Reznor ZQYRA Unit Installation Manual - Manual (Page 65)

Form I-ZQYRA P/N 260414R5, Page 65
Compressor - The scroll compressor has a digital controller (Paragraph 7.4.3) that
interfaces the system controller and compressor operation. The controller has its own
alarm system; see the Troubleshooting Chart in Paragraph 10.3.2.
Checking Subcooling and Superheat - At startup and during service, checking sub-
cooling and superheat is required to verify proper operation of the thermal expansion
valve and refrigerant charge.
10.2.5 Heat Pump
Maintenance
Instructions for Checking and Adjusting the Subcooling (applies to COOLING
MODE ONLY) - Acceptable subcooling readings range from 10° to 14°F (5.5° to
7.8°C).
Measure and record temperature and pressure of the liquid line at the condenser coil
outlet.
STEP 1) Record Measurements: Temperature = ________°F (°C) and Pressure =
________ psig
STEP 2) From Temperature/Pressure Conversion Chart (left), convert
Measured Pressure (STEP 1) to ________°F (°C)
STEP 3) Subtract Measured Temperature (STEP 1) from Temperature from
Conversion Chart (STEP 2) _______°F (°C) - ________°F (°C) =
________°F (°C) degrees of Subcooling
Too much subcooling indicates a refrigerant overcharge. To reduce the subcooling,
remove excess refrigerant. Too little subcooling indicates a refrigerant undercharge. To
increase subcooling, slowly add R-410A refrigerant.
WARNING
Do not release refrigerant to the atmosphere. When adding or
removing refrigerant, the qualified technician must comply with
all national, state/province, and local laws.
Instructions for Checking and Adjusting the Superheat (applies to both
COOLING AND HEATING MODE) - Superheat should be in the 8° to 12°F
(4.5° to 6.7°C) range.
Measure and record temperature (insulate probe from surrounding air
temperature) and pressure in the suction line at the compressor inlet.
STEP 1) Record Measurements: Temperature = _______°F (°C) and Pressure =
_______ psig
STEP 2) From Temperature/Pressure Conversion Chart (left), convert
Measured Pressure (STEP 1) to _______°F (°C)
STEP 3) Subtract Measured Temperature (STEP 1) from Temperature from
Conversion Table (STEP 2) _______°F (°C) - ________°F (°C) =
________°F (°C) degrees of Superheat
Typically too much superheat indicates that the evaporator coil is undercharged.
Too little superheat typically indicates that the evaporator coil is overcharged and
may potentially flood liquid refrigerant to the compressor. To reduce the superheat,
adjust the thermal expansion valve by turning the adjusting stem counterclockwise. To
increase the superheat, adjust the thermal expansion valve by turning the adjusting
stem clockwise.
Pressure/Temperature Chart
for Checking Superheat &
Subcooling
Saturation
Temperature
Pressure
(psig)
(°F) (°C) R410A
0 -17.8 48.2
5 -15.0 55.0
10 -12.2 62.3
15 -9.4 70.2
20 -6.7 78.7
25 -3.9 87.8
30 -1.1 97.5
35 1.7 107.9
40 4.4 118.9
45 7.2 130.7
50 10.0 143.3
55 12.8 156.6
60 15.6 170.7
65 18.3 185.7
70 21.1 201.5
75 23.9 218.2
80 26.7 235.9
85 29.4 254.6
90 32.2 274.3
95 35.0 295.0
100 37.8 316.9
105 40.6 339.9
110 43.3 364.1
115 46.1 389.6
120 48.9 416.4
125 51.7 444.5
130 54.4 474.0
135 57.2 505.0
140 60.0 537.6
145 62.8 571.7
150 65.6 607.6
155 68.3 645.2
NOTE: Information in the pressure/
temperature chart was taken
from the Temperature Pressure
Chart printed in Form IC-2-04
by the Sporlan Valve Company,
Washington, MO 63090.
Pulley - the pulley is secured to the drive motor shaft by a set screw. The set screw is
secured with removable Locktite to prevent loosening. Confirm the set screw is secure.
Belt - The belt is of urethane stretch material and is designed to provide constant ten-
sion. There is no type of adjustment. Inspect the belt for proper tracking and tension. If
a belt needs replaced, it must be replaced with a factory-authorized replacement (Size
8, P/N 262488; Size 12, P/N 262489). Follow the wheel manufacturer’s instructions.
NOTE: A properly tensioned belt will turn the wheel immediately after power is applied with no visible slippage during
startup. The belt should track approximately 1/4” from the outer edge of the rim.
If the belt or any other component needs replaced, use only factory-authorized replacement designed for the purpose.
Follow instructions provided by the wheel manufacturer.