To Configure Gap4_Vib4; Velocity; Velocity Input Processing - GE Mark VIeS System Manual

➢ ➢ To configure GAP4_VIB4
From the ToolboxST Component Editor, navigate to the Gap 4-8 tab.
1.
2. Select GAP4_VIB4, and click the Show Advanced Parameters icon.
3. Configure it to match the following example.
Click the Vib 1-8 tab.
4.
5. Select VIB4 and click the Show Advanced Parameters icon.
6. Configure it to match the following example.
If the YVIB firmware is receiving the data successfully after competing this configuration, then the following occurs:
• Gap values are passed through a 2-pole, low-pass filter with a cutoff frequency of 8 Hz. This will attenuate the 50Hz, 2Vpp
vibration by nearly 40:1, and the DC component of 10 V dc will be unaffected. The DC wave will be converted to 50mils, and
the 40:1 reduced AC wave will be converted to ±0.125 mils, so the GAP4_VIB4 value will be 50 ± 0.125 mils.
• SysLim1GAP4 and SysLim2GAP4 are false, since (45.0 ≤ 49.875) and (50.125 ≤ 55.0).
• Vibration Displacement is unaffected by the DC component of the signal. The 50Hz, 2Vpp AC portion will be passed
through a peak detection with 160 ms scan period, which will capture 8 cycles. The Peak-to-Peak value will return 2Vpp,
which will be converted to 10mils, so VIB4 value will be 10mils.
• SysLim1VIB4 will be true, since VIB1 ≥ 8.0 mils. SysLim2VIB4 is false.

8.3.3.4 Velocity

Inputs 1-8 support Velomitors, Seismeic velocity, and Accelerometers with integrated outputs to collect wideband velocity.
Inputs 1-3 also collect velocity magnitude relative to a specified rotor speed. In LM turbine applications, Velocity sensors are
mounted on bearing housings or machine casing to provide measurements of vibration. Tracking filters for Inputs 1-3 can
provide the magnitude of vibration at a specified frequency.

Velocity Input Processing

GAPn_VIBn – Sensor biasing voltage in Volts.
Gap values are filtered through a 2-pole, low-pass filter with a fixed cutoff frequency of 8 Hz. The output of the gap filter is
passed through a rolling average filter prior to scaling. For Velocity sensors, the gap value is not scaled, and it will remain in
Volts. This value can be used to monitor sensor health.
VIBn – Wideband Velocity (½*pk-pk or RMS) in engineering units (EU).
Wideband velocity information is passed through 1-pole, high-pass filter with a fixed cutoff frequency of .1Hz. This removes
static information prior to wideband filtering. This data is passed through the wideband filter, which can be configured as a
low-pass, high-pass, or band-pass filter. The high-pass and low-pass filters can be configured for 2, 4, 6, 8, or 10 pole
Butterworth filters with a user-defined cutoff (-3dB) point.
252 GEH-6855_Vol_II
V
FILT
Gap
V
PROX
Filter
GEH-6855_Vol_II Mark VIeS Functional Safety Systems Volume II
V
GAP
Mvg
Avg
GAPn_VIBn
Filter
Public Information