EarthLinked SC Series, Quick Start Instructions

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SC-410-QS (05/11) Page 34
6. There will be many bubbles in the sight glass as shown in Figure 28.
Figure 28. Initial Sight Glass Refrigerant Condition
7. After approximately 10 minutes, repeat step 5. Liquid must always be visible in the
Active Charge Control (ACC) but not allowed above the top sight glass for an
extended period of time.
8. Continue with this adjustment procedure repetitively until the refrigerant condition as
viewed in the in-line sight glass is such that bubbles have been reduced to a tiny
trickle, or many small bubbles, as shown in Figure 29. The suction temperature may
be greater than 35°F at final adjustment. If two hours have elapsed, many bubbles are
still present in the in-line sight glass and suction temperature is 35°F, the adjustment
is complete.
Figure 29. Final Sight Glass Refrigerant Condition
9. After the in-line sight glass refrigerant condition appears as in Figure 29 , check
the liquid level in the ACC and verify that it is visible.
10. Effects of adjusting the CAV clockwise are as follows:
a. Reduces suction temperature
b. Lowers liquid level in the ACC
c. Reduces bubbles in in-line sight glass
11. The conditions for completion of the CAV adjustment are:
a. Suction temperature must be at 35°F or above.
b. Liquid level in the ACC must be visible
c. Bubbles in the in-line sight glass must be a “trickle” or “many small
bubbles.”
d. CAV adjustment must be made at a return air temperature of 70°F for a
direct expansion air handler (or a chilled water return temperature of 45°F to
50°F).