United CoolAir VariCool EZ-Fit Series, Installation, Operation And Maintenance Manual

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Installation, Operation and Maintenance Manual
VariCool EZ-Fit
37
Subject to change without notice.
Start-Up Procedures (R-410a Systems)
Continued:
1� If possible, record the fluid flow rate (GPM)
a� Make sure the flow rate is within the proper limits:
i� Minimum 25 GPM / Ton
ii�
Maximum 35 GPM / Ton
2� Record the entering and leaving fluid temperatures
b� Make sure the leaving fluid temperature is within the
proper limits:
i� Minimum 60˚ F
ii�
Maximum 115˚ F
3� Record the pressure drop of the water / fluid across the
unit
4� Verify that all valves on each fluid circuit function
properly
5� Record the suction line pressure and the suction line
temperature for each circuit near the compressor
6�
Using an appropriate pressure / temperature chart for
R-410a refrigerant, look up and record the saturation
temperature corresponding to the suction pressure
7� 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
8� Record the liquid line pressure and the liquid line
temperature for each circuit near the condenser heat
exchanger outlet
9� Using an appropriate pressure / temperature chart for
R-410a refrigerant, look up and record the saturation
temperature corresponding to the liquid line pressure
10�
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
11� Record the Amps for the evaporator blower motor and
each compressor 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 value 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
12� Document any additional information deemed
appropriate for the specific application or installation
13� Shut the system down and remove all test instruments
and test sensors
14� Leave the system in the operating mode as appropriate
for the customer and the application
Optional Heating Start Up:
15� If the system has any optional heat, set the room
thermostat approximately 5 ° higher than the actual
room temperature Set the thermostat operating mode
to the HEAT position
16� Dependent upon the heating source the heating valve
or switch / contactor should be activated
17� After several minutes of operation, record the return air
temperature and the supply air temperature
18� Based on the heating source, document the
appropriate temperatures, pressures, voltage or amp
values