80176-01
Dual Vibration Monitor Operation
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MONITOR FUNCTIONS
RADIAL VIBRATION - Radial vibration is defined as shaft dynamic motion in a direction perpendicular to the shaft
centerline. The Dual Vibration Monitor displays vibration values for two channels (Channels A. and B).
PROBE GAP VOLTAGE - Probe gap is measured as a negative dc voltage that is directly proportional to the gap
distance between the face of a proximity probe and the surface being monitored. Probe gap voltage for each chan-
nel is displayed on the front panel meter by pressing the GAP switch.
OK - When the Proximitor output voltage is within its upper/lower OK voltage limits, the transducer is defined as
()K. The OK detection circuit controls the channel OK LED and the monitor relay drive to the OK relay.
OK RELAY - The OK Relay is located on the Power Input Module. Every channel in the rack must be OK or
bypassed to energize the OK Relay.
TIMED OK/CHANNEL DEFEAT - Timed OK/Channel Defeat minimizes faulty transducer wiring from causing
false alarms. I f the r o b e input signal level on a given channel is not within upper/lower limits, that channel OK.
LED goes off, the BYPASS LED goes on, the channel is disabled, and the OK Relay dcenergizes. I f the channel
input signal level is restored within the upper/lower OK limits for 30 seconds, the channel- OK LED will start
flashing at 1 Hz to indicate the OK state is restored, the BYPASS LED goes off, and monitoring is enabled. The
RESET switch on the front panel of the System Monitor must be pressed to stop the OK LED from flashing (it
remains on). If the channel remains in the NOT OK state, a Channel Bypass switch on the monitor circuit board can
be set to put the channel "out of service". The monitor can then be operated as a single-channel monitor. Without
this feature, the OK Relay could not be reactivated. In the Timed OK/Defeat and Channel Bypass modes, there is
no recorder output and the meter registers zero.
ALARM - Pressing the ALERT or DANGER switch on the front panel of the monitor causes the corresponding
Alert (first-level alarm) or Danger (second-level alarm) alarm setpoints on each channel to be displayed on the front
panel meter. A L E R T and DANGER LEDs light when the vibration signal level exceeds preset levels for the
selected time delay, and appropriate Alert and Danger alarm relay contacts are activated. Voting logic options
determine when the Danger alarm relay contacts are activated.
FIRST OUT - Separate First Out circuits exist for Alert and Danger alarms. A monitor with First Out Option
selected flashes a channel alarm LED if that channel was the first channel in the rack to go into alarm. Pressing the
RESET switch acknowledges the First Out condition. This allows the next channel in the rack that goes from non-
alarm-to-alarm condition to indicate First Out by flashing its alarm LED.
ALARM RELAYS - Monitor alarms can be programmed for either latching or nonlatching mode. I n the nonlatching
mode, the alarm resets automatically when the alarm no longer exists. I n the latching mode, the alarm condition
must be reset manually by pressing the RESET switch on the front panel of the System Monitor (or by closing
external Reset contacts). The alarm will not reset if the alarm condition still exists.
DANGER BYPASS - For maintenance functions, a DANGER BYPASS switch on the monitor circuit board is set to
inhibit the Danger relay drive. This function turns on the BYPASS LEDs. Other front panel functions are not
effected. This function can be disabled using a jumper within the monitor.
BUFFERED OUTPUT - The Channels A and B coaxial cable connectors on the front panel of the monitor and
terminals on the Signal Input Relay Module provide buffered signals from the respective channel transducers.
These connectors can be used for connection of external equipment.
TRIP MULTIPLY - The Trip Multiply function multiplies set points by 2X or 3X in response to an external contact
closure through terminals on the Power Input Module. The front panel meter and recorder outputs could saturate
in this mode.
RECORDER OUTPUTS - Depending on the option selected, the recorder output levels proportional to measured
vibration are either 0 to -10 Vdc, +1 to +5 Vdc, or +4 to +20 mA.
SELF TEST - The monitor has three categories of self test: cyclic, power up, and user invoked.
• Power up self test is performed automatically each time the monitor power is turmed on. A series of basic
tests and transducer OK tests are performed. upon completion of the tests, if no errors, the monitor will
performtimcd OK channel defeat and monitoring will resume in 30 seconds.
• Cyclic self tests is performed automatically during monitor operation. Errors encountered during cyclic tests
disable the monitor, and flash a led bargraph error code. Should the error be intermittent the
monitor
will
return to operation, but the error codes are stored for retrieval during user-invoked self tests. ;:j)red error
codes are indicated by OK LED's flashing at 5 HZ provided that the channel is OK
• User invoked test performs power up self test and allows error messages stored during cyclic tests to be read
and cleared. stored errors arc annunciated by flashing the OK LEDs at 5 HZ and displaying the error codes
on the front panel LCD bargraph.
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