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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.
Access to the outdoor unit from the fans
For some maintenance tasks, it may be convenient to access
the outdoor unit by lifting the cover with the fan(s) (depending on
the model).
First, the power supply to the fan must
be disconnected.
Each fan features two quick-release
connectors (power and control) inside
the compressor box.
Then, the cover must be unscrewed.
This is fi xed to the machine using M6
Allen screws.
Ring screws (not supplied with the unit) are to be fi xed to the M10
hex nuts existing on the cover. The lifting slings will be hooked to
these ring screws.
- Lid with 1 fan (weight 78 kg): 3 nuts.
- Lid with 2 fans (weight 145 kg): 4 nuts.
Important: These nuts are only intended to lift the cover.
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 pressostat. This pressostat comes from the factory
adjusted to the nominal airfl 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):
■ 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.
Flow control
pressostat
33
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