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MVA 02 rev 5 - December 2017
If ignored, vibrations can:
cause the formation of cracks serious enough to cause structural failure, which may even be sudden
cause difficult operating conditions for bearings, with malfunctions that may even include seizing (with
dangerous overheating effects)
cause slackening of tightening and fixing components (nuts and bolts)
generate greater noise.
FVI
strongly recommends the use of a control and monitoring system for the fan, with continuous monitoring
of vibrations and bearing temperatures.
Depending on the specific application and use of the fan, it is advisable to define an "alarm threshold" for fan
vibration levels and bearing operating temperatures.
The monitoring of vibrations and temperatures makes it easier to take preventive actions
against accidents.
3.8.5
Operating speed risks
Operating speeds greater than those envisaged by the fan design can create conditions of risk due to the
reduction of the operative lifespan of moving parts.
In case of faults or malfunctions, overspeed conditions may be created due to:
Errors in the control logic system
Short circuits on monitoring components
Driver or inverter malfunctions
Mechanical breakage of components, and in particular on encoder shafts.
CAUTION:
Do not exceed the maximum rotation speed indicated by FVI.
Do not use ON-OFF operating cycles unless expressly approved by FVI.
Do not use variable-speed cycles unless expressly approved by FVI.
Do not subject the fan to thermal gradients greater than 3°C/minute.
CAUTION:
A condition of overspeed, even for a limited time, may cause irreversible damage and create
situations of extreme risk hazards.
During normal operation, conditions of overspeed attributable to the drive system or motor may occur, in
particular if the fan is supplied "with shaft only" or with motor "without drive system".
In these cases, it is the responsibility of the user to verify and guarantee the correctness of additional
installations.
The construction of the transmission by the user or installer is a critical point for safety.
The transmission is an integral part of the machine, and its construction requires a design process and
awareness of the design parameters developed by
FVI
.
