The IS200RCSAG1A is an RC Snubber Board designed by General Electric (GE) for its Innovation Series™ 1800/1000 frame non-regenerative sources. This board is the standard version within the RCSA series, primarily used to provide snubber circuitry for the SCR/diode modules in the power bridge, protecting the power devices from voltage overshoots during commutation.
The IS200RCSAG1A board is used in non-regenerative sources with one board per phase, mounted directly on the power devices. The board features two sets of connection points for SCR (cathode) and diode (anode) to accommodate the physical layout differences between the 1800 and 1000 frame units. The board can be used with AC inputs up to 660 VLL rms.
Key features of the IS200RCSAG1A include:
Dedicated for 1800/1000 Frames: Suitable for high-power frames of Innovation Series non-regenerative sources.
One Board per Phase: Each non-regenerative source uses three RCSA boards for the U, V, and W phases respectively.
Snubber Protection: Protects SCR/diode modules from voltage overshoots between devices during commutation.
Noise Isolation: Isolates the gate drive circuit from unwanted noise.
Direct Mounting: Board mounts directly onto the SCR/diode modules, secured via terminal connections.
Dual Connection Sets: Provides two sets of SCR and diode connections to accommodate the physical layout of different frames.
Passive Design: The board has no fuses, test points, LED indicators, or adjustable hardware, ensuring high reliability.
High Voltage Capability: Can withstand snubber terminal clamping voltages up to 616 V.
The board mounts directly onto the power devices, secured to the SCR/diode module terminals via four eyelet connections. Four holes are located at the corners of the board for securing wires with ties. A cutout is also provided for the SCR gate and cathode connector (labeled SCRPL).
II. Main Functions
The primary functions of the IS200RCSAG1A include, but are not limited to, the following:
1. Voltage Overshoot Protection
During commutation of SCR/diode modules, parasitic inductance and capacitance between devices can cause voltage overshoots. The RC snubber circuit on the IS200RCSAG1A board absorbs this overshoot energy through its resistor-capacitor network, limiting the rate of voltage rise and protecting the power devices from damage.
2. Commutation Snubbing
The snubber circuit provides a low-impedance path when the device turns off, dissipating energy stored in parasitic inductances, thereby smoothing the voltage waveform and reducing electromagnetic interference. Each RCSA board has two independent RC snubber circuits, corresponding to the SCR and diode in a phase arm.
3. Noise Isolation
The IS200RCSAG1A board also helps isolate the gate drive circuit from high-frequency noise generated by the main power circuit, ensuring the integrity and reliability of gate drive signals.
4. Physical Layout Adaptation
The board features two sets of connection points to accommodate the different physical layouts of the 1800 and 1000 frames:
E1: Diode anode connection.
E3: SCR anode and diode cathode connection.
E4: SCR cathode connection.
This design allows a single board to be used for two different frame sizes, simplifying spare parts management.
5. High Voltage Capability
The snubber terminals on the IS200RCSAG1A board can withstand clamping voltages up to 616 V, making it suitable for systems with AC input voltages up to 660 VLL rms.
III. System Applications
1. Application in Innovation Series Non-regenerative Sources
The IS200RCSAG1A is a critical board for protecting power devices within Innovation Series 1800/1000 frame non-regenerative sources. Its roles within the system include:
Power Device Protection: Absorbs voltage overshoots during commutation of SCR/diode modules, preventing device damage.
Electromagnetic Interference Suppression: Smooths voltage waveforms, reducing EMI generated during commutation.
Gate Drive Isolation: Isolates the gate drive circuit from high-frequency noise generated by the main power circuit.
2. Coordination with AC Line Filter
In addition to the snubber circuits on the RCSA board, each non-regenerative source uses a separate AC line filter mounted outside the power cabinet. Both work together to ensure safe operation of the power devices and system electromagnetic compatibility.
3. Adaptation for 1800 and 1000 Frames
The IS200RCSAG1A board provides two sets of connection points, making it suitable for both the 1800 and 1000 frames. This design simplifies spare parts management and reduces inventory variety. Users must select the appropriate connection points based on the actual frame during installation.
4. Typical Application Scenarios
Industrial High-Power Non-regenerative Sources: Used in various industrial applications requiring high-power rectification or inversion.
Motor Drive Systems: Protects power devices in rectifier and inverter bridges within AC variable frequency drives.
Power Conversion Systems: Used in power conversion equipment such as DC power supplies and UPS systems.
Rail Transit Traction Systems: Protects power devices in traction converters.
Renewable Energy Systems: Applied in converters for wind power and photovoltaic generation.
IV. Detailed Interface Description
1. Connection Points
The IS200RCSAG1A board features three stab-on connection points for connecting to the SCR/diode modules:
| Connection Point | Description |
| E1 | Diode anode connection |
| E3 | SCR anode and diode cathode connection |
| E4 | SCR cathode connection |
2. Board Fixing Eyelets
Four eyelet connection points at the corners of the board are used to secure the board to the SCR/diode module terminals. Nuts and washers are used for fixing, with a torque requirement of 13 in-lbs.
3. Wire Fixing Holes
Four holes are located at the corners of the board. Wires connected to the board can be secured to these holes using cable ties to prevent loosening or vibration.
4. SCR Gate Connection Cutout
A cutout is provided on the board for the SCR gate and cathode connector (labeled SCRPL), facilitating easy connection of the gate drive cable.
V. Installation and Replacement
1. Mounting Location
The IS200RCSAG1A board mounts directly onto the SCR/diode modules. One RCSA board is installed on the power module for each phase arm. The board connects to the power module terminals via its connection points and is secured through four eyelets.
2. Replacement Procedure
Safety Warnings:
WARNING: To prevent electric shock, turn off power to the drive system and follow all local Lock-Out/Tag-Out safety practices.
CAUTION: Use safety test equipment designed for high voltages to confirm circuits are de-energized and discharged before touching them.
CAUTION: To prevent component damage caused by static electricity, treat all boards with static sensitive handling techniques. Wear a grounding strap and store boards in anti-static bags.
Replacement Steps:
Verify Power Off: Ensure the drive system is completely de-energized and follow local Lock-Out/Tag-Out procedures.
Open Cabinet Door: Open the power cabinet door. Use high-voltage test equipment to verify circuits are de-energized and discharged.
Cut Wire Ties: Cut and remove any wire ties that secure wires to the holes located at the corners of the board.
Remove Nuts: Remove the four nuts and washers at the eyelet connections that secure the RCSA board to the SCR/diode module terminals (see Figure 1 for eyelet connection/nut locations).
Remove Old Board: Remove the old RCSA board from the SCR/diode module terminals.
Install New Board:
Orient the new RCSA board in the same position as the one removed and install it onto the SCR/diode module terminals.
Secure the new board to the terminals with the four nuts and washers removed in step 4, torquing them to 13 in-lbs.
Re-secure any wires that were cut loose from the board's corner holes in step 3 with new cable ties.
Close Cabinet Door: Close the power cabinet door after confirming everything is correct.
