Stulz WDE Series, Operating Instructions Manual

Page: 42 / 57

WDE
42
EN/36B/08.2018 © STULZ SpA – all rights reserved
8.2. Preventive maintenance schedule
Interval Operation
Every month • CONDENSATE DRAIN: check that the condensate drain system is perfectly clean and efficient.
• HEAT EXCHANGERS: check that the heat exchangers are efficient and not clogged or dirty.
• AIR FILTERS: check the condition of the filters and replace them if necessary (dirty filter alarm).
• FANS: check that fans do not show signs of overheating or abnormal vibrations and that they are free to rotate.
Every 6 months • REFRIGERANT CIRCUIT: sight glass.
• REFRIGERANT CHARGE: check that the system is properly filled. If it is not filled then search for the leak (check
joints in particular), repair it and refill the system.
• FREE COOLING DAMPER (when present): check tightness of fixation of air deflector to the shaft.
Every year • SAFETY DEVICES OF REFRIGERANT CIRCUIT: high pressure switch.
• COMPRESSOR: check the oil level from the indicator on the compressor.
• ELECTRIC CIRCUIT: check that electric connections are tight, that switches, remote control switches and isolating
switches are operating and in good condition. Also check that the control board operates and perform a test of
alarm signals.
• MECHANICAL PARTS: clean the inner components of the system.
ATTENTION
If air conditioner works in particularly dirty environment or if experience shows that a more
frequent maintenance is needed, this must be made as necessary.
8.3. Air circuit
Heat exchangers
Blow compressed air through the heat exchanger in the opposite direction to that of the air flow
during normal operation. Please take care to avoid contamination of the aluminium surface with
reactive dust, chemical elements, other metal particles and ions.
ATTENTION
Do not distort the fins while cleaning, this also increases the air resistance.
Fans
The bearings of the fans are lifetime lubricated and do not need maintenance. Check the operation
current. An increased operation current indicates either a higher air resistance by a clogged pre-
filter or a winding short circuit in the fan motor. Fans are automatically controlled with variable speed.
To make measurements at nominal speed, use manual control.
Air filters
A differential pressure switch monitors air intake filter. As soon as pressure loss exceeds an adjustable
value, a dirty filter alarm is enabled by the electronic controller. In this case, filter replacement is
necessary.