What the IS200VTURH1BAB Does in a Mark VI Rack

Supplied as new-surplus factory-packaged stock, the IS200VTURH1BAB is the VME turbine (VTUR) card that carries primary turbine protection in the GE Speedtronic Mark VI. It is the board that converts raw magnetic speed-pickup signals into the turbine's speed feedback and its primary overspeed trip, while also monitoring induced shaft current and voltage and, on gas machines, the flame detectors. It occupies a slot on the VME control bus and depends on the TTUR terminal board for its field connections.

Primary protection in the control cores

In a Mark VI, VTUR provides the primary layer of turbine protection. It accepts up to four passive magnetic pickups over roughly 2 Hz to 20,000 Hz, takes the median speed for control and for the primary overspeed trip, and can resolve very low shaft rotation to support zero-speed and turning-gear logic. On an overspeed event it energizes three primary trip relays on the applicable TRPx terminal board (TRPG on gas turbines, TRPS or TRPL on steam), which drive the emergency trip devices. In a TMR architecture one VTUR resides in each control core, <R>, <S>, and <T>, and their outputs are voted for security against a single-card fault; simplex systems run a single VTUR. Independent emergency overspeed is provided separately by VPRO in the <P> protection core.

Is it the VTUR, the TTUR, or the field wiring? Diagnose first

A brand-new protection card is worth fitting only once you know the card is the problem. The following faults frequently point somewhere other than VTUR:

• Missing or jumpy speed reading. Check the magnetic pickup, its air gap, the field wiring to TTUR, and the JR5 speed cable first. A single bad channel in a TMR set is voted out and rarely means the card has failed.
• Overspeed trip that should not have happened, or a trip test that will not complete. Look at the TRPx and TREx trip boards, the ETD (trip solenoid) wiring, and the trip power supply before the VTUR itself.
• Flame-detector alarms on a gas turbine. The Geiger-Mueller detectors run through TRPG on an external supply; soot on the detector or a supply fault mimics a card problem.
• Automatic synchronizing or 52G breaker trouble. The generator and bus PT inputs and the breaker relays sit on TTUR, so this class of fault usually is not the VTUR.
• The controller does not recognize the card. Reseat it, verify backplane and rack power, and check that the firmware revision matches the system.

Using the HMI fault log to see which element actually latched will save you from swapping a healthy board.

Reading the VTUR H1B revision and suffix

The identifier is layered: IS200 for the Mark VI IS200 series, VTUR for the VME turbine primary-protection function, H1 for the hardware group, B for the functional revision, and AB for the artwork and coating revision. H1A, H1B, and H2B are revisions of the same board function, and some installations expect a specific revision, so confirm the complete string on your existing card. The GE Speedtronic Part Number Decoder details how the code is constructed.

Related turbine-protection hardware

Plan the VTUR alongside its partners: the TTUR input terminal board (speed, shaft, PT and breaker wiring, linked via JR5 and JR1), the TRPx/TREx trip boards, and the independent VPRO emergency protection card. Explore these in the GE Mark VI IS200 Boards collection and the broader GE Speedtronic Turbine Control Boards range. GE documents the VTUR in the Mark VI System Guide, GEH-6421, and our Mark V vs Mark VI: DS200 to IS200 guide explains how protection migrated from the earlier platform.

Quote request checklist

• Full part number with suffix (IS200VTURH1BAB) and any revision codes on the label
• A photo of the board label
• Turbine model and Mark VI generation
• Simplex or TMR, and the affected core if known
• Quantity and how urgent the need is

Request a quote on this new-surplus card

This IS200VTURH1BAB is new-surplus, in original factory packaging, backed by the warranty listed below. Click Request a Quote for a reply within 24 hours. We ship worldwide DDP and accept purchase orders from qualified organizations. Given the card's protective role, share your turbine details and timeline so we can confirm the correct revision and lead time.