Commissioning; Adding The Refrigerant; Packing; Vacuuming The System - Vertiv Liebert LPC Series User Manual

3 Commissioning

3.1 Adding the Refrigerant

3.1.1

Packing

Before packing the unit, high pressure nitrogen gas is filled in the unit at a pressure of 25 bar.
With a dwell time of not less than 12 hours, the recorded holding pressure should be same
before and after this activity is completed.
3.1.2

Vacuuming the system

When the nitrogen gas is to be evacuated from the system, the ball valve from the indoor unit
should be opened simultaneously with the needle valve from the rear side of the electronic
expansion valve and the compressor discharge line respectively.
For longer refrigerant piping distances, a replacement operation is required, i.e. a pressure
lower than 20 Pa (absolute pressure) is to be maintained to add a small amount of refrigerant
charge into the system till the nitrogen evacuation process is complete. This may cause a
pressure below 20pa maintained for a considerable amount of time. Upon completion of the
evacuation process and charging the refrigerant to the desired pressure, the sight glass is
indicated green.
Engineering Standards propose an evacuation time of 4 hours. However, the same needs to
be adjusted according to the situation based on the refrigerant piping requirements at site.
3.1.3

Service tools operation on the controller

After completing the vacuuming process, the LPC background service tooling needs to be
accessed and in the manual control mode, the menu displays the system as evacuated, refer
figure 3-1. Manual mode enable is selected and Mode selection is controlled evacuation.
3.1.4

Manual operation for evacuation mode

If evacuation mode is not getting activated, the background service tooling menu needs to
be checked to ensure that the line solenoid valve and electronic expansion valve in an open
state along with high and low pressure setting of the needle deactivated simultaneously to
Vertiv I Liebert LPC I User Manual
Figure 3-1
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