Carrier PA3Z-B, Руководство по установке

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Step 3 — Refrigerant Charge
Refrigerant Charge — The refrigerant system is fully charged with
R--410A refrigerant and is tested and factory sealed. Amount of
refrigerant charge is listed on unit nameplate and in Table 1. Unit
must operate a minimum of 15 minutes before checking charge.
NOTE : Adjustment of the refrigerant charge is not required unless
the unit is suspected of not having the proper R--410A charge.
NOTE : Unit sizes 024--048 have fixed orifice refrigerant metering
devices, the 060 size has a TXV. There is a different charging
procedure for both expansion devices. Refer to the correct
procedure for your unit.
NO CHARGE
Use standard evacuating techniques. After evacuating system,
weigh in the specified amount of refrigerant (refer to Table 1).
LOW CHARGE COOLING
024--048 Units, Fixed Metering Device:
1. Operate unit a minimum of 10 minutes before checking
charge.
2. Measure suction pressure by attaching an accurate gauge to
compressor suction side service port.
3. Measure suction side temperature by attaching an accurate
thermisitor type or electronic thermometer to suction line
about 10 in. from compressor.
4. Measure outdoor air dry--bulb temperature with thermo-
meter.
5. Measure indoor air (return air) wet--bulb temperature with a
sling psychrometer or electronic equivalent.
6. Using Superheat Charging Table (Table 3) find outdoor
temperature and indoor air wet--bulb temperature. At this
intersection note superheat. Where a dash (----) appears on
table do not attempt to charge unit under these conditions or
refrigerant slugging may occur. In this situation refrigerant
must be evacuated and weighed in. See rating plate for
charge quantity.
7. Refer to Required Suction Tube Temp. Table (Table 3).
Find superheat temperature located in Step 6 and suction
pressure. At this intersection note suction line temperature.
8. If unit has a higher suction line temperature than charted
temperature, add refrigerant until charted temperature is
reached.
9. If unit has a lower suction line temperature than charted
temperature, reclaim refrigerant until charted temperature is
reached.
10. If outdoor air temperature or pressure at suction port
changes, charge to new suction line temperature indicated
on chart.
060 Units, TXV Metering Device::
1. Measure discharge line pressure by attaching a gauge to the
service port.
2. Measure the liquid line temperature by attaching a
temperature sensing device to it.
3. Insulate the temperature sensing device so that the outdoor
ambient doesn’t affect the reading.
4. Refer to the required subcooling in Table 4 to find the
required subcooling based on the model type and the
outdoor ambient temperature.
5. Interpolate if the outdoor temperature lies in between the
table values.
6. Find the pressure value corresponding to the measured
pressure on the compressor discharge line.
7. Read across from the pressure reading to obtain the Liquid
line temperature for a required subcooling.
8. Add charge if the measured temperature is higher than the
liquid line temperature value in the table.
9. Remove charge if the measured temperature is lower than
the table value.
Step 4 — Indoor Airflow and Airflow Adjust-
ments
UNIT OPERATION HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
For cooling operation, the recommended airflow is 350 to
450 cfm for each 12,000 Btuh of rated cooling capacity.
!
WARNING
Table 5 shows wet coil air delivery for horizontal discharge units.
Table 6 and Table 7 show pressure drops.
NOTE
: Be sure that all supply-- and return--air grilles are open,
free from obstructions, and adjusted properly.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect electrical power to the unit and install lockout
tag before changing blower speed.
!
WARNING
Blower speed tap can be changed by replacing the factory installed
blue low speed tap wire (cooling) with the unused black high speed
wire in unit control box. The red medium speed wire is factory
installed to operate with a call for supplemental electric heat. See
unit wiring diagram. Be sure new airflow meets the range noted
above the minimum electric heat CFM, if equipped. Refer to Table
2.
All model sizes are factory wired for rated airflow operation.
Step 5 — Sequence of Operation
FAN OPERATION
The FAN switch on the thermostat controls indoor fan operation.
When the FAN switch is placed in the ON position, the indoor
(evaporator) fan motor (IFM) is energized through the G terminal
on the thermostat. The motor’s internal logic then provides power
to the indoor (evaporator) fan motor (IFM). The IFM will run
continuously when the FAN switch is set to ON.
When the FAN switch is set to AUTO, the thermostat deenergizes
the IFM (provided there is not a call for cooling).
NOTE
: All motors on this product are programmed for 60 sec
time delay on tap 1 and 30 sec time delay on tap 2. There is no
time delay on tap 3. The indoor fan will remain on for the set time
delay after G or W2 is deenergized.
COOLING OPERATION
With a call for cooling (Y), the indoor fan, compressor, and the
outdoor fan motor are energized. When the cooling demand is met,
Y de--energizes, shutting off the compressor, indoor fan, and the
outdoor fan.
PA
3Z
B