© STULZ S.p.A. – all rights reserved IT/10.2021/i04
WLA CompACT - TRANSLATIoN oF oRIGINAL INSTRUCTIoNS
WARNING
To use the chiller with 460V/3/60Hz three-phase power supply, modify the electrical
connection of the winding secondary transformer. See the electrical diagram shown in
“MANUAL PART II” for the modifications to be applied.
As default setting, the digital inputs for any customer’s device (e.g. remote ON-OFF control)
are disabled. If installed, inform the person in charge of commissioning about the necessity to
enable the corresponding digital inputs.
7.3.1 Check the sequence of the phases
INFoRmATIoN
This function is available only for chillers with three-phase power supply (400/3/50 or
460/3/60) and rotary compressor (WLA05 - 08 - 10 - 13)
Once you have closed the protection panels of the electric compartment, close the main
disconnecting switch by setting it to position I. If the sequence of the power supply phases is
incorrect, a phase is missing or voltage is too low, the compressor doesn’t starts.
The display doesn’t shows any alarm.
If within 30 second the compressors doesn’t start, check the sequence of the phases.
Check the phase voltage on all the power supply phases. If this is correct, the phase sequence
must be modified. Therefore, switch the connection of two phases of the power supply on the unit
terminals.
Once this operation is complete, make sure that the display shows the unit in OFF status and open
the main switch.
7.4.
Commissioning preliminary operations
The operations to be performed before commissioning must be carried out by the installers
according to their field of expertise. The commissioning preliminary operations must be performed
maximum two days before commissioning.
Check correct installation
Make sure that the unit has been installed as described in chapter “7. Installation”.
•
Make sure that the hydraulic connections are correct and comply with the indications of the
circuit inlet and outlet positioned near the chiller connectors.
•
Make sure that the refrigerant does not leak.
•
With the main disconnection switch open (position 0), access the electrical panel by opening
the covering panels.
•
Make sure that the power supply and earthing cables are connected firmly to the respective
terminals.
•
Make sure that the power supply voltage falls within the values allowed for the unit and stated
in paragraph 6.3.
•
Close the protection panels of the electrical panel and take the main disconnection switch of
the unit to I.
Low temperature operation
As indicated in paragraph 6.1, for chiller water supply temperatures lower than 10°C and external
air temperatures lower than 2.5°C, it is necessary to add an antifreeze liquid (ethylene glycol) to the
water to be cooled.
The percentage of antifreeze liquid must be established according to the project values for the unit
outlet water minimum temperature and for the external air minimum temperature, in compliance
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