Emerson Liebert ICOM-DO Installation Manual download pdf (Page 43)

Refrigerant Connections

Variable Fan Speed Charging

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 17, 18 and 19.

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 control (see Liebert iCOM user manual, SL-18835).

The charging function 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.

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).

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.

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Emerson Liebert ICOM-DO Installation Manual Page 43