Seismic Sensors; I/O Variable Name, Vibx - GE Mark VIeS System Manual

JPxA jumper is in the "P,A" position providing a +28 V weak pull-up for sensor failure detection and the JPxC jumper is in
the "PCOM" position to provide a closed circuit for the -28 V power applied to the sensor through the WNPS -28 V
daughterboard for TVBAH#A or TVBAS#A terminal boards only. JPxB is set in the 'PVA' position.

8.5.2.2 Seismic Sensors

The TVBA can input a maximum of eight seismic sensor inputs on channels 1 through 8. Seismic sensors are usually
moving-coil type probes that require no power. The heavy-duty gas turbines (HDGTs) use the Metrix 5235B, 5475C or 5485C
sensors on the bearing housings to measure the non-rotating vibration. The Metrix 5485C or similar sensor's output is
connected directly to the PRxxH and PRxxL inputs. The seismic output is centered at 0 V dc. With a sensitivity range of 100
to 200 mV/in/sec. Tie the shield on the Mark VIeS end and leave the shield open on the sensor side.
Not Used
Seismic
5485C
JPxA jumper is in the 'S' position providing a -28 V weak pull-down for sensor failure detection and the JPxC jumper is in
the 'PCOM' position to allow the corresponding buffered output to be scaled the same as the signal input.
JPxB is set in the 'S' position.
YVIB Vibration Monitor Modules

I/O Variable Name, VIBx

Transient
Suppression
Transient
PRxxH
Suppression
PCOM
3.6mA
Transient
PRxxL
Suppression
PCOM
Shield
Public Information
-28V to -24V Regulator
with current limit
V P,A
JPxA
S
OPEN
JPxC
GEH-6855_Vol_II System Guide 277
-28V
YVIB /
PVIB
+28V
Vibration
-28V
Inputs
Vib: 1 – 8
Tracking
Filter: 1 - 3