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- Evacuation
a.
After the system is leak checked, connect approved dual stage vacuum pump
sized to application with fresh oil to evacuation valve.
b. Ensure all inline system shut-off valves and solenoid valves are fully open.
c.
Evacuate the system to 300 microns.
d.
A triple evacuation is recommended. The third and final evacuation should
achieve a value of 300 microns or less. After this vacuum is reached, system is
ready for refrigerant charging and add as much refrigerant as possible into
the receiver.
- Charging and commissioning
Reminder
-
The scroll compressor design requires system charging with liquid refrigerant
into the liquid line.
-
Do not vapor charge the ZX Scroll unit. After ensuring all valves are opened
and system is vacuumed properly, only then start the refrigerant charging
process.
Step-by-step:
1.
Ensure that there is no power supply to the ZX unit. The Liquid Line solenoid
needs to be kept open for the charging process and this may require a
temporary power feed to it.
2. Connect the refrigerant cylinder to main service hose and purge line at the
manifold end.
3.
Ensure correct orientation of the refrigerant cylinder. Follow cylinder
labeling/instructions so that liquid refrigerant can be charged into the
system. This will be charged through the high-pressure side of the manifold
and ZX unit liquid service valve.
4.
Now open the liquid service valve (off the back seat). With a good vacuum in
the system, the refrigerant cylinder correct orientation and at ambient, you
should not need to run the compressor at all.
5.
The compressor can then be started, and the unit continued to be charged
(with liquid refrigerant through the liquid service valve). The quantity of
charge should always be measured. See note.
6.
Turn off the unit and open the receiver outlet valve (which was almost fully
closed earlier).
7.
The system needs to be operated down to its design evaporating
temperature before you can be sure the charge is correct. It is at this point
that the normal refrigeration operational checks can be carried out - such as
checking the liquid line sight glass for violent bubbles and the operating
pressures.
In the event that the system is still short of refrigerant, repeat from step #5
onwards.
Refrigerant charging is regarded full/complete when the operating
temperature of the system has been stable for some time and the liquid line
sight glass is clear.
