Check For Refrigerant Leaks - Carrier 50XZ024 Installation, Start-Up And Service Instructions Manual

LEGEND
HPS – High Pressure Switch
LCS – Loss of Charge Switch
Accurater
Arrow indicates direction of flo w
NOTE: Once the compressor has started and then has stopped, it
should not be started again until 5 minutes have elapsed. The
cooling cycle remains ''on'' until the room temperature drops to
point that is slightly below the cooling control setting of the room
thermostat. At this point, the thermostat ''breaks'' the circuit
between thermostat terminal R to terminals Y and G. These open
circuits de-energize contactor coil C and ECM board. The
condenser and compressor motors stop. After the time delay
setting selected on the Easy Select™ board (See Easy Select
Section) , the blower motor stops. The unit is in a ''standby''
condition, waiting for the next ''call for cooling'' from the room
thermostat. The 5 minute compressor delay also applies to heat
pump heating mode.
Step 2—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: Install a bi-flow 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 3—Start-Up Adjustments
Complete the required procedures given in the Pre-Start-Up
section 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 min. between "on" cycles to prevent compressor damage.
OUTDOOR COIL
HP S
® Metering De vice
Fig. 24—Typical Heat Pump Operation, Cooling Mode
TXV in Metering
Position
LCS
Bypass
Position
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 within 60
sec (030-060 size) or 30 sec (024 size) when FAN MODE
switch is placed in AUTO position.
2. 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 when control setting is satisfied.
3. When using an automatic changeover room thermostat, 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).
IMPORTANT: Three-phase, scroll compressors are direction ori-
ented. Unit must be checked to ensure proper compressor 3-phase
power lead orientation. If not corrected within 5 minutes, the
internal protector will shut off the compressor. The 3-phase power
leads to the unit must be reversed to correct rotation. When turning
backwards, the difference between compressor suction and dis-
charge pressures may be dramatically lower than normal.
CHECKING AND ADJUSTING REFRIGERANT CHARGE
The refrigerant system is fully charged with R-410A refrigerant
and is tested and factory sealed.
NOTE: Adjustment of the refrigerant charge is not required
unless the unit is suspected of not having the proper R-410A
charge. The charging label and the tables shown refer to system
temperatures and pressures in Cooling mode, only. A refrigerant
charging label is attached to the outside of the service access door.
If charge level is suspect in Heating mode, reclaim all refrigerant
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INDOOR COIL
C03011