6.After four hours, check the pressure readings and, if they have not changed, break vacuum with dry nitrogen. Pull a second and third vacuum to 250 microns or less. Recheck the pressure after two hours.
7.Remove the jumper hose installed previously from between the service valve fitting and the condenser. After completing this step, proceed to
Lee-Temp 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 Installation.
3.Calculate the amount of charge for the system. Refer to the unit, condenser and refrigerant line charge data in Tables 6, 7, 8 and 9.
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 the system in the diagnostic section of the Liebert iCOM control. The charging function operates the compressor at full capacity and energizes the blower motor and liquid line solenoid valve. The reheat and humidifier are disabled. A minimum 20psig (138kPa) must established and maintained for the compressor to operate. The charging function can be reset as many times as required to complete unit charging.
Table 11
|
| ||
|
|
|
|
| Gauge Reading |
|
|
| (Sea Level) |
| Absolute |
Function | psiG (kPa) |
| psiA (kPa) |
|
|
|
|
20 (138) |
| 35 (241) | |
65 (448) |
| 80 (552) | |
Minimum to | 50 (345) |
| 65 (448) |
52 (358) |
| 67 (461) | |
6.Charge the unit until the liquid line sight glass becomes clear. Then add one additional pound (2.2 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
Lee-Temp Receiver Refrigerant Level
On each receiver at the condenser are two
Sight Glass Levels
40°F (4.5°C) and
32
