac-
cepted methods to recover refrigerant.
5. Never attempt to repair soldered connection while re-
frigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure. To re-
move a component, wear protective goggles and pro-
ceed as follows:
a. Shut off electrical power to unit.
b. Relieve all pressure from system using both high-
and low-pressure ports. Use accepted methods to
recover refrigerant.
c. Cut component connecting tubing with tubing cut-
ter 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 all access panels.
2. Read and follow instructions on all WARNING, CAU-
TION, and INFORMATION labels attached to, or shipped
with, unit.
Make the following inspections:
a. Inspect for shipping and handling damages such as bro-
ken lines, loose parts, disconnected wires, etc.
b. Inspect for oil at all refrigerant tubing connections and
on unit base. Detecting oil generally indicates a re-
frigerant leak. Leak-test all refrigerant tubing connec-
tions using electronic leak detector, or liquid-soap so-
lution. If a refrigerant leak is detected, see Check for
Refrigerant Leaks section, page 18.
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 han-
dling, carefully straighten fins with a fin comb.
3. Verify the following conditions:
a. Make sure that outdoor-fan blade is correctly posi-
tioned in fan orifice. Leading edge of blade should be
2 in. back from condenser inlet grille.
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.
4. If the unit is equipped with a crankcase heater, start the
heater 24 hours before starting the unit. To start the heater
only, turn the thermostat to the OFF position and ener-
gize the electrical disconnect to the unit.
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