Operation And Control - CLIMAVENETA accurate ax Installation - User - Maintenance Manual

OPERATION AND CONTROL

WATER-COOLED UNITS
Water in an open circuit
If the temperature of the cooling water is not controlled and may fall
below 25°C, a pressure control valve is required (available as an
accessory) for each condenser; in this case, the supply pressure must
not be less than 200 kPa (2 bar).
IMPORTANT: for systems in which the water is cooled using a
cooling tower, make sure suitable filters are used, to prevent the
plate condensers from fouling quite quickly.
Remember that the units are supplied without the sys-
tem circulating pump.
Water in a closed circuit
The condensers on the units are supplied with water pumped in a
closed circuit and cooled by external radiators; check that the
cross-section of the pipes and that the characteristics of the cir-
culating pump are suitable: an insufficient water flow-rate affects
the performance of the air-conditioner. The temperature of the
cooling water must be controlled so as to not fall below 25°C,
preferably according to the diagram shown in the figure.
Remember that the units are supplied without the sys-
tem circulating pump.
IMPORTANT: the cooling water must contain a percentage
of ethylene glycol (passivated and consequently non-corro-
sive) according to the minimum expected outside tempera-
ture. In the Energy Saving models, the use of glycol is always
required.
CALIBRATING THE THERMOSTATIC VALVE
(air-cooled models)
The thermostatic valve is calibrated using the adjustment screw
shown in the figure; in the water-cooled models, the correct cali-
bration is already performed in the factory.
• Check that the subcooling of the liquid at the condenser outlet
is around 3-5°C;
• Check that the thermostatic valve superheating value is cor-
rect (around 5 °C);
• Check that the valve sensor bulb is correctly positioned,
secured and insulated.
If the superheating is above the value indicated previously, open
the valve further; if it is lower, close the valve further.
NOTE: the thermostatic valve must only be calibrated by
specialist personne
50 EN
25 °C
adjustment screw
ACCURATE AX - AW - AD - AT - AF