IS200ECTBG2A: The Simplex Exciter Contact Terminal Board

Where redundant EX2100 exciters use the ECTBG1, simplex systems use this board — the IS200ECTBG2A. It performs the same fundamental job in GE's EX2100 Excitation Control: terminating the exciter's hardwired contact inputs and relay contact outputs so the control electronics can read plant status and drive trip and annunciation circuits. The difference is architectural. In the G2A simplex arrangement there is a single control channel, so only the M1 controller connects to the board; per the EX2100 documentation, the trip relays on a simplex board are designated K1M1 and K2M1 and their drivers receive 24 V dc from M1, with no cross-channel voting involved.

One point worth stating plainly, because the IS200 prefix causes confusion: this is excitation hardware from the EX2100 platform, a sibling of — not a member of — the Speedtronic Mark VI turbine control system. Catalogs, including the summary table on this page, commonly file IS200-prefix boards under Mark VI; the physical board belongs in the exciter cabinet.

Contact I/O Capacity as Documented

• Two trip contact outputs, each using two parallel normally closed contacts, typically wired to drive a customer lockout device.
• Four Form-C general-purpose relay outputs (K1GP–K4GP) offering common, normally open, and normally closed terminals for externally powered circuits, commonly at 125 V dc.
• Six customer auxiliary contact inputs, wetted at 70 V dc sourced through the board's power plugs, plus powered monitoring of the 52G and 86G contact inputs.
• Three 25-pin D-sub connectors — J405, J408, and J415 — cabling the board to the EBKP backplane, where the EMIO (Exciter Main I/O) board reads inputs and commands the relay drivers. Terminal blocks TB1 and TB2 are removable for wiring work.

Symptoms That Point Away From the ECTB

Because this board is mostly relays, terminals, and wetting distribution, several classic "ECTB failures" are really something else. Check these before ordering:

• Every contact input dead at once. A board full of healthy inputs does not fail simultaneously. Verify the 70 V dc wetting supply reaching the board — in simplex systems there is no second supply to fall back on, so a lost feed takes down all six inputs together.
• Output relay never operates. In simplex control the command originates at the EMIO in the M1 channel. If the driver command never arrives — EMIO fault, backplane cable, unseated D-sub — a perfectly good ECTB looks dead.
• Contacts operate but the load does not. The Form-C outputs switch customer-supplied power. Confirm the external supply and load wiring before touching the exciter.
• Erratic input indications. Corroded field contacts and marginal wiring produce flickering indications that look like board-level sensing faults. The per-input LED is your friend: if it tracks the field contact cleanly, the input circuit is doing its job.

G2A vs G1A: Why the Group Code Is Not Interchangeable

The part number decodes as IS200 + ECTB + G2A + DE. The group, G2A, is the simplex build; the G1A group is reserved for redundant systems where drivers from M1, M2, and C are voted 2-out-of-3. GE documented the two groups as exclusive to their respective architectures, so match the group on your existing board — do not substitute across it. The trailing DE is the revision level of this particular unit; supply the full string from your label and we will confirm the match. For a plain-English tour of GE's numbering, see the GE Speedtronic Part Number Decoder.

How to Get an Accurate Quote Fast

Send us: the complete part number with revision (IS200ECTBG2ADE), a photo of the board label if possible, confirmation that your EX2100 is a simplex system, the machine it serves, quantity, required delivery timeframe, and destination country. That is everything needed to quote in a single exchange — and if you are also evaluating the EMIO or other exciter boards, list them in the same request. Related inventory is in our GE Mark VI IS200 Boards collection and across the GE Speedtronic Turbine Control Boards catalog.

Factory-Packaged Surplus — Request Your Quote

This IS200ECTBG2ADE is new surplus in its original factory package, tested and covered by the warranty listed below. Hit Request a Quote and our team will reply within 24 hours with availability and lead time. Shipping is DDP worldwide — we handle export, customs, and duties through to your receiving dock — and purchase orders are welcome.

General Information about the Product
Part Number	IS200ECTBG2A Mark VI IS200
Description	IS200ECTBG2A By GE IS200ECTBG2ADE Exciter Contact Terminal Board NSFP
Condition	newSurplusFactoryPackage Clean and Tested. With 1 Year Warranty.