The DS200DCFBG1B is a multi-function power supply board designed by General Electric (GE) Industrial Control Systems for its DC2000, CB2000, EX2000, FC2000, GF2000, ME2000, and AC2000 IGBT drive systems. This board belongs to the DCFB (DC2000 Power Supply Board) series, is part of the G1 group, and represents revision level B, which incorporates functional optimizations and reliability improvements over the G1A revision.
The DS200DCFBG1B power supply board is a core component of the drive control system. It receives 38 V and 115 V ac input (or 24 V dc input) from the control power transformer (CPT) and provides stable, reliable control-level power to the drive system, as well as 115 V ac power (not applicable for some models) to the enclosure fans. This board integrates multiple functions, including power conversion, signal conditioning, voltage/current feedback processing, SCR firing control, and AC line monitoring, making it a critical component for achieving precise control and reliable protection in drive systems.
This product is widely used in DC drive systems, excitation systems, variable frequency drive systems, and various industrial process control applications, particularly in environments requiring high-precision current/voltage feedback and highly reliable power management.
II. Key Functions
1. Multiple Control-Level Power Outputs
The DS200DCFBG1B power supply board converts the input 38 V ac (±10%) or 24 V dc input into multiple stable DC outputs:
+5 V dc, 4 A: Provides core operating power for the main control board (SDCC/LDCC).
±15 V dc, 0.8 A each: Powers analog circuits and signal conditioning circuits.
±24 V dc: The +24 V dc output is rated at 3 A, and the -24 V dc output is rated at 1 A, used for driving relays and external loads.
All power supply outputs are protected with overcurrent protection, and fuse status is indicated via LEDs.
2. Voltage and Current Feedback Processing
The DS200DCFBG1B board integrates multiple voltage-controlled oscillator (VCO) circuits that convert analog signals into frequency signals for processing by the SDCC/LDCC main control board:
AC Line Voltage Feedback: Monitors the amplitude and phase sequence of the three-phase AC input voltage.
DC Bridge Voltage Feedback: Monitors the DC output voltage of the SCR bridge.
Motor Voltage Feedback: Monitors the actual voltage at the motor terminals.
Armature Current Feedback: Monitors armature current via shunts, supporting two independent channels.
Field Current Feedback: Monitors motor field current, supporting two independent channels.
These VCO circuits convert input voltages into frequency signals ranging from 0 to 500 kHz, which are sent to the main control board via the 1PL connector for closed-loop control and protection functions.
3. AC Line Monitoring and Synchronization
The board contains amplifier circuits that process AC line-to-line voltage signals. These signals are sent to the SDCC/LDCC board via the 1PL connector for:
Detecting power bridge SCR failures.
Generating synchronization signals for SCR firing.
Detecting phase loss and phase sequence errors.
DIP switches SW1, SW2, and SW3 are used to configure the input voltage range to accommodate drive systems with different voltage levels.
4. AC Line Current Transformer Interface
In some applications, the drive's AC input lines L1 and L3 are equipped with AC current transformers (ACCTs). The DS200DCFBG1B board uses switch SW7 to select the burden resistance based on the drive's rated current. The ACCT signals are used for:
Commutation failure detection.
AC instantaneous overcurrent (IOC) protection.
Current feedback monitoring.
5. Contactor Drive Circuits
The DS200DCFBG1B board includes relay K2, which serves as a pilot relay for the MD contactor. The SDCC/LDCC board drives the coil of this relay via the 1PL connector, and the MACPL connector provides a 24 V dc FET output for driving the MD contactor.
6. SCR Firing Control Circuits
The DS200DCFBG1B board contains a gate array circuit that controls the firing of the SCRs in the bridge based on control signals received from the SDCC/LDCC board via the 1PL connector. The gate array is programmed at power-up by a serial PROM. The 5 V outputs of the gate array are converted by gate pulse amplifier circuits into the power level required to drive the forward and reverse gate pulse transformers on the DS200PCCA Power Connect Card via the 5PL connector.
