68
EN/06.2016/i01 © STULZ S.p.A. – all rights reserved
WPA ExPlOrEr OrIGINAl INSTrUCTIONS
Description
Six months
One year
Five years
Air circuit
Clean the V-modules
Check the mounting, operation and balancing of fans
Water circuit
Clean the water filter
Check the level of the fluid to be cooled
Check the presence of air
Check and repair any leaks
Check and repair the fault insulation of pipes
Check the connections
Check the efficency of the differential pressure switch
Check the efficency of the flow swich (options)
Check the cleanliness of the evaporator water side
Electric circuit
Check for abnormal consumption
Check the tightness of all terminals
Check the cleanliness and integrity of the contatctors
Check the connections of the pressure switches
Unit in general
Check the absence of abnormal vibration
Check the absence of abnormal noise
The maintenance must be performed when necessary in order to ensure the smooth operation
of the chiller.
8.3 refrigerant Circuit
8.3.1 refrigerant charge
To be checked: sight glass, LP switch
An insufficient charge causes the formation of bubbles in the sight glass (in full load operation)
or in extreme cases the triggering of the LP switch. An operation with an insufficient refrigerant
quantity over a longer period leads to a reduction of cooling capacity and to high superheating
temperatures, which have a disadvantageous effect on the compressor lifetime.
If a leak is detected:
• evacuate all the refrigerant gas and dispose it according to the national regulation
• repair the leak
• do a pressure test by nitrogen
• extract the nitrogen by the vacuum pump (not by the compressor!) to approximately 0 barg
• fill with refrigerant gas according to name plate of the chiller for type and weight
INFOrMATION
R410A must be charged in a liquid state.