Carrier Performance 50VR-A, Installation Instructions Manual

Page: 11 / 38

11
PRE--START--UP
!
WARNING
ENVIRONMENTAL, FIRE, EXPLOSION,
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death and/or property damage.
1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.
2. Relieve and recover all refrigerant from system before
touching or disturbing compressor plug if refrigerant
leak is suspected around compressor terminals.
3. Never attempt to repair soldered connection while
refrigerant system is under pressure.
4. Do not use torch to remove any component. System
contains oil and refrigerant under pressure.
5. 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 all access panels (see Fig. 21).
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 refrigerant 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. Ensure
wires do not touch refrigerant tubing or sharp sheet
metal edges.
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. Each unit system has two (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
Step 1 — Check Cooling and Heating Control
Operation
Start and check the unit for proper control operation as follows:
1. Place room thermostat SYSTEM switch or MODE control
in OFF position. Observe that blower motor starts when
FAN mode is placed in FAN ON position and shuts down
when FAN MODE switch is placed in AUTO position.
2. Thermostat:
On a typical two stage thermostat, when the room temper-
ature rises 1 or 2 degrees above the cooling control setting
of the thermostat, the thermostat completes the circuit
between thermostat terminal R and terminals Y1, and G.
These completed circuits through the thermostat connect the
contactor coil (C) (through unit wire Y1) and indoor fan
board (through unit wire G) across the 24--v. secondary of
transformer (TRAN).
On a typical two stage thermostat, when the room temperat-
ure is several degrees above the cooling control setting of
the thermostat, the thermostat completes the circuit between
terminal R and terminals Y1, Y2 , and G.
3. If your unit contains accessory electric heat, place system
switch or MODE control in HEAT position. Set control
above room temperature. Observe that the indoor blower is
operating and warm air is flowing through the supply air
vents inside your home. Observe that the heating cycle
shuts down when the control setting is satisfied.
If your unit does not contain accessory electric heat and you
would like to obtain it, please contact your local dealer for
more information.
4. When using an automatic changeover room thermostat
place both SYSTEM or MODE control and FAN mode
stitches in AUTO positions. Observe that unit operates in
Cooling mode when temperature control is set to “call for
Cooling” (below room temperature).
NOTE : Once the compressor has started and then has stopped, it
should not be started again until 5 minutes have elapsed.
Step 2 — Check for Refrigerant Leaks
EXPLOSION HAZARD
Failure to follow this warning could
result in death, serious personal injury,
and/or property damage.
Never use air or gases containing
oxygen for leak testing or operating
refrigerant compressors. Pressurized
mixtures of air or gases containing
oxygen can lead to an explosion.
!
WARNING
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 Refrigerant Service procedures.
NOTE : Install a filter drier whenever the system has been opened
for repair.
3. Add a small charge of R--410A refrigerant vapor to system
and leak--test unit.
4. Recover refrigerant from refrigerant system and evacuate to
500 microns if no additional leaks are found.
5. Charge unit with R--410A refrigerant, using an electronic
scale. Refer to unit rating plate for required charge.
50V
R