IS200VTURH1BAC: VME Turbine Card for Speedtronic Mark VI

The IS200VTURH1BAC is a factory-packaged VME turbine protection card for GE's Mark VI, one of the most safety-critical boards in the Speedtronic control rack. In everyday shorthand it is the VTUR, the card that turns shaft speed-pickup pulses into turbine speed and the primary overspeed trip, monitors induced shaft voltage and current, and, on gas turbines, oversees the flame detectors. It seats on the VME control bus and relies on the TTUR terminal board to bring in the field signals.

Overspeed, shaft, and flame monitoring

Three protective duties define this board. First, speed and overspeed: VTUR takes up to four passive magnetic pickups across roughly 2 Hz to 20,000 Hz, uses the median value for speed control and the primary overspeed trip, and drives three primary trip relays on a TRPx board (TRPG, TRPS, or TRPL depending on the turbine) that command the emergency trip devices. Second, shaft monitoring: it measures induced shaft voltage and current and alarms on excessive levels. Third, flame supervision on gas units: it monitors up to eight Geiger-Mueller detectors that interface through the TRPG board on an external high-voltage supply. In a TMR system a VTUR runs in each of the <R>, <S>, and <T> control cores with voting; a simplex system uses one, and VPRO in the <P> core provides independent emergency overspeed protection.

Before you replace the VTUR: check the trip chain and pickups

Because the card is costly and central to protection, it is a frequent casualty of misdiagnosis. In most cases the fault sits in the sensors or the terminal boards:

• Speed problems usually originate at the magnetic pickup, its gap, the wiring to TTUR, or the JR5 speed cable. Verify these before suspecting the card, and remember that a lone bad channel in TMR gets voted out.
• Trip anomalies, whether a spurious trip or a failed trip test, commonly involve the TRPx and TREx boards, the trip-solenoid wiring, or the trip power feed rather than the VTUR.
• Flame faults on gas turbines are often a fouled Geiger-Mueller detector or a fault in its external supply through TRPG.
• Synchronizing or 52G breaker faults point to TTUR, where the PT inputs and breaker relays live, more than to the VTUR.
• Communication faults call for reseating the card and checking backplane power and firmware revision before condemning it.

Reading the HMI diagnostics to see which element actually tripped is the fastest way to avoid replacing a good board.

The IS200VTURH1BAC naming, explained

The string decodes as IS200 for the Mark VI IS200 board series, VTUR for the VME turbine primary-protection function, H1 for the hardware group, B for the functional revision, and AC for the artwork and coating revision. Because H1A, H1B, and H2B are revisions of the same function and some systems expect a particular one, match the entire code to the board you are replacing. Our GE Speedtronic Part Number Decoder lays out each field of the number.

Where the VTUR sits among Mark VI boards

The VTUR is one element of the Mark VI protection set. Its field wiring lands on the TTUR terminal board (connected via JR5 and JR1), its trip commands pass through the TRPx/TREx boards, and independent emergency protection comes from VPRO. Browse related items in the GE Mark VI IS200 Boards collection and the wider GE Speedtronic Turbine Control Boards catalog. GE's Mark VI System Guide, GEH-6421, documents the card in detail, and our Mark V vs Mark VI: DS200 to IS200 guide traces how protection hardware evolved.

Speeding up your quote

• Full part number and suffix from the label (IS200VTURH1BAC), plus any revision codes
• A clear photo of the board label
• Turbine model and Mark VI generation
• Simplex or TMR configuration, and the affected core if known
• Quantity and urgency

Ask for a quote

This IS200VTURH1BAC is new-surplus, factory-packaged, and backed by the warranty shown below. Select Request a Quote and we respond within 24 hours. We ship worldwide DDP and accept purchase orders from qualified organizations. Tell us your turbine model and timeline so we can confirm the right revision and lead time.