To prevent spurious firing signals, the firing power is removed from the gating circuits until the gate array is programmed and the 5 V power is in regulation.
7. Motor Voltage Attenuation Circuit
The DS200DCFBG1B board includes a motor voltage attenuation circuit that provides an analog representation of the motor voltage. This signal is sent to the SDCC/LDCC board via pin 6 of the 1PL connector. The attenuation circuit is biased at 2.5 V and can vary from 0 to 5 V depending on the motor voltage. DIP switch SW6 is used to scale the motor voltage feedback.
8. Power Supply Status Monitoring and Protection
The DS200DCFBG1B board provides the /PSEN signal (2PL-1). When the +5 V supply is in regulation, this signal is at a TTL low level. If the +5 V supply goes out of regulation, the signal goes high, triggering a microprocessor reset on the main control board (SDCC/LDCC).
III. Hardware Architecture
1. Board Structure
The DS200DCFBG1B board uses a standard printed circuit board structure with dimensions compatible with the board carrier of the DC2000 series drive systems. The board includes:
2. Power Input and Outputs
Input: 38 V ac (±10%) or 24 V dc.
Outputs: +5 V dc (4 A), ±15 V dc (0.8 A each), +24 V dc (3 A), -24 V dc (1 A), 115 V ac (protected by a 1/2 A fuse).
3. Protection and Indicators
Fuse FU1: Protects the 115 V ac output, 1/2 A, 2AG fast-acting.
Fuse FU2: Protects the +24 V, +15 V, and +5 V supplies, 7 A, 2AG fast-acting.
Fuse FU3: Protects the -24 V and -15 V supplies, 7 A, 2AG fast-acting.
LED CR51: Indicates FU2 is blown (red).
LED CR55: Indicates FU3 is blown (red).
Neon Lamp LT1: Indicates FU1 is blown.
4. Testpoints
| Testpoint | Description |
| P5 | Regulated +5 V dc supply (±5%) |
| DCOM | 0 V common reference point |
| P15 | Regulated +15 V dc supply (±5%) |
| N15 | Regulated -15 V dc supply (±5%) |
| ACCT | ACCT signal from DCFB to SDCC |
IV. Detailed Interface Description
1. Power and Control Interface (2PL)
The 2PL connector provides power and control signal connections between the DCFB board and the NTB/3TB, STBA, SLCC, and SDCC/LDCC boards:
| Pin | Signal | Description |
| 2PL-1 | /PSEN | Power supply enable (active low) |
| 2PL-2 | -15V | -15 V dc, ±5% |
| 2PL-3 | +15V | +15 V dc, ±5% |
| 2PL-4 | DCOM | Drive common |
| 2PL-5 | +5V | +5 V dc, ±5% |
| 2PL-6 | +5V | +5 V dc, ±5% |
| 2PL-7 | DCOM | Drive common |
| 2PL-8 | -24V | -24 V dc, ±20% |
| 2PL-9 | +24V | +24 V dc, ±20% |
2. Main Control Interface (1PL)
The 1PL connector is the primary communication interface between the DS200DCFBG1B board and the SDCC/LDCC main control board, transmitting VCO frequency signals, control signals, and status feedback:
| Pin | Signal | Description |
| 1PL-6 | FAN5 | Motor voltage #2 analog output |
| 1PL-8 | FIN0 | DC armature shunt #1 VCO output |
| 1PL-9 | FIN1 | Motor field current shunt #1 VCO output |
| 1PL-10 | FIN2 | DC armature shunt #2 VCO output |
| 1PL-11 | FIN4 | V1-V2 AC line voltage feedback |
| 1PL-12 | FIN5 | V1-V3 AC line voltage feedback |
| 1PL-13 | FIN6 | DC bridge voltage feedback |
| 1PL-16 | /ENREV | Enable reverse armature SCRs |
| 1PL-17 | /ENFWD | Enable forward armature SCRs |
| 1PL-18 | /FF2 | Field #2 SCR firing |
| 1PL-19 | /FF1 | Field #1 SCR firing |
| 1PL-29 | SYNC | AC line synchronization signal |
| 1PL-31 | /RST1 | System reset |
| 1PL-32 | FLD1CTRL | Field #1 control enable |
| 1PL-33 | FLD2CTRL | Field #2 control enable |
| 1PL-34 | MAC1 | MA contactor drive |
| 1PL-35 | MAC2 | MD contactor #1 drive |
