GE IS200JPDCG1A Power Distribution Board

The IS200JPDCG1A is a Power Distribution Board designed by General Electric (GE) for its Mark VIe™ Gas Turbine Control System. This board is the core component of the IS2020JPDC Power Distribution Module, primarily responsible for distributing 125 V dc, 115/230 V ac, and 28 V dc power to other boards within the control system, providing centralized management and distribution of system power.

The IS200JPDCG1A board is mounted on a steel base within the JPDC module. The module dimensions are 6.75 inches × 19.0 inches (17.2 cm × 48.26 cm). The board integrates various power input and output connectors, fuse protection, toggle switches, diagnostic feedback circuits, and test points, providing a complete power distribution solution for the Mark VIe control system.

IS200JPDCG1A and later revisions include a signal isolation transformer added to the diagnostic signal path A5 (AC1 feedback magnitude). This provides galvanic isolation between FE/PE and the AC line connection JAC. This improvement results in a ±15% tolerance in the AC1 feedback signal reading displayed in the ToolboxST application.

Key features of the IS200JPDCG1A board include:

• Multiple Voltage Level Distribution: Supports power distribution for three voltage levels: 125 V dc, 115/230 V ac, and 28 V dc.

• Redundant Input Support: Can accept two battery inputs and one DACA module input for 125 V dc power.

• TMR Support: Supports both Triple Modular Redundant (TMR) and simplex configurations for 28 V dc power.

• Comprehensive Protection: Input and output circuits are protected by fuses or polyfuses.

• Diagnostic Feedback: Provides extensive power status diagnostic signals via the PPDA I/O pack.

• Test Points: Offers 8 test points for convenient on-site measurement of key voltages.

• Flexible Configuration: Jumpers allow configuration for 125 V dc ground detection and 28 V dc simplex/redundant modes.

• Daisy Chain Expansion: A 50-pin ribbon cable connects to other distribution boards to expand diagnostic capability.

  
  

II. Main Functions

The primary functions of the IS200JPDCG1A include, but are not limited to, the following:

1. 125 V dc Power Distribution

The board accepts two battery inputs (via connectors JD1 and JD2) and one 125 V dc input from a DACA module (via connector JZ2). Each input is typically routed through an external filter. The two battery inputs are OR'ed together by diode module D1 and are OR'ed with the 125 V dc from the DACA module, forming a 125 V dc bus labeled PDC. The return paths of all 125 V dc inputs are connected together and labeled NDC. The total 125 V dc current should not exceed 20 amps.

All three 125 V dc inputs are floating with respect to ground. When jumper JP2 is installed, each side of the 125 V dc bus is connected to FE ground through approximately 84 kΩ of resistance, providing a means of ground fault detection.

2. 115/230 V ac Power Distribution

The board accepts 115 V ac or 230 V ac input via the JAC connector, with a maximum allowable current of 12.5 A rms. The low or neutral side of the input power is expected to be grounded. Two AC outputs are provided, both protected by a 10 A time-delay fuse on the high side only (Pin 1 of each connector). The output at JAC1 is controlled by toggle switch SWAC1; the JAC2 output is not switched.

3. 28 V dc Power Distribution

The board supports TMR or simplex 28 V dc power distribution. Three separate 28 V input connectors, JR, JS, and JT, are provided. On each connector, two pins are paralleled to increase current-carrying capacity.

• Eight unfused output connectors: J1, JP1, JCR, JCS, JCT, JRS, JSS, JTS. Output current should not exceed 12.5 A.

• Twenty-six outputs with 1.6 A polyfuse protection: In TMR configuration, ten of these (JR1-JR10) provide 28PR power, eight provide 28PS power, and eight provide 28PT power.

• One output (P4) with 0.5 A polyfuse protection: Powers the PPDA I/O pack. In response to overcurrent, the polyfuse latches off; cycle power to reset it.

4. 125 V dc Outputs to External 125 V dc/28 V dc Power Supplies

Outputs JIR, JIS, and JIT provide power to three external 125 V dc input / 28 V dc output power supplies. These outputs are fuse-protected and controlled by toggle switches SW1R, SW1S, and SW1T. Two power source selection options are provided:

• Normal Mode: A shorting plug inserted in connector JDB selects 125 V dc power from the entire P125 bus (fed by both battery inputs and the DACA input).

• Alternate Mode: Moving the shorting plug to connector JDA selects power for JIR, JIS, and JIT from Battery A only, allowing a lower-rated AC/DC converter to supply only the other 125 V dc outputs.

5. Other 125 V dc Outputs

• J7A, J7B, J7C Outputs: Fuse-protected and controlled by toggle switches, they provide output power to the TRLY Relay Output terminal board and similar boards.

• J8A, J8B, J8C Outputs: Fuse-protected only, with a 22 W resistor inserted in series with each side to limit output power. These supply power to boards like the TBCI Contact Input terminal board, which require a source with limited short-circuit capability to meet agency requirements.

6. Diagnostic Feedback Signals

The IS200JPDCG1A board provides power distribution feedback signals to the IONet via the PPDA I/O pack. The PPDA I/O pack mounts on the JPDC module. Diagnostic signals include:

Feedbacks also include an electronic ID identifying the board type, revision, and serial number.

7. Test Points

The board features 8 test points for convenient on-site measurement of key voltages:

III. System Applications

1. Application in Mark VIe Control System

The IS200JPDCG1A is the core power distribution board within the Mark VIe control system, providing multiple voltage level power to various boards in the system. Its roles include:

• Central Power Distribution: Distributes incoming 125 V dc, 115/230 V ac, and 28 V dc power to different parts of the control system.

