ClimaCool UCR 30, 50 and 70 tons Manual - Manual (Page 54)

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54
Refrigerant Charging Procedure
Refrigerant Charging
Once leak testing and evacuation are complete, refrigerant
charging may commence. Always refer to the unit
nameplate and guidelines within this section in order to
establish the quantity of refrigerant required. IMPORTANT:
Always introduce refrigerant into a system using a charging
manifold with gauges, along with a refrigerant scale to
accurately weigh the refrigerant cylinder throughout the
entire charging process. As noted in an earlier section, the
end user and installing contractor must provide and fi eld
charge refrigerant R-410A.
CAUTION: Never dispense refrigerant amounts into the
receiver which may exceed its liquid holding capacity. The
refrigeration system in our model UCR 030 is equipped
with 72 pound receivers (at 80% full). Both refrigeration
systems in models UCR050 and UCR070 are equipped with
84 pound receivers (at 80% full).
As much refrigerant as possible should be charged in this
manner until the receiver holding capacity is achieved, or
system pressures equalize preventing additional refrigerant
from being added. Even if system equalization occurs, it is
still possible to inject liquid refrigerant into the system by
placing the refrigerant cylinder into a luke warm water bath.
NO WARMER THAN 110°F.
SAFETY ALERT: Cylinder pressures must be closely
monitored whenever a refrigerant cylinder is being heated
in ANY manner. Allowing pressures to exceed those for
which the cylinder is rated, may result in cylinder rupturing,
personal injury and/or property damage or even death.
Once system and refrigerant cylinder tank pressures have
equalized, it will be necessary to fi nish the refrigerant
charging process by gradually metering small bursts of liquid
refrigerant into the suction line of the compressor while it is
operating.
SAFETY ALERT: Never attempt to vapor charge into
the system high side, whether the compressor is ON
or OFF. This may result in refrigerant fl owing from the
refrigeration system into the charging cylinder. Cylinders
can quickly be over pressurized causing them to rupture
with resultant injury and property damage.
IMPORTANT: Never dispense liquid refrigerant into the
suction port of a compressor while it is not running.
If adding additional refrigerant is necessary, you must
gradually meter liquid refrigerant into the suction port
of the compressor ONLY WHILE THE COMPRESSOR IS
RUNNING, and only through a metering valve.
The only exception to the above recommendations to meter
in liquid refrigerant into the suction line is the following:
Providing the ENTIRE contents of the refrigerant cylinder
is intended to be added to a refrigeration system, it is
perfectly acceptable to vapor charge from this cylinder into
the compressor suction line until all refrigerant is injected.
The amount of refrigerant required in a system depends on
the following:
• Model size of the equipment.
• The distance of the interconnecting lines between the
UCR module and the condenser section.
• The specifi c head pressure control methods used for
low ambient operation.
• What (if any) fan cycling controls are supplied with the
condenser.
• Whether optional compressor unloading is possible
using hot gas bypass.
Refer to Tables 1 and 2 to determine the total amount of
additional refrigerant at initial startup which accommodates
all dependant variables listed above. Although the charge
in the table refers to a winter charge, it is suitable for both
winter and summer operation.