IS200TVBAH2A is a Vibration Input Terminal Board and is part of the GE Speedtronic Mark VIe gas turbine control system. The PVIB / YVIB I/O pack uses the Vibration Input (TVBA) terminal board as a signal interface board. Seismic (velocity), Proximitors, Velomitors, and accelerometer-type probes can all directly connect with the TVBA. For each input signal, the terminal board offers electromagnetic interface (EMI) protection and signal suppression. To enable open circuit identification, signals are additionally coupled to a pull-up bias. Through a 37-pin connector, the signals are sent to the I/O packs.
IS200TVBAH2A Functional Description
- You can utilize the component for simplex or TMR applications. Three I/O packs are fanning the signal using TMR applications. The TVBA contains buffered outputs to additional connectors beyond the conventional 37-pin connection. This feature enables the Bently Nevada 3500 monitoring system to be powered via specific 9 and 25 pin connectors. This feature also includes a bayonet nut connection (BNC) connection for each channel to feed other third-party monitoring apparatus. Mark RKPS power supply are not used by VIe/VIeS control systems.
- There is no external source of -28 V electricity; power is acquired from sourced +28 V power supplies.
- The module features three detachable daughterboards to convert +28 to -28 as a result. All negative power used by the TVBA comes from these WNPS (negative power supply) boards.
IS200TVBAH2A Installation
Installation 14 sensor inputs that are wired directly to two I/O terminal blocks are accepted by the TVBA. Each block has 24 terminals that may accommodate wires up to #12 AWG and are secured with two screws. Each terminal block is close to a shield termination attachment point.
Input Channels 1 through 8:
- Support for Proximitors, Seismics, Accelerometers (only channel 1, 2, and 3), and Velomitors.
- Current-limited -24 V power supply per channel. JPxA jumper for configuring the open circuit check support and 3 mA constant current feed for Velomitors.
- JPxB jumper for configuring the JA1 and JB1 outputs for the Bently Nevada 3500 rack.
JPxC jumper for configuring PR0xL as Open for true
Input Channels 9 through 12:
- Only Proximitors sensors are supported.
- Each channel has a current-limited -24 V power supply.
- Jumper setup is not allowed.
Input Channel 13:
- Proximitors or Keyphasor proximity sensors are supported on Input Channel 13.
- Each channel has a current-limited -24 V power supply, and jumper configurations are not allowed.
-28 V power supply board, WNPS:
- Changes +28 V from PVIB/YVIB to -28 V for the outputs' current limits of -24 V.
- Independent +28 V inputs and a shared -28 V bus for all three WNPSs
- One WNPS per PVIB/YVIB
Operation
14 sensor connections are supported by the TVBA:
- Eight Positions or vibrations (ckts 1 through 8)
- Only four positions (ckts 9 through 12)
- One Keyphasor (reference probe) or location (ckts 13)
- A single Reference probe (Keyphasor)
Probe Power Supplies
A -24 V power supply is offered by each channel. The supply may generate up to 12 mA at a time. Currently, there is only enough supply to satisfy Class 1, Div. 2 requirements.
- -24.5 V (-23 to -26) as the output
- Iout: maximum 12 mA
Buffered Outputs
Every channel has additional outputs in addition to the conventional 37-pin connection. The signal output is a buffered copy of the signal under observation. A BNC connector is used to output each channel. The buffers must meet the following requirements:
- 0.1 percent precision in amplitude
- Add a bias of 5%, -11 V dc, to seismic signals.
- When interacting with Velomitors, sink 3 mA.
- For DB9 and DB25 connections, unity-gain buffered output drives an impedance of 1500 and capacitive up to 1000 pF with less than 10% overshoot.
- The buffered outputs operate in parallel to drive DB25, DB9, and BNC coaxial connectors. The DB connectors are resistively isolated from the central pin and shell of the BNC connector. Even if the BNC connector is shorted, there is enough isolation to keep the voltage at the DB connector within specifications.
- A BNC output drives an impedance of at least 2E+06 ohm.
IS200TVBAH2A Diagnostics
The terminal board is subjected to the following diagnostic examinations:
For each vibration input, the board provides open circuit detection. A diagnostic warning (fault) is generated by the I/O processor if any of the inputs have an out-of-range voltage.
The I/O board interrogates each cable connector's unique ID device on the terminal board. The terminal board serial number, board type, revision number, and the placement of the JR, JS, and JT connectors are all encoded on a read-only chip known as the ID device. A hardware incompatibility fault is produced when the I/O processor reads this chip and runs across a mismatch.
