A Voltage Regulation Complaint Isn't Automatically an EACF Failure

When an EX2100-controlled generator starts drifting on voltage regulation, or the HMI throws a feedback-related alarm, the Exciter AC Feedback board is an easy target — it's the board whose entire job is reporting that voltage and current back to the regulator. Before ordering this IS200EACFG1B as a replacement, work backward through the signal path: check the potential transformer fuses and field wiring feeding the board, check the flux/air-core coil wiring used for current sensing, and check the three DB9 cables running out to the M1, M2, and C controllers. Any one of those can produce symptoms that look exactly like a failed feedback board.

What This Board Measures

IS200EACFG1B is the G1B version of GE's Exciter AC Feedback board for the EX2100 excitation control system, built for the 480 Vrms (+20%) input class. It measures the exciter's three-phase AC supply voltage — stepped down through onboard potential transformers to a nominal 1.6 V rms signal — and current, sensed through flux/air-core coils and filtered against high-frequency noise. The processed measurements fan out to three DB9 connectors feeding the M1, M2, and C controllers, giving the regulator the redundant feedback it needs to hold field excitation steady.

Where It Lives and How Far It Reaches

EACF is mounted in the exciter auxiliary cabinet, separate from the Mark VI turbine control VME rack even though it shares the same IS200 part-numbering convention. Its cable connection back to the EBKP backplane board can run up to 90 meters — long enough that cable and connector condition is worth checking on any installation before you condemn the board itself.

New Surplus, Factory Packaged

This unit is offered new surplus in its original factory packaging. We also stock the G2B variant (1000 Vrms class) separately in used, tested condition — the two are not interchangeable, so confirm your exciter's voltage class before ordering either one.

Checklist Before You Order

• Confirm the fault is isolated to feedback (voltage/current reporting) rather than a downstream regulator or bridge issue.
• Inspect PT fuses and field wiring ahead of the board.
• Check all three DB9 cables to the M1/M2/C controllers individually.
• Confirm you need the G1 (480 Vrms) class specifically — not G2 (1000 Vrms) or G3 (1300 Vrms).

The Part Number

IS200EACFG1B IS200EACFG1BAA: EACF is the functional code, G1 is the 480 Vrms input class, B marks the board-type revision, and AA tracks the specific hardware revision. Our part number decoder covers the full naming structure used across Mark VI and EX2100 boards.

Related Boards

BICL and its matching Bridge Personality Interface board (BPIA/BPIB/SCNV) are common companions in the same EX2100 cabinet. See our Mark VI IS200 boards collection for the rest of the catalog.

What to Send With Your RFQ

• Full part number and suffix (IS200EACFG1BAA)
• Exciter voltage class, if known
• Generator/turbine model and site
• Quantity and urgency

Request a Quote

This board is quoted, not sold at checkout. Send us your part number and timeline through Request a Quote and expect DDP pricing within 24 hours. We ship worldwide and accept purchase orders.