Nederman NCF, Instruction Manual, Page: 19 / 25

NCF
19
EN
4.5 Checks to be made before and after starting
4.5.1 Preliminary checks
WARNING! Risk of personal injury!
Preliminary checks must only be performed with the fan at rest and
disconnected from the power supply.
When starting the fan for the first time, the following preliminary checks are
necessary:
•
Check that all bolts are correctly tightened (rotor, supports, foundation
bolts, and transmission components).
•
Check the lubrication of the fan and motor bearings; if necessary,
regrease (see Chapter
5. Maintenance
).
• Check that all rotating parts can turn freely.
•
Check that there are not foreign objects inside the fan.
•
Check that the fan turns in the correct direction: power the motor for a
brief moment to see if it turns in correct direction indicated by the arrow
on the fan housing; if necessary, invert the direction of rotation (see
Section
4.4.3. Electrical connections
).
You may now start the fan. With centrifugal fans, close off the air intake
partially to reduce the power peak at start-up and the motor starting time.
4.5.2 Checks to be carried out with the fan running
Check that the power absorption does not exceed the value indicated on the
motor identification plate, if it does; stop the fan immediately and contact the
manufacturer.
The fan must run without excessive vibration and noise.
Check, with the fan at rest and at an outside air temperature of 20°C, that
the bearings do not exceed the maximum operating temperature (maximum
bearing temperature 70°C).
During the first few hours of operation, it is normal for the bearings to reach
slightly higher temperatures, as long as they later stabilise at a lower value.
In the event of overheating of the bearings, contact the Nederman technical
assistance department.
After 3 - 4 operating hours, with the fan at rest and disconnected from the
power supply, check again that all bolts are correctly tightened, the bearing
temperature.
4.6 Malfunctions anf causes
Table 4-1: Malfunctions and causes
Problem Reason Cause
Power absorption much
lower than nominal value
Insufficient air flow
•
Rotational speed too low.
•
Nozzle or tubing partially obstructed.
•
Fan rotor partially obstructed.
•
Pressure resistance offered by the system higher than the
design value.
•
Fluid density higher than the design value.
•
Inverted direction of rotation.