Alfa Laval S 821 - Page 157

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8 TECHNICAL REFERENCE 8.4 INTERFACE DESCRIPTION
The vibration level shall be high for 3 seconds
to generate an alarm. The first level is only
used to generate an alarm while the second
level shall stop the machine.
The vibration monitor shall include self check
function to be performed at least at initiation of
STARTING.
If vibrations exceed the second alarm level the
separator shall be stopped the quickest way
possible and it shall not been restarted until
the reasons for the unbalance have been found
and measures to remove them have been taken.
Signal processing in STARTING:
If vibrations exceed the second alarm level the
separator shall be stopped automatically by
SAFETY STOP.
If the self check system triggers, an alarm shall
be given and an automatic stop by NORMAL
STOP shall be initiated.
Signal processing in RUNNING:
• If vibrations exceed the first alarm level an
alarm should be given. Vibrations of this
magnitude will reduce the expected life time
of the bearings and should therefore be
eliminated.
• If vibrations exceed the second alarm level
the separator shall be stopped automatically
by SAFETY STOP.
• If the self check system triggers, an alarm
shall be given.
Signal processing in STOPPING:
• If the self check system triggers, an alarm
shall be given.
Signal processing in NORMAL STOP:
• If vibrations exceed the second level the
system shall turn over automatically to
SAFETY STOP.