Liebert XDC Piping Installation Method, Piping Installation-R-134a Pumped Circuit, Piping Mains

Piping and Filling with Refrigerant: R-134a and R-407c Circuits

Figure 19 Liebert XD system diagram

Liebert XDP/ Liebert XDC

					All supply and return
					mains must be level
Liebert XD	Liebert XD	Liebert XD	Liebert XD	Liebert XD	with or above the top
					of all Liebert
Cooling	Cooling	Cooling	Cooling	Cooling
Modules	Modules	Modules	Modules	Modules	XD modules

SLOPE—The main supply and return lines to and from the Liebert XDC must be sloped downward toward the Liebert XDC at a rate of 1-2" for every 20 feet (25.4-51mm per 6m) of pipe run. Horizontal connector lines should also be sloped downward from the cooling modules toward the main supply and return lines.

2.4Piping Installation Method

The assembly and connection means used for piping in the Liebert XD system are similar to those used for conventional refrigeration systems. All piping should be installed with high-temperature brazed joints. Soft soldering is not recommended.

During brazing, the lines must be filled with flowing dry nitrogen to prevent excessive oxidation and scale formation inside the piping. Prevailing good refrigeration practices must be employed for piping supports, leak testing, dehydration and charging. Failure to use good system practices may result in damage to the system. Refer to the ASHRAE refrigeration handbook for general good-practice refrigeration piping.

Insulate all piping lines to prevent condensation in applications where the dew point approaches the R-134a refrigerant temperature.

Liebert highly recommends venting the pressure relief valves for both the R-134a and R-407c sides out- side the conditioned space where it is open to the atmosphere. The R-134a side relief valve is inside the XDC unit at the top of the receiver. The R-407c water/glycol cooled side relief valves are located at each condenser beneath the XDC unit in the floor stand. The R-407c air cooled relief valves are located outside within the air cooled system.

2.4.1Piping Installation—R-134a Pumped Circuit

Liebert highly recommends venting the relief pressure of the Liebert XDC (located at the top of the receiver) outside of the conditioned space where it is open to the atmosphere.

Piping Mains

All refrigeration piping mains connected to the Liebert XD cooling module, both supply and return, should be installed with a downward pitch toward the Liebert XDC of 1-2" for every 20 feet (25.4-51mm per 6m) of pipe run.

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