Siemens SIMOREG K 6SC98 Series Modules - 6SC9833-0BG20

Technical Dossier

Product Details And Specifications

Siemens SIMOREG K 6SC98 Series Technical Notes

The Evolution of SIMOREG K 6SC98 Architecture

The SIMOREG K platform was introduced by Siemens in the 1980s as a modular DC drive solution designed for integration into centralized control architectures. Early variants operated with analog control boards and discrete thyristor firing circuits. The 6SC98 numbering convention encodes the functional role of each board: the third and fourth digits identify the board type (e.g., 33 for rectifier trigger boards, 50 for control electronics), while the suffix codes define the current rating and hardware revision.

Through the 1990s, Siemens progressively introduced digital firing angle control and improved EMC shielding, reflected in revised suffix codes (e.g., -0BG20 vs. earlier -0BF variants). Communication interfaces evolved from hardwired analog setpoints to serial links compatible with SIMATIC S5 and later S7 PLCs. By the early 2000s, Siemens transitioned its DC drive portfolio toward the SIMOREG DC Master (6RA70 series), which offered fieldbus integration (PROFIBUS-DP) and significantly expanded diagnostic capability. The 6SC98 series entered end-of-life status progressively between 2005 and 2012, with spare parts support officially discontinued for most variants.

SIMOREG K 6SC98 Full Catalog & Functionalities (SKU List)

The following SKUs represent confirmed modules within the Siemens SIMOREG K 6SC98 series. Each entry reflects a distinct functional role within the drive system architecture.

Rectifier & Trigger Boards

• 6SC9833-0BG20: Rectifier trigger board; generates thyristor firing pulses for the main converter bridge.
• 6SC9833-0BF20: Earlier revision rectifier trigger board; predecessor to -0BG20 with analog firing angle control.
• 6SC9833-0BG40: High-current variant rectifier trigger board for larger drive cabinets.
• 6SC9833-0BF40: Analog-control rectifier trigger board, high-current rating.

Control & Regulation Electronics

• 6SC9850-0AC00: Main control board; handles speed regulation loop and setpoint processing.
• 6SC9850-0AC10: Revised control board with improved analog input filtering.
• 6SC9850-0AC20: Control electronics board with extended diagnostic output signals.
• 6SC9860-0AA00: Supplementary regulation board; field current control for separately excited DC motors.
• 6SC9860-0AA10: Revised field regulation board with improved thermal protection logic.

Interface & Adapter Boards

• 6SC9811-0AC00: Terminal expansion board; extends analog and digital I/O connectivity.
• 6SC9811-0AC10: Revised terminal board with additional relay output contacts.
• 6SC9820-0AA00: Pulse encoder interface board; connects incremental encoders for closed-loop speed feedback.
• 6SC9820-0AA10: Encoder interface board with differential input support.

Power Supply Boards

• 6SC9840-0AC00: Internal SMPS board; supplies logic and control voltages to the drive electronics.
• 6SC9840-0AC10: Revised power supply board with improved short-circuit protection.
• 6SC9840-0AC20: High-stability power supply board for environments with significant mains voltage fluctuation.

Sourcing Hard-to-Find & Obsolete SIMOREG K 6SC98 Parts

For plant maintenance teams operating under capital expenditure constraints, DriveKNMS provides the following lifecycle extension support:

Facilities that have extended SIMOREG K system operation by 5–10 years through structured spare parts management report total maintenance costs 60–80% lower than equivalent drive replacement projects. The critical variables are: maintaining at least one spare rectifier trigger board (6SC9833 series) and one spare control board (6SC9850 series) per drive cabinet, and scheduling electrolytic capacitor inspection on power supply boards every 36 months.

Quality Control for the SIMOREG K 6SC98 Range

The 6SC98 series presents specific reliability risks associated with age and storage conditions. DriveKNMS applies a five-stage inspection protocol to all units before dispatch:

1. Visual and mechanical inspection: PCB surface examination for corrosion, cracked solder joints, damaged traces, and connector pin condition. Backplane connector pins on 6SC98 boards are a known wear point and are inspected under magnification.
2. Electrolytic capacitor assessment: All electrolytic capacitors on power supply and control boards are measured for capacitance and ESR. Units with capacitors outside ±20% of rated capacitance are flagged for recapping before dispatch.
3. Thyristor firing circuit verification: For rectifier trigger boards (6SC9833 series), firing pulse timing and symmetry are verified using a dedicated test rig that simulates the drive's synchronization input signals.
4. Functional power-up test: Boards are powered under controlled conditions and output signals are measured against Siemens reference values from the original service documentation.
5. Hardware revision logging: The exact PCB revision and suffix code are recorded and included in the dispatch documentation, enabling the receiving engineer to confirm compatibility before installation.