Installation, Operation and Maintenance Manual
VariCool
®
VAV
31
Subject to change without notice.
10.20-IM (0818)
Start-Up Procedures
(R-410a Systems)
Continued:
21�
Using an appropriate pressure / temperature chart for
R-410a refrigerant, look up and record the saturation
temperature corresponding to the suction pressure
22�
Calculate and record the suction superheat for each
circuit by taking the difference between the suction
line temperature and the saturation temperature
corresponding to the suction pressure
23�
Record the liquid line pressure and the liquid line
temperature for each circuit near the condenser coil
outlet
24�
Using an appropriate pressure / temperature chart for
R-410a refrigerant, look up and record the saturation
temperature corresponding to the liquid line pressure
25�
Calculate and record the liquid sub-cooling for each
circuit by taking the difference between the liquid
line temperature and the saturation temperature
corresponding to the liquid line pressure
26�
Record the Amps for the evaporator blower motor, each
compressor and the condenser blower motor If the
system is single phase, use L1 and L2 only
a�
Make sure the pressures on each compressor circuit
are within the proper limits:
i�
290 – 550 Discharge
ii�
100 – 140 psig Suction
b�
Compressor Amperage is below the RLA Amps
listed on the unit data tag
i�
The maximum compressor operating current
(amps) at start up depends a lot on the system
loading The lower the load, the less the current
The higher the load, the higher the current
c�
The blower motor FLA values should never be
exceeded
i�
If the FLA value is exceeded, shut the unit off
and check the duct design, sheave turns open
or make sure there is no blockage / obstruction
in the duct or filters.
27�
Document any additional information deemed
appropriate for the specific application or installation.
28�
Shut the system down and remove all test instruments
and test sensors
29�
Leave the system in the operating mode as appropriate
for the customer and the application
Optional Heating Start Up:
30�
If the system has any optional heat, set the room
thermostat approximately 5
°
higher than the actual
room temperature Set the controller operating mode to
the HEAT position
31�
Dependent upon the heating source the heating valve
or switch / contactor should be activated
32�
After several minutes of operation, record the return air
temperature and the supply air temperature
33�
Based on the heating source, document the
appropriate temperatures, pressures, voltage or amp
values
Summary of Contents for AVW08
Page 2: ......
