Bently Nevada 3300/48, Operation Manual

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Case Expansion Monitor Operation
84417-01
4 MONITOR FUNCTIONS [CONT]
BUFFERED OUTPUT - The Case Expansion
Monitor provides the buffered output from the
LVDTs at two locations: a t the coaxial cable
connectors on the front panel and at the
terminals on the Signal Input Relay Module.
These connectors can be used to connect the
monitor to external equipment.
RECORDER OUTPUT - The range of recorder
output can be 0 to -10Vdc, +1 to +5Vdc, or
+4 to +20mA depending on which option is
selected. I n addition, recorder output can be
in either direct or differential mode. I n the
direct mode, the recorder outputs are given for
both channels a n d i s proportional t o the
amount of expansion as measured by each
transducer. I n t h e differential mode, the
recorder output is given on channel A only
and is proportional to the absolute value of the
difference between the expansion as measured
by the two LVDTs.
SELF TEST - T h e monitor h a s three
categories of self test: power-up, cyclic, and
user-invoked.
Power-up s e l f t e s t i s p e r f o r m e d
automatically each time the monitor power
is turned on. A series of basic tests and
transducer OK tests are performed.
Cyclic self test is performed automatically
during m o n i t o r o p e r a t i o n . E r r o r s
encountered during cyclic tests disable the
monitor, and flash an error code on the
LCD bar graph. If the error is intermittent,
the monitor will return to operation, and the
error codes are stored. Error codes can be
read b y performing a user-invoked test.
Stored error codes are indicated by OK
LEDs flashing at 5 Hz provided that the
channel is OK.
The User-Invoked test performs a power-up
self test and allows error messages stored
during cyclic tests to be read and cleared.
Stored errors are annunciated by flashing the
OK LEDs at 5 Hz and displaying the error
codes on the front panel LCD bar graph.
Timed Ok Channel Defeat - The Timed OK
channel defeat function prevents faulty
transducer wiring from causing false alarms.
If a transducer is determined to be Not OK,
the channel OK LED goes off, the Channel
Bypass LED comes on, the channel alarming
is disabled, and the OK relay de-energizes. If
a channel's input signal returns to an OK
condition, the channel's OK LED will start
flashing at a 1 Hz rate to indicate that the OK
state is restored, the Bypass LED will go off,
and after a 10 second delay monitoring is
enabled. The Reset switch on the System
Monitor front panel must be pressed to stop
the OK LED from flashing.
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