What DS200DCFBG1AAA Does

DS200DCFBG1AAA is a DCFB – a Power Supply Board GE built for its EX2000 excitation control system, with the same board design also used across the DC2000, CB2000, FC2000, GF2000, ME2000, and AC2000 IGBT drive families (the board is used somewhat differently in EX2000 excitation service than in a straight drive application). Its core job is to deliver control-level power to the drive or exciter and 115 VAC power to the enclosure cooling fans, using 38 VAC and 115 VAC input from the control power transformer (CPT). Onboard circuits include control-level power supplies (+5 V, ±15 V, ±24 V), motor/generator field power circuits, driver circuits for the armature SCR gate pulse generators, and instrumentation circuits monitoring AC line and DC motor signals.

The DCFB works hand-in-hand with the SDCC drive control card (or the LDCC card on EX2000 systems), exchanging power-good and feedback signals over the 1PL and 2PL connectors. The CPT's 38 VAC feed is rectified and filtered to ±24 VDC (+24 V at 3 A, -24 V at 1 A); onboard regulators derive ±15 VDC from those rails, and the +24 VDC supply also produces a +5 VDC, 4 A output. That +5 V rail matters more than it might seem – more on that below.

How to Diagnose a DCFB Fault Before You Buy

This is the section that actually saves you money, because a "bad DCFB" and a "bad SDCC/LDCC" can look identical from the fault code alone. The DCFB generates a /PSEN (power sense) signal on connector 2PL: when the +5 VDC supply is properly regulated, /PSEN sits TTL-low; if that supply sags out of regulation, /PSEN goes high – and that forces the SDCC or LDCC drive control card's microprocessor to reset. In practice, that means a drive or exciter that keeps rebooting or resetting can be a DCFB power supply problem wearing an SDCC/LDCC costume. Before replacing either card:

• Check the DCFB's fuse-status indicators first. LEDs CR51 and CR55 flag a blown FU2 or FU3 (7 A power-output fuses); a neon lamp LT1 flags a blown FU1 (the 1/2 A fuse protecting the 115 VAC fan output).
• Verify the +5 V and ±24 V rails feeding the SDCC/LDCC before assuming the drive control card's logic itself has failed.
• Don't assume a repeat failure means a bad batch of boards. Field experience from long-time Mark V/EX2000 technicians is consistent on this point: if the same card position keeps failing in a short period, the more likely explanation is a field device, wiring, voltage, or current problem downstream of the card – not a defective replacement. Chasing the symptom with card after card without checking the external circuit tends to just burn through spares.
• Component-level failures (like an aging capacitor) can mimic a DCFB fault even when the DCFB itself is fine – there are documented cases of repeated "DCFB failures" on an EX2000 panel that actually traced back to a failing capacitor on the companion LDCC card. GE never released full schematics for this card generation, which is part of why isolating a single bad component without specialized test equipment can be difficult – a repair shop with card-level test fixtures is often the fastest path to a confirmed root cause.

Reading DS200DCFBG1AAA

DS200 is the board series prefix, DCFB is the Power Supply Board functional acronym, G1 is this board's product grouping, and AAA is the specific functional and artwork revision combination of this unit – in fact, the absence of trailing revision digits beyond a base A-rating marks this as very close to the original version of the DCFB design. GE's instruction manual for this board is referenced as GEI-100028. We have not found a documented functional split between the G1 and G2 DCFB groups the way there is for some other DS200 boards, so treat G1 vs. G2 as a hardware/manufacturing revision rather than a feature difference, and match the exact suffix on your existing card rather than assuming either group is interchangeable.

Related Boards and Newer Platforms

The DCFB is almost always discussed together with the SDCC (Mark V/DC2000-side) or LDCC (EX2000-side) drive control card it powers and interacts with, and the TCPS power supply elsewhere in the panel. If your site is evaluating a longer-term move away from Mark V/EX2000-era hardware, see our Mark V vs Mark VI: DS200 to IS200 guide for the general picture. For how GE's Speedtronic part numbers are constructed, see the GE Speedtronic Part Number Decoder, and for context on the DS200 board family as a whole, see GE Mark V DS200 Boards Explained.

What to Send With Your Quote Request

• The complete part number and suffix, e.g., DS200DCFBG1AAA
• A photo of the label, if possible
• Turbine/generator model and whether this feeds an EX2000 exciter or a DC2000-family drive
• Quantity needed
• Urgency – planned outage or active fault

Request a Quote

This DS200DCFBG1AAA is offered used, cleaned and tested, with a 1-year warranty (see below). Pricing isn't published online since these quotes depend on exact revision match and current stock – submit a Request a Quote and our team will respond within 24 hours. We ship worldwide DDP, accept purchase orders, and support both planned outages and urgent turbine-down orders.

General Information about the Product
Part Number	DS200DCFBG1A Mark V DS200
Description	DS200DCFBG1A By General Electric DS200DCFBG1AAA EX2000 Power Supply Board
Condition	used Cleaned and Tested. With 1 Year Warranty.