Emerson 3000 User Manual

Page of 88
Air-Cooled Models—Self-Contained Compressor
29
Liebert
®
 Challenger 3000
Variable Fan Speed Charging
1. Check unit nameplate for refrigerant type to be used. Unit control configurations differ depending 
on refrigerant type.
2. Refrigerant charging requires unit operation. Refer to 2.9 - Checklist for Completed 
3. Calculate the amount of charge for the system. Refer to the unit, condenser and refrigerant line 
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 R407C is a blend of three 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 for 
the system 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 190 psig 
(1310 kPA) and is full speed at 250 psig (1724 kPA).
Table 10
Fan speed suction pressure transducer settings
Function
R-407C
Gauge (Sea Level)
Absolute
psiG (kPa)
psiA (kPa)
Pump-Down Cutout
20 (138)
35 (241)
Pump-Down Reset
65 (448)
80 (552)
Minimum to Start-Cooling
35 (241)
50 (344)
Low-Pressure Cutout (DX only)
52 (358)
67 (461)
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.