Table 54 Fan Speed Suction Pressure Transducer Settings - Emerson Liebert DS Series User Manual

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 11.0 - Checklist for Completed
Installation.
3. Calculate the amount of charge for the system. Refer to the unit, condenser and refrigerant line
charge data in Tables 50, 51 and 52.
4. Weigh in as much of the system charge as possible before starting the unit.
CAUTION
!
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
System #1 and System #2 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.
Table 54 Fan speed suction pressure transducer settings
Function
Pump-Down Cutout
Pump-Down Reset
Minimum to Start-Cooling
Low-Pressure Cutout
Freeze Protection (DX w/Econ-O-Coil)
Due to control processing time, the pumpdown pressure at compressor shutoff will be approximately
20psiG (138kPa) / 35psiA (241 kPa) even though the setpoint is 35 psiG (241 kPa) / 50 psiA (344kPa).
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 190 psig
(1310 kPA) and is full speed at 250 psig (1724 kPA).
R-22
Gauge (Sea Level) Absolute
psiG (kPa) psiA (kPa)
35 (241) 50 (344)
65 (448) 80 (552)
35 (241) 50 (344)
20 (138) 35 (241)
48 (331) 63 (434)
90
R-407C
Gauge (Sea Level) Absolute
psiG (kPa) psiA (kPa)
35 (241) 50 (345)
65 (448) 80 (552)
35 (241) 50 (344)
20 (138) 35 (241)
52 (358) 67 (461)
Piping