Liebert 50 & 60Hz - Manual (Page 23)

Site Preparation and Installation
15
Refrigerant Charge Requirements: Total refrigerant charge (R-22) will be required only if units
are evacuated during installation or maintenance. For safe and effective operation, refer to 2.4.3 -
Piping Connections and Coolant Requirements.
Total refrigerant = Units and Lines
Quick Connect Fittings
Be especially careful when connecting the quick connect fittings. Read through the following steps
before making the connections.
1. Remove protector caps and plugs.
2. Carefully wipe coupling seats and threaded surfaces with a clean cloth.
3. Lubricate the male diaphragm and synthetic rubber seal with refrigerant oil.
4. Thread the coupling halves together by hand to insure that the threads mate properly.
5. Tighten the coupling body hex nut and union nut with the proper size wrench until the coupling
bodies “bottom out” or until a definite resistance is felt.
6. Using a marker or pen, make a line lengthwise from the coupling union nut to the bulkhead.
7. Tighten the nuts an additional quarter-turn; the misalignment of the lines shows how much the
coupling has been tightened. This final quarter-turn is necessary to insure that the joint will not
leak. Refer to Table 9 for torque requirements.
Table 7 8-ton unit refrigerant charge
Evaporator
Model No.
Charge (ounces)
3-ton circuit 5-ton circuit
MMD96E 7 7
MMD95E 7 7
Condensing Units
Model No Charge (ounces)
MCD96A 361 581
MCD95A 361 581
MCD98W 54 94
MCD97W 54 94
Table 8 Line charges (field piping)*
O.D. Liquid Line Suction Line
1/2" 7.3 (1.1) 0.2 (0.1)
5/8" 11.7 (1.7) 0.3 (0.1)
7/8" 24.4 (3.6) 0.7 (0.1)
1-1/8" 41.6 (6.2) 1.2 (0.2)
*weight of R-22 in type “L” copper tube: lb per 100 ft (kg per 10 m)
NOTE
When hard piping is used, complete all piping and evacuate lines before
connecting quick connects.
Table 9 Refrigerant quick connect sizes and torque
Size O.D. Cu Coupling Size Torque (lb-ft)
3/8" #6 10-12
1/2" #10 35-45
7/8" #11 35-45
1-1/8" #12 50-65