Elektror CF Series - Natural Frequency of the Fan; Parameterisation of the Frequency Converter; Adjustment Range of Rotational Speed; Disturbances, Error Search and Troubleshooting

Operating manual - Fan CF-C Operation of the fan
2004930 10.19/0.2 www.elektror.com 55 of 84
EN
Table 15: Rate of change of the rotational speed (Frequency converter ramp time)
Fan rotation speed [min
-1
]
Ramp time [s]
750 38
1000 50
1200 60
1500 75
1800 90
3000 150
3600 180
8.6.2 Natural frequency of the fan
Each fan component (in particular the impeller) shows its own natural frequency excited by a
specific fan speed, in which case resonance is not excluded.
Fans are calculated and constructed in such a way that during operation at a constant rated
speed the resonance phenomenon does not occur.
The operation of a fan with speed control by means of
a frequency converter allows the
occurrence of excitation in any case the rotational speed (frequency) is being changed.
Additional excitation by the frequency converter is possible. If the component's own
frequencies are in the fan rotational speed range,
they require extinguishing due to the
appropriate parameterization of the frequency converter.
8.6.3 Parameterisation of the frequency converter
Where the fan is supplied with a frequency converter, the set parameter values must be
retained.
Any change in pa
rameter values leads to the loss of warranty rights. The possible effects of
changing parameter values or entering incorrect parameter values are listed below:
−
operation does not generate low vibrations according to ISO 14694 or DIN ISO 10816-3
−
fatigue cracking of the impeller
−
resonant vibrations of different components
−
destruction of the clutch and other drive components due to too fast start-up and braking as
well as changing the fan operating points.
8.6.4 Adjustment range of rotational speed
In order to maintain the bearing lubrication condition, the speed range of 1:10 should not be
exceeded. In particular, in the 5 Hz range of the output frequency of the frequency converter,
torsional vibrations of the drive may occur, which should be avoided.
8.7 Disturbances, error search and troubleshooting
In the case of damage that occurred during the warranty period, inform the manufacturer
immediately.
Before contacting the manufacturer, make a note of the data on the nameplate.
Disturbances and observations should
be presented as accurately as possible. The more
accurate the information, the faster and more accurate the manufacturer's help can be.
8.7.1 Searching for errors
The error search will determine the nature of the disturbance. If a malfunction occurs,