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CGAT-IOM01-EN
Operation
Start-up Procedure
1. Energize the evaporator water
pump.
2. Energize the CGAT unit.
3. Checking operating conditions
Once the unit has been operating
for at least 15 minutes and
the system has stabilized,
the following procedures are to be
done.
a. Re-check the evaporator water
flow and pressure drop.
b. Measure unit suction and
discharge pressures. The
normal operating suction
pressure is between 63 to 68
psig while the discharge
pressure range in between 270
psig to 300 psig.
c. Check compressor amp. Draw
NOTE : Many application variables
exists which can affect operating
pressures; these include ambient dry
bulb, wind velocity, restrictions in
airflow etc. As such, do not use
operating pressures as the sole check
of system operation.
4. Measure system superheat. Normal
system superheat is 12 to 15 deg. F
for each circuit at ARI conditions
(54 deg. F entering water, 44 deg.F
leaving water at 95 deg.F ambient
temperature).
5. Measure system subcooling
Normal subcooling for each circuit
is 12 to 16 deg.F at ARI conditions.
6. If operating pressure, superheat
and subcooling readings indicate
refrigerant shortage, find and repair
leaks and gas-charge refrigerant
into each circuit. Refrigerant
shortage is indicated it operating
pressures are low and subcooling
is also low.
CAUTION : If suction and discharge
pressures are low, but subcooling is
normal, no refrigerant shortage exists.
Adding refrigerant will result in
overcharging.
7. Add refrigerant vapor with the unit
running by charging through
the access port on the suction line
until operating pressures are
normal. Allow sufficient time
(between 15 to 30 minutes) before
taking readings.
CAUTION : To prevent compressor
damage, do not allow liquid refrigerant
to enter the suction line.
8. If operating pressures indicate
an overcharge, slowly (to minimize
oil loss) recover refrigerant at
the liquid line access port.
Important note : Do not release
refrigerant to the atmosphere.
Use proper refrigerant recovery
process.
WARNING : To prevent injury due to
frostbite, avoid skin contact with
refrigerant.
9. Check compressor oil levels. At full
load, oil level should be visible in
the oil level sight glass on the
compressor.
10.Inspect the unit. Remove any
debris, tools and hardware. Secure
all exterior panels.
13
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