EN/10.2021/i04 © STULZ S.p.A. – all rights reserved
WLA CompACT - TRANSLATIoN oF oRIGINAL INSTRUCTIoNS
WLA CompACT - TRANSLATIoN oF oRIGINAL INSTRUCTIoNS
9.3.
Extraordinary maintenance
For information and quotations, contact the manufacturer technical support service.
Special maintenance operations include:
•
Repair or replacement of any unit component activated with electric motor; any intervention
on the refrigerant circuit that requires the charge to be restored, e.g. repair or replacement of
components,
•
Such as dehydrator filter, thermostatic valve, evaporator, condenser, and compressor..
9.3.1
Refrigerant refill
Every time a leak is detected or the refrigerant circuit must be opened to replace a components,
refill the refrigerant circuit.
Perform the following operations if a leak is detected or if the circuit must be opened to replace
a component.
1.
Collect the refrigerant in a collection device with pressure lower than 1 bar-a.
2.
Connect a vacuum pump via pressure gauge to the high and low pressure side.
3.
Remove the refrigerant from the vacuum pump (not from the compressor!) up to about 0 bar-a.
4.
Dispose of the refrigerant according to national standards.
5. Fill the circuit with nitrogen at 1 bar-a.
6. Repair the leak.
7.
Eliminate the humidity from the circuit with at least 3 filling and nitrogen extractions. When
required, replace the dehydrator filter.
8. Once the circuit is closed, make sure to create the vacuum with a specific pump for a sufficient
period of time. On this purpose, check that the absolute pressure has reached at least 0.1 bar-a
with the pressure gauge. Make sure that upon switching the vacuum pump off, this pressure
does not increase (its increase may indicate that the welding has not been made correctly)
9. Refill with R134a liquid using the compressor intake connection. The amount of refrigerant to
be refilled is equal to that indicated on the chiller data plate.
WARNING
To prevent the compressor from suctioning great amounts of liquid, we recommend opening
the chiller cylinder valve for 10 s, close it and wait 1 minute before opening it again.
9.3.2 Compressor oil top up
For replacement or top up operations, use the top up inlet on the compressor, which consists of
a Schrader valve.
WARNING
The type of oil to be used must have equal characteristics to those indicated on the compressor
data place or contact the Service.
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