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| Place of Origin | Germany |
| Brand Name | SIEMENS |
| Certification | CE ROHS |
| Model Number | C98043-A7002-L4 6RY1703-0DA02 |
Part Number: C98043-A7002-L4
Alternate Order Number: 6RY1703-0DA02
Manufacturer: Siemens AG (Germany)
Product Type: Power Interface Board (PIB) — Includes Terminals
The C98043-A7002-L4 is the base Power Interface Board for the Siemens SIMOREG DC-MASTER 6RA70 DC drive series — supplied complete with its terminal block assembly.
In the 6RA70's electronics architecture, this board provides the critical connection layer between the digital control electronics and the thyristor power section: it translates digital firing angle commands from the CUD1 control board into precise thyristor gate pulses, monitors the power section for fault conditions, and acquires the analogue voltage and current measurements that the control loops depend on.
The C98043-A7002-L4 is supplied with its terminal assembly — the screw terminal blocks that carry the measurement signal and control wiring connections from the power section to the board.
This distinction is important when ordering: some variants of the power interface board are supplied without terminals, while the L4 designation here specifies the board with complete terminals included.
For a like-for-like replacement, the terminal-equipped version ensures that all wiring connections can be directly transferred from the old board to the new one without sourcing terminals separately.
The cross-reference 6RY1703-0DA02 is the Siemens market-facing spare part order number for this board. Both numbers — C98043-A7002-L4 and 6RY1703-0DA02 — refer to the same assembly and can be used interchangeably when sourcing.
| Parameter | Value |
|---|---|
| Part Number | C98043-A7002-L4 |
| Alternate Order No. | 6RY1703-0DA02 |
| Manufacturer | Siemens AG |
| Product Type | Power Interface Board (PIB) with Terminals |
| Product Family | SIMOREG DC-MASTER 6RA70 |
| Includes | Terminal block assembly |
| Core Functions | Thyristor firing, safety monitoring, voltage acquisition |
| Country of Origin | Germany / Romania |
In the SIMOREG 6RA70 electronics box, the Power Interface Board is connected to the rest of the drive via several types of connections: ribbon cable connectors to the CUD1 board, and screw terminal blocks to which the field wiring from the power section is connected. Measurement signals from voltage dividers on the power buswork, gate drive cables to the thyristor modules, and synchronisation signals from the AC supply all arrive at the PIB through its terminal assembly.
When the C98043-A7002-L4 is supplied with terminals, the terminal block hardware is included with the board.
This matters when replacing an old board where the terminal blocks have corroded, sustained physical damage, or where individual screw terminals have been stripped through repeated servicing.
The new board arrives with fresh terminals ready to accept the drive's field wiring, and the technician can transfer wires directly from the old terminal positions to the matching positions on the replacement board.
The terminal assembly is also important for correct installation.
Terminal block positions and labelling must match the wiring documentation for the specific 6RA70 configuration. A board supplied without the correct terminal assembly requires separate terminal sourcing and installation, adding time and potential for errors during a drive repair.
The armature converter in the SIMOREG 6RA70 is a three-phase fully controlled thyristor bridge. For a single-quadrant (motoring-only) drive, this is a six-pulse B6C bridge. For a four-quadrant drive capable of regenerative braking, two antiparallel B6 bridges form the antiparallel bridge (B6A) configuration.
In both cases, six thyristors (or twelve in the four-quadrant configuration) must be fired in the correct sequence and at the correct phase angle relative to the AC supply.
The C98043-A7002-L4 generates these firing pulses.
It continuously detects the zero crossings of the three-phase AC supply voltage — establishing the phase reference for firing angle calculation. Received firing angle commands from the CUD1 are translated into pulse timing relative to these zero crossings.
A dedicated pulse transformer or optocoupler isolates each firing pulse from the control circuitry before it reaches the thyristor gate.
For a four-quadrant drive, the PIB manages the changeover between the positive and negative bridge — suppressing firing pulses to the active bridge, verifying current extinction, then enabling the opposing bridge in a controlled sequence.
This bridge changeover must be handled with precise timing to avoid shoot-through faults between the two antiparallel bridges.
