Emerson ZX User Manual page 31

IMPORTANT - TO BE CLEARLY UNDERSTOOD PRIOR TO RUNNING ANY SCROLL
It is important to realize that the scroll compressor design requires system charging as
quickly as possible – with liquid refrigerant into the liquid line. This is to avoid running of
the compressor under conditions where by insufficient volume of suction gas is available to cool
not only the motor, but also the rotating scrolls. (Temperature builds up very quickly in the
DO NOT VAPOUR (GAS) CHARGE THE ZX SCROLL UNIT!
It is therefore follows that the Suction Service Valve must not be fully closed at any time when
the compressor is running. To do so would cause the compressor duress in the same manner
as explained above. This valve is provided for ease of connection and for the fitting of service
Step-by-Step:
•
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. At
this point it is all right to leave the crankcase heater off.
•
Connect the refrigerant cylinder to main service hose and purge line at the manifold end.
•
Then invert the refrigerant cylinder if necessary to ensure only 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.
•
The refrigerant cylinder should be weighed at this point to be able to record the final
refrigerant charge. Note that the standard receiver holds approximately 7.6kg of R22 (at
32C when it is 80% full )
•
Now open the liquid service valve (off the back seat). With a good vacuum in the system
the refrigerant cylinder inverted and at ambient you should not need to run the compressor
at all.
•
In colder ambient, it may be necessary to run the compressor in order to complete the
charging process. It is advisable to do this after the previous step, allowing the
system/bottle pressures to equalize and almost fully closing the receiver liquid outlet valve
(front seat).
•
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.
•
Turn off the unit and open the receiver outlet valve (which was almost fully closed earlier )
COMPRESSOR:
scrolls if this is not done !)
gauges without removing the unit panel.
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