Daikin DP3G Series, Руководство по установке, Страница: 19 / 48

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2. Circulating Air Blower will continue to run for 120,
135 or 150 seconds, (single stage models) or 90,
120, 150, or 180 seconds (two-stage models),
depending on the setting.
PCBAG123 Control Board (Single Stage)
PCBAG127 Control Board (Two-Stage)
NOTE: If necessary, adjust fan OFF delay settings to obtain
satisfactory comfort level.
Unit Shutdown
1. Set the thermostat to lowest setting.
2. Turn off the electrical power supply to the unit.
3. Remove the heat exchanger door on the side of the
unit by removing screws.
4. Move the gas control valve switch to the OFF position.
Do not force.
5. Close manual gas shutoff valve external to the unit.
6. Replace the heat exchanger door on the unit.
7. If cooling and/or air circulation will be desired, turn
ON the electrical power.
Cooling Startup
NOTE: Check all manual reset limit controls in heating circuit
if cooling mode does not operate.
Compressor Protection Devices
The compressor includes components which are
designed to protect the compressor against abnormal
operating conditions.
WARNING
T
O PREVENT PERSONAL INJURY OR D EATH, ALWAYS D ISCONNECT ELECTRICAL
POWER BEFORE INSPECTING OR SERVICING T HE UNIT.
A
LL COMPRESSOR
PROTECTION DEVICES RESET AUTOMATICALLY, ENERGIZING T HE C ONTACTOR
AND OUTDOOR FAN.
Refrigerant Charge Check
After completing airflow measurements and adjustments
the unit’s refrigerant charge must be checked. The unit
comes factory charged, but this charge is based on 325
CFM per ton and minimum ESP per AHRI test conditions
(generally between .15 -.28 ESP). When air quantity or
ESP is different than above, the refrigerant charge must
be adjusted to the proper amount. All package units with
fixed orifice devices are charged using the super heat
method at the compressor suction line.
After superheat is adjusted it is recommended to check
unit sub-cooling at the condenser coil liquid line out. For
charge adjustments, see superheat and sub-cooling
charts shown for each model. See superheat chart below.
Checking Subcooling
NOTE: Units with a TXV should be charged to Subcool-
ing only.
SUBCOOLING FORMULA = SATURATED LIQUID LINE
TEMPERATURE - LIQUID LINE TEMPERATURE
EXAMPLE:
a. Liquid Line Pressure = 417 PSI
b. Corresponding Temp. = 120°F
c. Thermometer on Liquid line = 109°F.
To obtain the amount of subcooling, subtract 109°F from
120°F. The difference is 11° subcooling. See the specification
sheet or technical information manual for the design subcool -
ing range for your unit.
Checking Superheat
EXAMPLE:
a. Suction Pressure = 143 PSI
b. Corresponding Temp. = 50°F
c. Thermometer on Suction Line = 59°F
To obtain the degrees temperature of superheat, subtract
50.0 from 59.0°F. The difference is 9° Superheat. The
9° Superheat would fall in the ± range of allowable
superheat.
SUPERHEAT = SUCTION LINE TEMP - SAT. SUCTION
TEMP.
Superheat Adjustment
NOTE: Superheat adjustments should not be made until in -
door ambient conditions have stabilized. This could take up
to 24 hours depending on indoor temperature and humidity.