The SIMOREG DC-MASTER 6RA70 has been one of the most successful Siemens DC drive platforms. Its combination of digital control precision, wide power range (6 kW to 2500 kW), comprehensive fieldbus connectivity, and modular hardware made it the default choice for DC drive installations across multiple industrial generations.
The platform covered a broader power range than almost any comparable AC drive of its era.
Many 6RA70 installations still run continuously in heavy industry. These drives were designed and built for decades of service life. As the 6RA70 transitions fully into its end-of-life phase, reliable access to spare parts — including the C98043-A7002-L4 PIB — is the primary enabler of continued operation.
Facilities operating multiple 6RA70 units in critical processes typically hold at least one PIB in spare stock, given the direct downtime consequence of a PIB failure and the potential for multi-week sourcing lead times in the aftermarket.
Q1: The C98043-A7002-L4 and C98043-A7002-L4-13 are both listed as power interface boards for the same drive. What is the difference, and are they interchangeable?
The base part number C98043-A7002-L4 refers to the Power Interface Board with terminals as a base ordering entity. The -13 suffix in C98043-A7002-L4-13 identifies a specific production revision within the L4 family.
All revision suffixes within the L4 series (including -8, -9, -11, -12, -13) are functionally and mechanically interchangeable.
They serve the same function, fit in the same position, and connect via the same interfaces.
The revision number only distinguishes the specific component generation of the board, not its electrical function.
Q2: The SIMOREG 6RA70 drive shows fault F002 (armature overcurrent) during starting of a large DC motor. After clearing and re-trying, it trips again at approximately the same current level. Is the C98043-A7002-L4 the likely cause?
F002 during starting at a repeatable current level can indicate either a thyristor fault (one or more thyristors not firing correctly, forcing the remaining thyristors to carry excess current) or a PIB fault causing incorrect firing angle or missing pulses.
Before replacing the PIB, check the armature current waveform on an oscilloscope — an asymmetric waveform with one phase significantly lower than the others indicates a thyristor or gate circuit fault.
A symmetric waveform with the total current simply exceeding the limit more rapidly than expected may indicate a motor or load issue rather than a drive fault.
Q3: What is the expected service life of the C98043-A7002-L4 board in normal 6RA70 operation?
The PIB board contains passive components (capacitors, resistors, transformers, optocouplers) whose service life under normal industrial conditions typically exceeds 15–20 years. Boards in environments with high ambient temperatures, heavy vibration, or corrosive atmospheres may age faster.
The board's pulse transformers and gate drive optocouplers are the most likely components to degrade with age.
On high-run-hour drives, boards approaching 15–20 years of continuous service may be worth proactive replacement during a planned maintenance window, even without an active fault — particularly if the drive is in a critical process where unplanned downtime is costly.
Q4: The drive is a 6RA70 four-quadrant (regenerative) converter. The armature current waveform shows a notch or distortion at the bridge changeover transition. Is this a C98043-A7002-L4 fault?
Current waveform distortion at bridge changeover can result from incorrect bridge changeover timing or logic in the PIB.
The bridge changeover sequence — pulse suppression on the active bridge, current extinction detection, delay, then pulse enable on the opposite bridge — is coordinated by the PIB in conjunction with the CUD1.
If the changeover logic on the PIB has a component-level fault affecting the suppression or enable signals, distorted changeover transitions result.
Confirm with SIMOREG's internal oscilloscope function whether the bridge changeover sequence completes correctly before concluding a board fault.
Q5: When ordering the C98043-A7002-L4, should the terminal blocks be re-used from the old board or should fresh terminals always be specified?
The C98043-A7002-L4 includes terminals — this is part of the board's specification.
When receiving the replacement board, inspect the included terminal blocks for physical condition. Fresh terminal blocks are preferable where available and represent the cleanest installation.
However, if the original drive's terminal blocks are in excellent condition and carry well-documented wiring labels, transferring the blocks to the new board is acceptable.
In either case, torque all terminal screws to the specified value during installation — under-torqued terminals are a common cause of intermittent signal faults in drive maintenance.
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