Charging Fin/Tube Condenser With Variable Fan Speed Control - Emerson Liebert CRV User Manual

6.8

Charging Fin/Tube Condenser with Variable Fan Speed Control

The system must be fully piped and evacuated before it can be charged. See 6.6 Vacuum and
Refrigerant Charge.
1. Check unit nameplate for refrigerant type to be used. Unit control configurations differ depending
on refrigerant type.
2. Charging the system with refrigerant requires the unit to be in an operational state.
3. Calculate the amount of charge for the system. Refer to the unit, condenser and refrigerant line
charge data in Tables 18, 19 and 21.
4. Weigh in as much of the system charge as possible before starting the unit.
NOTICE
Risk of improper refrigerant charging. Can cause equipment damage.
Refrigerant R-410A is a blend of two components 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. Emerson recommends 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.
5. Turn On unit disconnect switch. Operate the unit for 30 minutes using the charging function in
the diagnostic section of the Liebert iCOM
operates the compressor at full capacity and energizes the blower motor and the liquid line
solenoid valve. The reheat and humidifier are disabled. A minimum 20psig (138kPa) must be
established and maintained for the compressor to operate. 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 one additional pound
(2.2kg) 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.
7. As head pressure builds, the variable fan speed controlled condenser fan begins rotating. The fan
will run at full speed when sufficient head pressure is developed—fan starts to rotate at 310psig
(2137kPa) and is full speed at 400psig (2758kPa).
Refrigerant Connections for Air-Cooled Units
® control (see Figure 91). The charging function
49
® ™
Liebert CRV