Stulz WDE Series, Руководство по эксплуатации

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WDE
44
EN/36B/08.2018 © STULZ SpA – all rights reserved
If a leak is detected:
• Let out the refrigerant in a collecting device down to a pressure of 1 bara;
• Connect a vacuum pump via a pressure gauge station on the high and low pressure side;
• Extract the refrigerant by the vacuum pump (not by the compressor!) to approx. 0 bara;
• Dispose the refrigerant according to the national regulations;
• Fill the circuit with nitrogen to 1 bara;
• Repair the leak;
• The circuit has to be run dry by several (at least 3x) fillings and extractions of nitrogen. When
necessary change the filter dryer;
• Fill with R407C.
ATTENTION
R407C must be charged in a liquid state.
After filling check the HP switch. An overfilling of the circuit makes the condensation pressure rise
and by that the power consumption of the compressor. In the extreme the HP switch triggers.
Sight glass and filter dryer
Bubbles in the sight glass indicate that the charge is insufficient or that the filter dryer is clogged. A
pollution of the filter dryer, whose origin task is to clear the refrigerant from impurities and humidity,
can be detected by a temperature difference upstream and downstream the filter dryer.
With too much humidity in the circuit, the expansion valve can freeze. In addition to this the POE oil in
the compressor, which comes in touch with the refrigerant, takes up humidity and loses its ability to
lubricate. In this case the refrigerant must be completely evacuated and recharged according to the
above described evacuation instruction.
Compressor
In the compressor there is a polyester (POE) oil charge, which does not have to be renewed under
normal operation conditions and holds out for the unit’s lifetime. However, it is possible that the
oil, as it reacts hygroscopically, has taken up humidity of the air after repeated recharging of the
refrigerant circuit due to repair works. The interaction between POE oil and water results in the
formation of acid. Owing to hyper acidity, corrosive processes take place inside the compressor. The
oil level can be checked by looking at the sight glass of the compressor.
DANGER
In case of topping up, use always the type of oil indicated on the technical data plate on the
compressor.
8.5. General appliance cleaning procedures
The metal casing of the unit can be cleaned using a detergent liquid as long as this liquid is
compatible with: PVC, polyethylene, silicone and polyester coating.
ATTENTION
Use of an unsuitable detergent might cause damage to the unit.
Do not use either acid or caustic substances or solvents like benzine to clean any part of the unit.
Use a vacuum cleaner to remove dust. Inner parts must be cleaned with a liquid detergent and air
at a pressure not higher than 4 bar and with the unit suitably connected to ground. Check also that
water pipes are firm: vibrations might cause leakages. Finally, check pipe insulation.