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Installation
18
2.5.4 Installation of Piping to Units
Use caution when connecting the quick-connect fittings. Read through the following steps before mak-
ing 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 refrigeration grade oil.
4. Thread the coupling halves together by hand to ensure that the threads mate properly.
5. Tighten the coupling body hex nut and union nut with the proper sized wrench until the coupling
bodies bottom out or until you feel a definite resistance.
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 ensure that the joint will not
leak. Refer to Table 10 for torque requirements.
8. Add liquid refrigerant charge for any field-fabricated piping (refer to Table 11) and the 5-ton
Liebert Challenger evaporator if used (refer to Table 12).
2.5.5 R-407C PFH Installed as a Replacement Condensing Unit in an R-22 System
When replacing the condensing unit of an existing Liebert split system containing R-22 and mineral
oil, the following should be considered.
1. Check for proper operation of the system prior to replacing the outdoor unit. If this is not possible,
at minimum perform a leak check to ensure that the components that remain (line set,
evaporator) are leak tight.
2. Check for acid or contaminants in the mineral oil.
NOTE
When using hard piping, complete all piping and evacuate the lines before connecting
quick-connects.
NOTE
Liebert Challenger 5-ton evaporator includes a nitrogen holding charge only. This holding
charge must be evacuated and unit placed in a 250 micron vacuum prior to connecting piping.
See Table 12 for field charge required.
Table 10 Piping connection sizes and torque
Line Size OD Cu Coupling Size Torque, lb-ft. (N-m)
1/4 or 3/8 #6 10-12 (145-175)
5/8 thru 7/8 #10 or #11 35-45 (510-655)
1-1/8 #12 50-65 (730-950)
Table 11 Line charges - refrigerant per 100 ft. (30m) of Type L copper tube
Line Size,
O.D., in.
R-407C, lb/100 ft. (kg/30m)
Liquid Line Suction Line
3/8 3.7 (1.7) —
1/2 6.9 (3.1) —
5/8 11.0 (5.0 0.4 (0.2)
3/4 15.7 (7.1) 0.6 (0.3)
7/8 23.0 (10.4) 1.0 (0.4)
1-1/8 — 1.7 (0.7)
1-3/8 — 2.7 (1.1)