NCF
23
EN
If the available space permits, in installations where the intake is connected to a pipe,
we recommend fitting a straight length of pipe with a length approximately 2.5 times the
diameter of the impeller, to guarantee correct air flow into the intake. See Figure 8.
With installations with an open air intake, we recommend leaving a distance equal to
approximately 1.5 times the diameter of the impeller between the fan intake and the
nearest wall or machine. See Figure 10.
4.5.3
Electrical connections
The fan’s power supply line must have a sufficiently high power rating.
Connection to the main power grid must only be carried out by qualified personnel. Also,
the client is responsible for the entire electrical system up to motor terminal board.
Remember the importance of installing a safe connection to earth for the fan. The earth
connection system must comply with legislation in effect in the country of installation and
must be periodically checked by qualified personnel. Make the connection to earth before
any other connection. Check that the connection layout is suited to the mains power
voltage.
Usually, standard electric motors can run in both directions indifferently. To invert the
direction of rotation, simply swap over any two power cables directly on the terminal
board.
The client must also install an electrical disconnecting device near the fan so that
maintenance personnel can have direct control over the power supply to the fan.
All work performed on the electrical system must only be carried out with the fan at rest
and electrically disconnected from the mains.
Before installing/starting up, ensure that the information on the identification plate on the
motor is compatible with the main power supply
4.5.4
Motor connections
See figures 2, 3 and 4. Check the data on the motor identification plate for which
connection to be used.
4.6
Connection to ducts
NOTE!
Installations with an open air intake are not recommended.
The fan must be connected to ducting with all parts correctly aligned, without obstructions
to air flow from gaskets or flexible components. The weight of ducting must not be
supported by the fan, and deformations of parts of the machine by ducting connections
must be avoided. Any flexible joints between the fan and intake and/or exit ducts must be
installed in a way that prevents stress on flexible components, and that avoids contacts
between metallic parts of the joints (see Figure 9).
4.7
Checks to be made before and after starting
4.7.1
Preliminary checks
WARNING!
Risk of personal injury!
Preliminary checks must only be performed with the fan at rest and disconnected from the
power supply.
Close off the air intake partially to reduce the power peak at start-up and the motor
starting time.