Pre-Start-Up - Carrier 50XZ024 Installation, Start-Up And Service Instructions Manual

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 – on the 060 size, only – the 2 wire ties
fastened to the
valve/accumulator have been removed.
e. Make sure that all tools and miscellaneous loose parts have
been removed.
outdoor coils and reversing
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.
MOTOR
1/8" MAX BETWEEN
MOTOR AND FAN HUB
Fig. 23—Fan Blade Clearance
Step 1—50XZ: Start-Up
CHECKING COOLING AND HEATING CONTROL OPERA-
TION– 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 according to time delay selected on the
Easy Select™ board (See Easy Select Section) when
FAN MODE switch is placed in AUTO position.
(2.) Thermostat:
When the room temperature rises to a point that is
slightly above the cooling control setting of the
thermostat, the thermostat completes the circuit be-
tween thermostat terminal R to terminals Y, O and G.
These completed circuits through the thermostat con-
nect contactor coil (C) (through unit wire Y) and ECM
board (through unit wire G) across the 24-v. secondary
of transformer (TRAN).
Thermidistat™ or Thermostat and Humidistat:
When the room temperature rises to a point that is
slightly above the cooling control setting of the
thermostat, the thermostat completes the circuit be-
tween thermostat terminal R to terminals Y, O, DH,
and G. These completed circuits through the thermo-
stat connect contactor coil (C) (through unit wire Y)
and ECM board (though unit wire G) across the 24-v.
secondary of transformer (TRANS).
(3.) Place system switch or MODE control in HEAT
position. Set control above room temperature. Observe
that compressor, outdoor fan, and indoor blower
motors start. Observe that heating cycle shuts down
according to time delay selected on the Easy Select™
board (See Easy Select Section) when control setting
is satisfied.
(4.) When using an automatic changeover room thermo-
stat, place both SYSTEM or MODE control and FAN
mode switches in AUTO positions. Observe that unit
operates in Cooling mode when temperature control is
set to "call for Cooling" (below room temperature),
and unit operates in Heating mode when temperature
control is set to "call for Heating" (above room
temperature).
18
FAN GRILLE
1/2˝
MOTOR SHAFT
START-UP
C99009