Liebert 50 & 60Hz User Manual

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.

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.

MMD96E

7

7

MMD95E

7

7

MCD96A

361

581

MCD95A

361

581

MCD98W

54

94

MCD97W

54

94

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)

3/8"

#6

10-12

1/2"

#10

35-45

7/8"

#11

35-45

1-1/8"

#12

50-65