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P a g e
moment, slightly heat up the refrigerant tank with a portable heater to increase
internal pressure of the tank.
4.
The other way to charge the refrigerant is to increase the height of the refrigerant
tank. Lift the refrigerant tank above the condenser so the liquid refrigerant will
flow into the condenser under gravitational force.
5.
When the charging weight reaches 75% of the refrigerant tank, connect the
charging hose to the access valve located at suction pipe. Let the chiller run, low
suction pressure will pull in refrigerant from the tank.
6.
After Charging, run the chiller and record the operating data.
!
Cleaning and Maintenance
A dirty system may cause chiller to trip, so routine maintenance is indispensable.
Reasons for dirty system:
1. Eliminate dirt in water filter. The filter must be replaced or wash frequently.
2. Perform condenser coil cleaning and maintenance if necessary.
7.3.1
Relief Valve replacement
All the vessels of UAA chillers have 1 relief valve. One is working and the other
standby. The relief valve needs to send for calibration every year to ensure its
functionality. To take out the relief valve, shut off the ball valve located below
the relief valve.
7.3.2
Pump down
If pump down is necessary for maintenance and checking purpose, perform it
with extreme care in order to avoid freezing in evaporator. Always make sure
there is water flow throughout the pump down process. To perform pump down,
close all liquid line ball valves and let the chiller run. Chiller will trip under low
mechanical pressure switch.
7.3.3
Pressure Test
No pressure testing is necessary unless some damages happened during
shipment. Damage can be detected by a visual inspection of the exterior piping,
loose fitting. Pressure gauge should show a positive pressure. If the reading is
0kPa, there might be a potential leak. In this case, the unit must be leak tested
to determine the location of the leak.
7.3.4
Leak Test
In the case of low refrigerant charge, a leak test must be performed before
charging refrigerant. Use a refrigerant leak detector. Water flow must be
maintained in evaporator when refrigerant is added or removed from the system.
Summary of Contents for UAA-ST3M
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Page 17: ...13 P a g e UAA 105 UAA 150 UAA175 UAA220 UAA204 220...
Page 18: ...14 P a g e Figure 7 Hanging Method UAA245 UAA348 UAA380 UAA450...
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