Mark VI is the VME-based generation of GE's Speedtronic turbine control line. Its boards carry the IS200 prefix, and you will also see IS210, IS215 and IS220 numbers — all Mark VI-era, and heavily cross-referenced against each other by suppliers.
The one question to answer before you order: TMR or simplex?
This is the difference that catches people out, and it is worth understanding before you buy anything.
The Mark V that preceded it was designed as a triple modular redundant system — full stop. Mark VI was designed to offer both TMR and simplex control. That means two Mark VI panels can be architecturally different from one another, and the correct board depends on which one you have in front of you.
The fastest way to tell, without pulling a single document: look at the VCMI communications board and count its IONet ports. The simplex version has one. The TMR version has three. That single observation tells you which architecture your rack is running, and it is the first thing we will ask you.
The board families
- UCVx — the controller. Single-slot VME boards (for example the IS215UCVEH2AAE). External data reaches the controller through the VCMI; depending on the system it arrives as process I/O (simplex) or voted I/O (TMR).
- VCMI — the VME communications interface and bus master. Comes in Simplex and TMR versions, which are not the same part. One IONet port versus three.
- VTUR — turbine protection. Measures turbine speed to generate the primary overspeed trip, controls the three primary overspeed trip relays on the TRPx terminal board, and monitors eight flame detectors.
- VPRO — the companion protection module.
- VAIC / VAOC — VME analog input and analog output cards. These replace the Mark V TCQA / TCQC family; they are not related parts.
- STCI and the terminal boards — the field-wiring landing points, such as the DIN-rail contact terminal boards. They fail rarely, but from the HMI a failed terminal board is indistinguishable from a failed VME card. Ring them out first.
The prefix trap
IS200, IS210, IS215 and IS220 are all Mark VI numbers. Some boards genuinely appear under more than one prefix; others do not. Do not assume a prefix difference means a different board, and do not assume it means the same board. Quote the full number and let us confirm against what is physically on the shelf.
The same applies to the revision tail. IS200PSCDG1A and IS200PSCDG1ABB describe the same board — the second carries its revision letters. Buyers regularly search one form, find nothing, and conclude the part is unavailable. Search both.
Protection-path parts are different
If the board you need is anywhere in the protection path — VTUR, VPRO, or the trip relays they drive — revision and architecture matching are not optional. A protection card that is subtly wrong may work perfectly until the day it was supposed to act.
Availability
Mark VI is still widely supported and is where most GE fleets currently sit. That makes it the easiest Speedtronic generation to source — but "easiest" is relative, and specific revisions still go scarce without warning.
Requesting a quote
Send us the full part number with the revision tail, whether the panel is TMR or simplex, the rack and slot, whether you can accept an alternate prefix or a superseding revision, and whether this is a breakdown or a shelf spare. We reply within 24 hours, ship worldwide DDP, and accept purchase orders.
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