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© STULZ S.p.A. – all rights reserved EN/06.2016/i09
WSA ExplOrEr OriginAl inStructiOnS
8. Maintenance
8.1 Safety instructions
All maintenance work is to be carried out under strict compliance with the country-specific
accident prevention regulations. In particular we refer to the accident prevention regulations for
electrical installations, refrigerating machines and equipment. Non-compliance with the safety
instructions can endanger people and the environment.
Maintenance work is only to be carried out on the units by authorized and qualified specialist
staff.
WArning
Work on the system must always only be carried out when it is shut down. To do this, the unit
must be switched off at the controller and at the master switch. A "DO NOT SWITCH ON"
warning sign must be displayed.
DAngEr
In case of VSD compressors, wait five minutes after the OFF position of the main switch
before start doing any operation in the electrical cabinet. (Discharges of the capacitors)
Live electrical components are to be switched to de-energized and checked to ensure that they
are in the de-energized state.
Some verifications must be effected with the unit in operation (measuring the current, pressures,
temperatures). In such a case the unit must only be switched on at the master switch after all
mechanical connections have been carried out.
8.1.1 Warning notes
• When the master switch is turned ON and the controller is stopped the power contactors are
live, even if the components are not operating.
• At the fan contactors, dangerous voltages occur. Do not open the unit within the first 5 min-
utes after disconnection of all phases. Be sure that the unit is being isolated.
• The electronics housing of the fan motor can get hot.
• The fans have an overrun time after the unit is stopped. (Risk of injury)
8.2 Maintenance intervals
Description
Six month
One year
Five year
refrigerant circuit
Check the sigh glass
Oil level in of the compressors
Operation of the heaters on the compressor crankcases
