While charging during the summer, meter refrigerant through the suction line until the level of
liquid in the receiver sight glass is approximately 1/3 from the bottom (the level ball in the
receiver will start to float) of the sight glass. A liquid charging adapter should be used to
prevent liquid refrigerant from entering the compressor. Charge each circuit to the value
shown in the
Table 7 Packaged Units with Receivers
below.
See 5.7.3
Charging the Fixed Speed
Compressor for charging the fixed speed compressor
except use the table below for the proper charge conditions.
Water/Glycol-Cooled System Charging
All water/glycol cooled units are factory charged with refrigerant. The superheat at the
compressor suction line at least 6 inches (152 mm) away from the compressor. The water
regulating valve should be adjusted to maintain the required conditions. Field charging, if
required, of water/glycol systems should be done by referring to the unit’s electrical
nameplate. The factory charge is indicated on the nameplate. Although this figure represents
the initial factory charge, it is still necessary to measure and note proper unit operation
including superheat, head and suction pressure. Some adjustment of charge may be required.
Adjust the refrigerant charge until the sight glass has sparse bubbles. The system should be
allowed to stabilize for 15 to 20 minutes before meaningful measurements can be taken. After
the system stabilize, verification of a few key measurements should be noted.
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