Fans And Air Ducts; Checks In The Axial Fans; Checks In The Ec Plug-Fans; Checks In The Centrifugal Fans (Optional) - Carrier 50FF Series Installation, Operation And Maintenance Instructions

9 - FANS AND AIR DUCTS

9.1 - Checks in the axial fans

■ Before commissioning, check the blade rotation direction and
that the axis turns without strokes nor vibrations.
■ Once running, check the operation conditions: pressures, fl ows
and consumptions.
■ With electronic fans (standard), check that they adapt their
rotational speed based on the condensation or evaporation
pressure.
Note: Optionally these units can be supplied with two-speed
fans.

9.2 - Checks in the EC plug-fans

■ Before commissioning, check the blade rotation direction and
that the axis turns without strokes nor vibrations.
■ Once running, check the operation conditions: pressures, fl ows
and consumptions.
■ The coupling of characteristic curves of the fan and the room
is very important, so that the fl ows and pressures provided to
the duct network are as required.
■ The variable-speed plug-fans, both supply and return, have a
fl ow control switch. This switch comes from the factory adjusted
to the nominal fl ow. However, the fl ow for diff erent conditions
can be readjusted on site from the graphic terminal (please
refer to the "50FC" control brochure).

9.3 - Checks in the centrifugal fans (optional)

If the unit is equipped with centrifugal return fans (available in BT
and BB assemblies):
28
Flow control switch
■ Before commissioning, check the blade rotation direction and
that the axis turns without strokes nor vibrations.
■ Once running, check the operation conditions: pressures, fl ows
and consumptions.
■ The overlapping of characteristic curves of the fan and the room
is very important, so that the fl ows and pressures provided to
the duct network are as required.
Pulley and belt calibration
Attention: Before performing these operations, it is
necessary to verify that the unit is disconnected from
mains.
The centrifugal motorfans are coupled through pulleys and belts.
In these fans, the following must be taken into consideration:
Pulley alignment:
■ The pulleys must be on the same plane, so it is important to
check them with the help of a ruler or a laser aligner.
■ In case they are not aligned, remove the pulley screws, and
after removing the taper pin, the set of pulley and taper can be
slided over the axis (this action can be performed both in the
motor as well as in the fan).
Pulleys must stay on the same plane
Tensor
screw
Pulley
screws
Taper pin