• Redundant Power Management: Supports two battery inputs and a DACA module input, achieving redundant power supply through OR-ing logic.

• TMR Power Support: Provides independent 28 V dc power distribution for triple modular redundant systems.

• Diagnostics and Monitoring: Provides power status feedback to the IONet via the PPDA I/O pack, enabling remote monitoring and fault diagnosis.

2. Coordination with the PPDA I/O Pack

The PPDA I/O pack mounts on the JPDC module and connects to the IS200JPDCG1A board via the JA1 connector. It is responsible for collecting power distribution feedback signals and transmitting them over the IONet to the control system. In a JPDC-based PDM system, the PPDA I/O pack must be mounted on the JPDC.

3. Daisy Chain Expansion

Via the 50-pin ribbon cable on connector P2, the JPDCG1A can be daisy-chained with other distribution boards (such as JPOM). This allows diagnostic signals from up to four additional boards to be routed to the JPDC for unified collection by the PPDA I/O pack. When daisy-chained, the next available position will be two groups higher.

4. Typical Application Scenarios

• Gas Turbine Control Systems: Provides power distribution for various boards within the Mark VIe control system.

• Steam Turbine Control Systems: Acts as a power distribution center, supplying I/O boards, relay boards, etc.

• Combined Cycle Power Plants: Provides centralized power management in DCS or PLC control systems.

• Industrial Turbine Control: Offers reliable power distribution for critical control applications requiring redundant power.

  
  

IV. Detailed Interface Description

1. AC Input and Output Connectors

2. 125 V dc Input Connectors

3. 125 V dc Output Connectors

4. 28 V dc Input and Output Connectors

5. Diagnostic and Control Interfaces

6. Toggle Switches

7. Test Points

V. Configuration and Operation

1. 28 V dc TMR Configuration

Separate 28 V dc power inputs are received through connectors JR, JS, and JT. The positive sides of the three inputs are connected to separate power buses, designated as 28PR, 28PS, and 28PT respectively. The return sides of the three inputs are connected together and designated as 28N. Output power is distributed from the three buses through separate R, S, and T output connectors.

2. 28 V dc Simplex Configuration

One, two, or three 28 V dc power inputs can be received through connectors JR, JS, and JT. The three power buses can be connected into a single bus by inserting jumpers between terminals 1, 2, and 3 of terminal board TB1. All output connectors are fed from this single 28 V dc bus.

3. Configuration of 125 V dc Outputs to External Power Supplies

The source for outputs JIR, JIS, JIT is selected by the position of shorting plugs on JDA and JDB:

• JDB Inserted: Normal mode, power taken from the entire P125 bus (fed by both battery inputs and the DACA input).

• JDA Inserted: Alternate mode, power taken from Battery A only.

Important Warning: Never jumper connectors JDA and JDB at the same time!

4. Ground Fault Detection Configuration

Jumper JP2 configures ground fault detection for the 125 V dc bus:

• JP2 Installed: Each side of the 125 V dc bus is connected to FE ground through approximately 84 kΩ resistors, providing a means of ground fault detection.

• JP2 Removed: The 125 V dc bus is floating with respect to ground, impedance >1500 kΩ.

5. Switch Operation Precautions

When switches SW1R, SW1S, and SW1T are turned OFF, wait at least 30 seconds before turning them back ON. This prevents damage to the input circuits of the 28 V dc power supplies.

VI. Installation and Replacement

1. Mounting Location

The JPDC module is typically mounted vertically, with the 115/230 V ac input connector (JAC) at the bottom. It is attached with four screws using mounting holes located at the top and bottom of the module base. Distribution boards are usually mounted low in the cabinet to facilitate grounding.

2. Grounding Requirements

The Mark VIe control system divides ground into Protective Earth (PE) and Functional Earth (FE):

• PE Ground: Must be connected to an appropriate earth connection in accordance with all local standards. The minimum grounding must be capable of carrying 60 A for 60 seconds with no more than a 10 V drop.

• FE Ground: Must be bonded to the PE ground system at one point.

FE circuitry on the JPDC board is grounded through metal mounting supports fastened to the underlying sheet metal of the module. The metal switch bodies on the board are tied to PE circuitry. Separate ground wires from the JPDC module, via screw connections E5 and/or E6, must be connected to the enclosure PE bus.

3. Replacement Procedure

Important Note: To replace a JPDC, replace the entire module. Do NOT remove the board from its mounting plate.

Safety Warnings:

• Prior to replacing terminal boards, ensure all Lockout/Tagout procedures are followed.

• Treat all boards with static sensitive handling techniques. Wear a wrist grounding strap and store boards in anti-static bags.

Replacement Steps:

1. Lockout/Tagout: Lockout and/or tagout all energy sources to the module.

2. Verify Power Off: Check the voltage on each terminal to ensure no voltage is present.

3. Record Configuration: Note the orientation of the module and the location of any jumped connections. Verify labels and unplug all connectors.

4. Remove Ground Wires: Unscrew and remove the board grounding wires.

5. Remove Mounting Hardware: Remove the hardware used to fasten the module to the cabinet.

6. Inspect New Module: Inspect the new module for shipping damage.

7. Install New Module: Install the new module into the cabinet in the same orientation as the old module.

8. Verify Jumpers: Verify all jumped connections on the new module are the same as those on the old module.

9. Reconnect Ground Wires: Reconnect the board grounding wires.

10. Reconnect Connectors: Reconnect all wire and cable connectors.

11. Restore Power: Remove the Lockout/Tagout and restore power to the module.

12. Functional Test: Test/verify that all switches, fuses, LEDs, and I/O packs function properly.