| 1PL-36 | MAC3 | MD contactor #2 drive |
| 1PL-37 | VFBB | DC voltage feedback testpoint |
| 1PL-39 | FIN7 | Motor voltage feedback VCO output |
3. SCR Firing Interface (5PL)
The 5PL connector sends SCR firing signals to the DS200PCCA Power Connect Card:
| Pins | Signal | Description |
| 5PL-1 to 5PL-12 | A1F-A6F | Forward bridge SCR firing pulses |
| 5PL-13 to 5PL-24 | A1R-A6R | Reverse bridge SCR firing pulses (for reversing bridges only) |
| 5PL-2,4,6,8,10,12,14,16,18,20,22,24 | P24 | +24 V output |
4. AC Current Transformer Interface (1CPL)
The 1CPL connector connects to AC current transformers on phases L1 and L3:
| Pin | Signal | Description |
| 1CPL-1 | ACCT1 | L1 ACCT current input (white) |
| 1CPL-2 | ACCTCOM | L1 ACCT current input common (red) |
| 1CPL-3 | ACCTCOM | L3 ACCT current input common (red) |
| 1CPL-4 | ACCT3 | L3 ACCT current input (white) |
5. Contactor Control Interface (MACPL)
The MACPL connector provides MD contactor drive outputs:
| Pin | Signal | Description |
| MACPL-1 | MD1CTRL | MD #1 contactor control common output |
| MACPL-2 | MDCTRLPW | MD #1 contactor control 24 V dc output |
| MACPL-3 | MD2CTRL | MD #2 contactor control common output |
| MACPL-4 | MDCTRLPW | MD #2 contactor control 24 V dc output |
6. Stab Terminals
Stab terminals are used for connecting high-voltage signals:
| Terminal | Signal | Description |
| V1 | Phase A AC line voltage | Phase A |
| V2 | Phase B AC line voltage | Phase B |
| V3 | Phase C AC line voltage | Phase C |
| P1A | DC bridge positive voltage | Positive |
| P2A | DC bridge negative voltage | Negative |
| VM1A | Motor armature positive voltage | Positive (Generator field feedback) |
| VM1B | Motor armature negative voltage | Negative (Generator field feedback) |
| VM2A | Motor #2 armature positive voltage | Positive (Battery voltage feedback) |
| VM2B | Motor #2 armature negative voltage | Negative (Battery voltage feedback) |
V. Configuration and Settings
1. Jumper (JP) Configuration
Jumpers on the DS200DCFBG1B board are used to configure input signal sources, VCO circuit selection, and signal attenuation. Key jumper descriptions include:
| Jumper | Function | Position 1-2 | Position 2-3 |
| JP1 | AC line synchronization signal source | Generated by DCFB | Generated by TCCB (EX2000) |
| JP2 | AC contactor drop-out time delay | Normal (approx. 100 ms) | Minimum delay (manufacturing test) |
| JP3-JP7 | Armature shunt #1 configuration | Direct input | Rescaled for analog isolator |
| JP8-JP12 | Armature shunt #2 configuration | Direct input | Rescaled for analog isolator |
| JP13 | Shunt scaling (BKC and later) | For field supply shunt | For multibridge totalizing shunt |
2. DIP Switch (SW) Configuration
DIP switches are used to configure voltage ranges and current transformer burdens:
| Switch | Function | Description |
| SW1-SW3 | AC line voltage range | Settings 0-2, max 308-617 V ac (up to 1535 V with attenuators) |
| SW4 | DC bridge voltage feedback range | Same as above |
| SW5 | DC motor voltage feedback range | Same as above |
| SW6 | Motor voltage analog feedback range | Same as above |
| SW7 | ACCT burden selection | Settings 0-15, based on rated current and CT turns ratio |
Important Note: Factory settings for all jumpers and DIP switches are documented on the test data sheet supplied with each controller. When replacing a DS200DCFBG1B board, all jumpers and switches on the new board must be set to the same positions as on the board being replaced.
