IS200VVIBH1A - Vibration Monitor Board

SPECIFICATIONS

Part No.: IS200VVIBH1A
Manufacturer: General Electric
Country of Manufacture: United States of America (USA)
Probe signal sampling: 16-bit A/D converter
Product Type: Vibration Monitor Board
Availability: In Stock
Series: Mark VI

Functional Description

IS200VVIBH1A is an Vibration Monitor Board developed by GE. It is a part of the Mark VI control system. The Mark VI system incorporates Bently Nevada probes for shaft vibration monitoring, with the Vibration Monitor Board playing a central role in processing signals from these probes. This information is obtained from the TVIB terminal board, to which up to 14 probes can connect directly. Two TVIBs can then be cabled to the VVIB processor board. The VVIB digitizes the diverse vibration signals and transmits them over the VME bus to the controller.

Protective Functions in Turbine Applications

Vibration probe inputs are typically utilized for four protective functions in turbine applications:

• Vibration Monitoring: Proximity probes monitor the peak-to-peak radial displacement of the shaft, capturing the shaft's motion within the journal bearing in two radial directions. The system employs non-contacting probes and Proximitors, providing alarm, trip, and fault detection capabilities.
• Rotor Axial Position Monitoring: A probe is strategically mounted in a bracket assembly off the thrust bearing casing to observe the motion of the thrust collar on the turbine rotor. Similar to vibration monitoring, this system utilizes non-contacting probes and Proximitors, resulting in thrust bearing wear alarm, trip, and fault detection.
• Differential Expansion Monitoring: This application employs non-contacting probes and Proximitors to detect excessive expansion differential between the rotor and the turbine casing. It provides alarm, trip, and fault detection for differential expansion issues.
• Rotor Eccentricity Monitoring:A probe, positioned adjacent to the shaft, continuously senses the surface and updates the turbine control. The calculation of eccentricity is made once per revolution during turning gear operation. The system provides alarm and fault indications for rotor eccentricity.

Installation

• Power Down the Processor Rack: Before proceeding with the installation, ensure the processor rack is powered down. This precautionary measure prevents any potential electrical interference or disruptions during the installation process.
• Slide in the Board: Carefully slide VVIB into the designated slot in the rack. Ensure that the board is aligned with the slot and smoothly insert it to establish proper connections.
• Secure the Board with Levers: Once the board is correctly inserted, use your hands to push the top and bottom levers. These levers play a crucial role in securing the board firmly in place, establishing a reliable connection with the edge connectors within the rack.
• Tighten Captive Screws: To further secure the board and prevent any unintended movement, tighten the captive screws located at the top and bottom of the front panel. Use an appropriate tool to ensure a snug fit without over-tightening.

Operation

• Probe Compatibility: TVIB is designed to support a variety of Bently Nevada probes, including Proximitor, Seismic, Accelerometer, and Velomitor probes. These probes are specialized for monitoring different aspects of turbine performance and mechanical conditions.
• Power Supply: Power for the vibration probes is supplied by the Vibration Monitor Board. The VVIB boards, operating in either Simplex or Triple Modular Redundant (TMR) mode, ensure a stable and reliable power supply to the connected probes.
• Probe Signal Processing: The signals from the vibration probes are transmitted, where they undergo processing. TVIB supports Proximitor, Seismic, Accelerometer, and Velomitor probes, and it is capable of handling signals from these sensors with precision.
• A/D Conversion: After receiving the probe signals, TVIB facilitates Analog-to-Digital (A/D) conversion. This process digitizes the analog signals from the probes into digital values, making them suitable for further processing and analysis.
• Communication with Controller: The digitized vibration signals are then sent over the VME bus to the controller. This communication pathway ensures that the processed data is efficiently transmitted to the central control system for real-time monitoring, analysis, and decision-making.

The WOC team is always available to help you with your Mark VI requirements. For more information, please contact WOC.

Frequently Asked Questions

What is IS200VVIBH1A?
It is an Vibration Monitor Board developed by GE under the Mark VI series.

What types of limit checks are performed on the input signal for diagnostics?
Diagnostics include both high/low (hardware) limit checks and high/low system (software) limit checks on the input signal. The software limit check is adjustable in the field to accommodate specific operational requirements.

What conditions trigger a probe fault, alarm, or trip?
A probe fault, alarm, or trip condition is triggered if either of an X or Y probe pair exceeds its predefined limits. Additionally, the application software will inhibit a vibration trip (the AC component) if a probe fault is detected based on the DC component. This multi-layered approach ensures comprehensive monitoring and response to potential issues.

How are position inputs monitored for thrust wear protection, differential expansion, and eccentricity?
Position inputs for thrust wear protection, differential expansion, and eccentricity are monitored similarly to the vibration inputs. However, for position indication, only the DC component is utilized. This enables effective monitoring of shaft position for critical protective functions.

What type of A/D converter is used in the diagnostics system?
The diagnostics system employs a 16-bit sampling type Analog-to-Digital (A/D) converter with 14-bit resolution. The overall circuit accuracy is maintained at 1 percent of full scale, ensuring precise and reliable conversion of analog signals into digital values for further analysis.

How does the software handle vibration trips in the presence of a probe fault?
The software intelligently inhibits a vibration trip (the AC component) if a probe fault is detected based on the DC component. This feature enhances the system's ability to respond to faulty conditions and ensures that vibration trips are appropriately managed in the presence of probe faults.