Operation of the fan Operating manual - Fan CF-C
54 of 84 www.elektror.com 2004930 10.19/0.2
EN
8.5 Emergency shutdown of the fan
If a fan is installed in a ventilation system, operated in part or fully automatically, the
emergency shutdown of the fan installation is not a proble
m.
The fan is not equipped with an emergency stop or trip system. Shutting down the fan in the
event of failure should be done through the control system. The correct implementation of the
control system is the responsibility of
If the fan is equipped wit
h monitoring systems, the emergency shutdown will occur if certain
Following are the possible monitoring parameters:
Bearing temperatures
Bearing vibration
Condition of rolling bearings
Wear of rolling bearings
Rotational speed (fan and electric motor)
Direction of rotation
− Temperature of the conveyed medium
The following limit values can be distinguished:
-
Pre-alarm
Possible further operation of the fan only possible under uninterrupted supervision.
Main alarm
the fan.
-alarm and shut-down, please refer to the contents of the chapter 11.2
"Limit values
of vibrations" 3 "Bearing temperature limits").
8.6 Automatic operation of the fan
8.6.1 Rotational speed control by means of a frequency converter
During automatic fan operation, the fan shaft speed should not fluctuate by a preset value
(periodic adjustment). Fluctuation leads to damage on the drive side.
In addition, it is necessary to secure the correct time of
fan start-up to achieve the appropriate rotational speed or maximum speed
lowering the speed to standstill
changing the operating point and thus the rotational speed of the fan.
In order to avoid too high loads, in particular acceleration and braking in a short time, the
speed control by means of
a frequency converter requires, if possible, a high "inertia" setting.
In this way it is possible to maintain the phenomenon of fatigue of the impeller, shaft, clutch
etc. at a low level. The following indications allow to maintain as little as possible the additional
load on the shaft, caused by control procedures that affect the drive elements.
The ramp time is valid, its crossing is not allowed.
Regardless of the above, appropriate boundary conditions for a particular application case
should be taken
into account (moment of inertia of the impeller and drive system, acceleration
of the motor, current draw, adjustment procedures according to the needs of the process,
etc.).
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