Vertiv Liebert CRV - Page 49

Charging Air-cooled Systems withLiebertLee-Temp Receiver
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.
To calculate the charge for the system:
1. Check the nameplate on the indoor unit for refrigerant type to be used. Unit control
configurations differ depending on refrigerant type.
2. The unit must be operating, refer to Checks to Perform after Start-up on page112.
3. Calculate the amount of charge for the system. See Refrigerant Charge Requirements for
Air-cooled Systems on page40.
4. Accurately weigh in as much of the system charge as possible before starting the unit.
5. Turn on unit disconnect switch, and operate the unit for 30 minutes using the charging
function in the "Diagnostic" menu of the Liebert iCOM control.
• A minimum 20psig (138kPa) must be established and maintained for the compressor to
operate.
• The charging function operates the compressor at full capacity and energizes the liquid-
line solenoid valve. The reheat and humidifier are disabled.
• The charging function can be reset as many times as required to complete unit charging.
6. Charge the unit until the liquid-line sight glass becomes clear. Then add an additional 1lb
(0.45kg) of refrigerant.
NOTE: A digital scroll compressor will have a clear sight glass only when operating at 100% capacity.
When operating below 100%, the sight glass may show bubbles with each 15-second unloading cycle.
Refrigerant-level Sight Glasses ontheLiebertLee-Temp Receiver
On the receiver at the condenser are 2refrigerant-level sight glasses. Refrigerant level will vary with
outside temperature. Check refrigerant level after the unit has been on for at least 15 minutes.
Sight Glass Levels at Outdoor Temperatures
• 40°F (4.5°C) and lower—bottom sight glass is 3/4 full
• 40 to 60°F (4.5 to 15.5°C)—bottom sight glass is full
• 60°F (15.5°C) and higher—top sight glass is 3/4 full
Vertiv | Liebert CRV Installer/User Guide | 49