VI. Installation and Maintenance
1. Mounting Location
The DS200DCFBG1B board is normally mounted in the board carrier behind the drive control card (SDCC/LDCC), facing the front (for some EX2000 applications, it may be in a different location).
2. Replacement Procedure
Turn Off Power: Turn off all power to the drive, then wait several minutes for all power supply capacitors to discharge. Test any electrical circuits before touching them to ensure the power is off.
Open Cabinet Door: Open the equipment's cabinet door to access the printed wiring boards.
Release Lock Tabs: Pull the lock tabs located on either side of the board rack, then lift the front board carrier (with the drive control card) and tilt it forward and down to access the DCFB board.
Disconnect Cables: Carefully disconnect all cables from the DCFB board.
Release Plastic Snaps: Push back on the plastic snaps (holders) to release the DCFB board from the board carrier.
Verify Configuration: Verify that all jumpers and switches on the new (replacement) DCFB board are set in the same positions as on the old board.
Install New Board: Orient the new DCFB board in the same position as the one removed and install it onto the board carrier. Make sure all plastic snaps snap back into position to secure the board.
Reconnect Cables: Reconnect all cables to the DCFB board as labeled and ensure that the cables are properly seated at both ends.
Adjust EE Parameters: Perform the EE parameter adjustment procedure as required.
Close and Secure: Swing the front board carrier back up into position, slide the lock tab(s) on the side of the board rack back into the locking position, then close the drive cabinet door.
3. Maintenance Recommendations
Fuse Replacement: Fuses FU1, FU2, and FU3 are the only user-replaceable components on the DCFB board. If any other components fail, the board must be replaced as a unit.
Anti-Static Precautions: Always wear a grounded wrist strap when handling the board. Store the board in an anti-static bag when not in use.
Regular Inspections: Periodically check the status of LEDs and the neon lamp to ensure proper power supply operation.
Spare Parts Management: It is recommended to keep at least one identical DCFB board on-site as a spare to minimize downtime in case of failure.
VII. Fault Diagnostics
1. LED and Neon Lamp Indications
| Indicator | Indicates When Lit |
| CR51 (Red LED) | Fuse FU2 (+24 V line to +15 V regulator) is blown |
| CR55 (Red LED) | Fuse FU3 (-24 V line to -15 V regulator) is blown |
| LT1 (Neon Lamp) | Fuse FU1 (115 V ac line) is blown |
2. Common Faults and Troubleshooting
| Fault Symptom | Possible Cause | Recommended Action |
| FU2 repeatedly blows | Accidental short of +24 V dc | Check for probing errors or wiring issues at terminal board |
| FU3 repeatedly blows | Accidental short of -24 V dc | Check for probing errors or wiring issues at terminal board |
| FU1 blows | Overload or short circuit on 115 V ac load | Check fan loads or external devices |
| /PSEN high | +5 V power supply out of regulation | Check FU2 status; DCFB board may need replacement |
| No VCO output | Input signal or configuration error | Check jumper and DIP switch settings |
VIII. Applications
The DS200DCFBG1B power supply board is widely used in the following industrial applications:
DC2000 DC Drive Systems: Provides control power and feedback processing for DC motor drives.
CB2000 Digital Control Systems: Serves as a core power supply and signal conditioning module.
EX2000 Excitation Systems: Used for generator excitation control, providing power and feedback processing.
FC2000 Frequency Control Systems: Provides control and protection functions in variable frequency drive systems.
GF2000 Generator Control Systems: Used for generator excitation and protection.
ME2000 Motor Control Systems: Provides power and signal conditioning in motor control applications.
AC2000 IGBT Drive Systems: Provides control-level power in AC drive systems.
