IS215VPROH1B: Role in Emergency Overspeed Protection

On a GE Speedtronic Mark VI, the IS215VPROH1B is one of three VPRO boards that make up the turbine's emergency overspeed protection system. It is deliberately kept independent of the turbine control processors: the Mark VI's normal speed control can misbehave without the VPRO cores being affected, which is the point of separating protection from control.

Working with the TPRO and TREG terminal boards, the three VPRO channels drive the trip solenoids that shut the turbine down in an emergency. The board does not make decisions about day-to-day turbine operation; it watches, and if needed, acts.

H1 vs H2: Why This Board Supports a Second TREG

The H1 (this board) and H2 versions of VPRO differ mainly in power and TREG support. H1A and H1B support a second TREG terminal board, wired from VPRO connector J4, useful on configurations that need the extra trip channel. H2 is a lower-power design that supports only one TREG. If your installation currently uses two TREG boards per channel, an H2 board is not a like-for-like substitute — you need an H1. H1A has been superseded by the functionally equivalent H1B, so if your existing board is stamped H1A, an H1B is the correct replacement.

Troubleshooting Tips Before You Order a Replacement

Before ordering a VPRO, it's worth spending a few minutes ruling out the things that look like a VPRO failure but are not:

• Each VPRO channel has its own dedicated switch and fuse in the PD (power distribution) core. A board with no LED activity at all is sometimes a blown fuse or open supply switch at the PD, not a dead card.
• VPRO and VCMI communicate over the same IONet loop. A failing VPRO channel can produce VCMI diagnostic alarms on all three control cores at once — don't assume every alarm you see points to a separate bad board.
• GE TIL-1905 covers a known intermittent-communication issue tied to a socketed IONet transceiver chip on boards built between May 2006 and February 2009 (VPRO and VCMI alike). Oxidation at the socket, not board failure, is the root cause in those documented cases.
• Field reports describe VPRO boards being swapped without shutting the turbine down, since each channel is powered and wired independently — but only after confirming the other two channels are alarm-free, since diagnostic alarms on the remaining channels can combine with a powered-down channel to cause an unwanted trip.

We keep this section diagnostic only. Anything involving an actual overspeed trip test belongs in GEH-6421 and your plant's approved procedure, not in a parts listing.

Decoding the IS215VPROH1BH Suffix

IS215 marks the Mark VI-generation assembly; VPRO is the function; H1 is the design group covered above (dual-TREG capable); H is the specific revision letter on this unit. Match revisions to what your Toolbox configuration expects — send us a photo of your existing board's label if you're unsure, and we'll confirm fit before you commit to an order.

Companion Boards and Cross-Generation Notes

Most VPRO replacements happen alongside work on VCMI, terminal boards, or a broader Mark VI spares plan. Use our GE Speedtronic Part Number Decoder to check any other IS200 or IS215 board pulled during the same outage, and see Mark V vs Mark VI: DS200 to IS200 if you're supporting older Mark V equipment in parallel. The full board lineup is in our GE Mark VI IS200 Boards collection.

Information We Need for Your Quote

• Complete part number and suffix (IS215VPROH1BH), including revision letter
• A photo of the label on the board you're replacing
• Turbine model and control configuration (simplex or TMR)
• Quantity and how soon you need it on site

Get a Quote Within 24 Hours

This IS215VPROH1BH ships as new surplus, factory packaged, backed by a 1-year warranty. We quote worldwide with DDP shipping and accept purchase orders, with quotes returned within 24 hours. Click Request a Quote and tell us about your outage — we don't list prices here because every quote reflects your specific board, condition, and timeline.

General Information about the Product
Part Number	IS215VPROH1B Mark VI IS215
Description	GE IS215VPROH1B IS215VPROH1BH Emergency Turbine Protection Board Mark VI NEW
Condition	newSurplusFactoryPackage With 1 Year Warranty.