Vertiv Liebert DA250 Installer/User Manual page 39

Charging DA265 Air Cooled Systems (Liebert® DA265 without Receivers)
NOTICE
Risk of improper refrigerant charging. Can cause equipment damage.
R-410A is a blended refrigerant and must be introduced and charged from the cylinder only as a liquid.
When adding liquid refrigerant to an operating system, it may be necessary to add the refrigerant through the
compressor suction service valve. Care must be exercised to avoid damage to the compressor. We recommend
connecting a sight glass between the charging hose and the compressor suction service valve. This will permit
adjustment of the cylinder hand valve so that liquid can leave the cylinder while allowing vapor to enter the
compressor.
NOTICE
Risk of improper operation. Can cause compressor failure.
Operating the unit with the EEV closed can cause compressor failure. The reheat and humidifier are disabled. A
minimum of 20 psig (138 kPa) must be established and maintained for the compressor to operate. The
charging function can be reset as many times as required to complete.
To charge the system:
1. Check the nameplate on the indoor unit for the refrigerant type to be used. Unit control configurations differ
depending upon the refrigerant type.
2. The unit must be operating during charging. Refer to
3. Calculate the amount of charge for the system. See
on page 29.
4. Accurately weigh in as much of the system charge as possible before starting the unit. Do not exceed the
calculated charge by more than 0.5 lb (0.37 kg).
5. Close the Liebert® MCV heat rejection skid disconnect switch.
• Unit must be charged with the return air within +/- 10°F (5.5° C) of the operating point.
• If the operating point changes, the charge may need to be adjusted according to the new operating
point.
• The return air temperature to the unit being charged must be stable. If this is not possible due to the lack
of heat load, then the load banks must be used to offset the cooling load during startup.
6. Close the Liebert® DSE disconnect switch.
7. In the Service menu of the Liebert® iCOM™ controller, select Diagnostics/Service > Diagnostics.
a. Enable Manual Mode.
NOTE: Manual mode will time out after 30 minutes.
b. In the Search Box type E177 and press Enter.
Two parameters appear in the Parameter Directory (E177.1 and E177.2).
Press the Gear icon in the upper right corner.
Select Make Writeable.
Change E177.1 and E177.2 from 15 minutes to 2 minutes.
This will reduce the superheat setpoint from 24°F (13.3° C) to 13°F (7.2° C) degrees in two minutes.
6 Piping and Refrigerant Requirements
Checklist for Completed Installation
Refrigerant Charge Requirements for Air Cooled Systems
on page 37
35