SystemAir MCV 15 Manuel D'installation page 18

 67$5783 352&('85( $1' &+(&./,67
The refrigerant load in air-cooled and split systems is a particularly important aspect in the correct
operation of the entire installation; it is therefore necessary this process be done by an expert
Refrigeration Contractor following the indications given in the previous pages. The system is to be
loaded only with the refrigerant gas indicated on the unit identification label.
 67$5783 2) )$1 6(&7,21
Check that the power, as prescribed by the system design, reaches terminals R-S-T, that the neutral is
wired to terminal N and that the circuit is adequately earthed.
If, temporarily, there is no requirement to operate the other parts of the air-conditioning system (which,
depending on the ambient conditions, could start-up automatically) disconnect the relevant interruptor
switches.
Push the 21 button if the unit is equipped with the microprocessor controller, and, if not, activate via
the switch on the front of the indoor unit, and in this way the fans will start.
1%
On the MCV and CD units the fan motors are almost always single phase and
therefore the direction of rotation is factory set. On other special units or MD units the fan motors are
three phase and therefore one has to check the correct directionof rotation. To see if a motor is single
or three phase it is sufficient to check the electrical diagrams supplied with the unit.
When belt drive fans are used, always check the tension of the belts and the alignment of the pulleys,
even if these are always checked during factrory tests (see the MAINTENANCE section).
7+( )$16 0867 127 %( $//2:(' 72 581 :,7+ 7+( 3$1(/ 23(1 )25 025(
7+$1  6(&21'6
Verify the input power of the electric fan motors, which must be contained within the values indicated
on the identification plate of the motors.
If the engaged power / current is higher because the external pressure drops have been
overestimated, then it is necessary to block part of the supply or return airflow, or even to block part of
the air passage on the fan mouth, in order to return within the limits indicated on the identification
label. Then, if a single phase fan-motor is fitted (MCV or CD), it is possible to adjust the airflow by
acting on a speed regulator (if fitted).
 67$5783 2) &2035(6625 6(&7,21
Close the interruptor switches opened during start-up of the fan section and check that all wiring is
tightly screwed into its terminal.
Set all the adjustments on the microprocessor control or, if not fitted, on the thermostats in order to
provoke the start-up of the compressor.
The compressors will only operate if ambient conditions exceed the limits set on the temperature
control of the indoor unit.
16