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4. START-UP
4.1 Preliminary checks
Prior to starting-up the cooling plant, previously filled with water, perform the following operations and checks:
1)
Operate the fan and check that it rotates in the direction such that the air enters via the lower openings and
leaves through the top cylindrical opening.
If this does not happen, stop the fan, then change the direction of rotation of the motor, swapping over the
positions of two of the three phases.
The direction of rotation of the fans should in any case be checked every time that repairs are made to, or
maintenance is performed on the electric motors and their control system.
Ensure that the protective grille is well anchored to the fan-cylinder and that there are no abnormal vibrations of
the unit as a whole.
2)
Operate the water circulating pump and check:
-
the spray-jet of the nozzles, which must be directed vertically downwards, with a well-open cone and of equal
intensity for all the nozzles.
-
the whole spray pattern, which should completely and uniformly cover the upper surface of the filling material
in such a manner as to provide a uniform rain pattern falling from the underside of the fill
-
the water-tightness of the flanged and threaded connection joints and of the related gaskets
-
the head pressure, in meters of water gauge, indicated by the glycerine hydrometer. It should be borne in
mind that it is necessary that the value read does correspond to that indicated on the identification plate that is
to be found on the side of the unit: otherwise, it means that the water flowrate of the circuit is different from the
design value for which the cooling tower was sized.
3)
Operate
simultaneously
the fan and the water recirculating pump, checking carefully the absorbed currents
of the related motors and ensure that the values measured do not exceed those indicated on their respective
data plates.