Vertiv Liebert XDC User Manual

6. After completion of leak testing, release the test pressure (per local code) and connect to
vacuum pump(s) at the Schrader valves on the liquid lines and on the hot gas lines.
NOTE: There is a check valve in the discharge line and Liebert Lee-Temp piping assembly of each
circuit. Ensure that all pressure has been relieved before starting the vacuum pump.
7. Place a jumper hose from the service valve fitting on the outlet of the receiver and the
schrader fitting on the discharge header of the condenser. Front-seat the service valve two (2)
turns.
8. After 4 hours of pulling a deep vacuum, check the vacuum levels and, if they have not
changed, break the vacuum with dry nitrogen.
9. Pull a second and third vacuum to 500 microns or less. Recheck the vacuum level after 2 hours.
10. Once a system has achieved 500 microns, turn off evacuation, close the receiver service valve
and remove the jumper hose.
4.8 Filling the Direct Expansion (DX) Circuit—R-407C
NOTE: If necessary, refer to Installation Checklist on page59 to ensure that the system has been
properly checked out and is ready to be filled with refrigerant.
Any recommended volumes will be approximate. The user must verify that all circuits of the system
have been adequately filled.
For Air-Cooled Liebert Lee-Temp / Flood Back Head Pressure Control Units Only
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.
Refrigerant charging requires unit operation. Refer to Checklist for Liebert XDC Startup on page111.
1. Calculate the amount of charge for the R-407C side of the system. Refer to Table 4.13 on the
next page, Table 4.14 on the next page, Table 4.15 on page57 and Figure 4.13 on page57.
2. Weigh in as much of the calculated R-407C charge as possible by utilizing tank heaters on the
refrigerant bottles before starting the unit.
NOTICE
Risk of improper operation. Can cause equipment damage.
Before proceeding to step Turn Off the main power to the unit. below, the R-134A side must be
charged with the calculated refrigerant charge.
There also must be enough room heat to start the system the system (64kW minimum). If not,
running the compressors alone could cause the heat exchanger to freeze and burst.
3. Turn Off the main power to the unit.
4. Disconnect either the low-voltage wires from the #2 compressor contactors holding coils or
remove the high-voltage fuses for the #2 compressor bank.
Vertiv | Liebert® XDC™ User Manual | 55

Vertiv Liebert XDC Specifications

General

Brand	Vertiv
Model	Liebert XDC
Category	Freezer
Language	English