ClimaCool UCA Manual - Manual (Page 23)

23
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Startup
All startups must be performed by ClimaCool factory
trained personnel.
1. Built into the logic of the CoolLogic Control System
is an anti-short cycle timer which will prevent the
compressors from re-starting immediately following a
compressor shutdown.
2. If the chilled water temperature is above the normal
operating level (greater than 90°F), all load should be
removed from the chilled water system and the suction
temperature should be monitored to prevent high
current draw.
3. When all temperatures are within operating limits, all
high and low pressure safety switches should be tested
for each refrigeration system.
4. Once stable conditions have been achieved, the
refrigeration system’s high and low pressures,
compressor amp draw, voltage input level, and water
system temperatures and pressures should be logged
for each chiller module separately.
5. Check that the oil level is between 1/3 and 1/2 of the
sight glass. (See page 31– Oil Levels).
6. The action of the controller should be checked for
correct operation and control.
7. Extract three water samples from the evaporator
water system using bottles provided from the water
sample test kit. Confi rm that the sample bottles are
fi lled to the top leaving no air in the bottles. All three
sample bottles must have labels fi lled out per the
instructions included with the bottles. Ship the bottles
immediately to the appropriate water testing laboratory
per the instructions included with the bottles.
Adjusting Unit Charge and TXV’s Using Superheat
and Subcooling Method
Due to varying installation conditions/applications and
to optimize performance, proper refrigerant charge and
TXV adjustment must be confi rmed. This process must be
performed in cooling mode only.
After checking compressor rotation, choose a circuit to be
tested fi rst. Connect test equipment to monitor the suction
line and liquid line temperatures simultaneously. Place a
manifold gauge set on the suction line and liquid line and
start the compressor. As long as the suction pressure is high
enough to prevent the low pressure switch from tripping,
run the compressor for fi ve minutes.
Verify proper superheat by subtracting the saturated
evaporative temperature from the suction line temperature.
The saturated evaporative temperature is found by
converting the suction pressure reading on the manifold
gauge to the related temperature. The proper superheat
temperature range is 6-12°F. If superheat is low, this may
indicate that TXV is overfeeding. To adjust the TXV, turn the
adjustment stem clockwise. This will cause the superheat
to rise. Wait fi ve minutes before checking results of the
adjustment. Repeat until desired superheat is achieved.
After verifying proper superheat, then verify proper
subcooling. This is accomplished by subtracting the
liquid line temperature from the saturated condensing
temperature. Saturated condensing temperature is found by
converting the liquid line pressure reading on the manifold
gauge, to the related temperature. Normal subcooling
temperature range at the condenser is 5 – 15°F BUT for total
accuracy please follow the charge recommendations found
in the selection program. If subcooling is too low, then
refrigerant must be added to the system. Add the charge
and wait fi ve minutes before checking results. If subcooling
is too high, then refrigerant must be removed from the
system.