Piping and Filling with Refrigerant: R-134a and R-407c Circuits
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2.7 Filling the Direct Expansion (DX) Circuit—R-407c
Any recommended volumes will be approximate. The user must verify that all circuits of the system
have been adequately filled.
For Air Cooled Lee-Temp / Flood Back Head Pressure Control Units Only
1. Make sure the Liebert XDC is Off.
2. Connect the refrigerant gauge charging hose to the refrigerant drum and to the receiver at the
rotalock valve and/or to the Schrader valves on the liquid lines.
3. Weigh in the calculated charge based on Tables 14,15,16 and 17—values are maximum, based
on outdoor air temperature of -30°F (-34°C).
4. Open the rotalock valve and fill the complete calculated charge.
NOTE
If necessary, refer to 3.0 - Installation Checklist to ensure that the system has been properly
checked out and is ready to be filled with coolant.
NOTE
Proper safety equipment and proper refrigeration tools are required. Check unit nameplate for
correct refrigerant type before topping off or recharging a system.
NOTE
Refrigerant R-407c is a blend of three components, and must be introduced and charged from
the cylinder only as a liquid.
Refrigerant R-407c uses a POE (polyolester) lubricant. Do not open the compressor unit piping
to the atmosphere for more than 15 minutes. The compressors contain POE oil that is very
hygroscopic; it quickly absorbs water from the atmosphere. The longer the compressor piping is
left open to the atmosphere, the harder it will be to fully evacuate. If left open too long, the POE
oil may need to be replaced before achieving the required vacuum level.
Table 14 Indoor unit refrigerant charge—R-407c
Model 50/60 Hz Charge/Circuit, lb. (kg)
Liebert XDC160 17.5 (8.0)
Table 15 Outdoor air condenser charge—R-407c
Outdoor Ambient, °F (°C Model 50/60 Hz Charge / Circuit, lb (kg)
-30 to 95 (-34 to 35) CDL830 or CSL415 200 (90.8)
-30 to 100 (-34 to 38) CDL830 or CSL415 200 (90.8)
-30 to 105 (-34 to 41) CSL616 254 (115.2)
35 to 105 (2 to 41) CSL616 164 (74.5)
Table 16 Air cooled systems - liquid line charge - R-407c refrigerant per 100 ft (30 m) of Type "L"
copper tube
O.D., inches Liquid Line, lb (kg) Hot Gas Line, lb (kg)
3/8 3.7 (1.7) -
1/2 6.9 (3.1) -
5/8 11.0 (5.0 2.2 (1.0)
3/4 15.7 (7.1) 3.1 (1.4)
7/8 23.0 (10.4) 4.5 (2.0)
1-1/8 39.3 (17.8) 7.8 (3.5)
1-3/8 59.8 (27.1 11.8 (5.4)
1-5/8 - 16.7 (7.6)
Table 17 Indoor water/glycol cooled module – R-407C refrigerant charge
Model 60 Hz Charge / Circuit, lb(kg)
Liebert XDC 160 30.0 (13.2) per circuit