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Warning :
Moving parts of unit and electric shock will cause serious injury or fatality
to human. Power supply to the unit must be disconnected before carrying
out any maintenance work.
a) Dirty filter will increase the air resistance, dirty heat exchanger will reduce the cooling capacity of the unit and
blocked drain pan will cause water dripping to the ceiling of the building. In view of that, schedule maintenance
should be carried out to clean the filters, heat exchanger and drain pan.
b) It is prohibited to operate the unit without any filter to prevent rapid blockage of heat exchanger by dust and as
a result, poor heat transfer. Thus, it is recommended to install filter at return air duct to maintain cleanliness of
aluminum fins for better and consistent heat exchange.
c) Water temperature during summer should not be lower than 5
°
C and not higher than 80
°
C during winter. The
water must be treated and ensure it is clean for optimum performance.
d) It is not recommended to adopt control that allows flowing of cool water through heat exchanger with fan motor
idle. This will cause extensive condensation occur not only on heat exchanger but on the surface of casing due
to very low air temperature in the unit. If the control do not prevent chilled water flowing through heat exchanger
during idling of fan motor, it is recommended to close the water circuit through manual hand valve.
e) When the unit is not going to be used for extended period, the water pipes and heat exchanger should be filled
with water to reduce internal corrosion. If the unit is going to be idle throughout the winter, the water pipe should
be drained completely and anti-freeze procedure should be adopted to prevent water pipes breakage.
Caution : Unfiltered and untreated water will cause excessive scaling, corrosion and growing of
bacteria.
Servicing and Maintenance
