Board C98043-A7002-L1 6RY1703-0DA01 Power Interface Board C98O43-A7OO2-L1 6RY17O3-ODAO1 6RY1 703-0DA01

Siemens C98043-A7002-L1 | SIMOREG DC-MASTER 6RA70 Power Interface Board with Terminals — 6RY1703-0DA01

Part Number: C98043-A7002-L1

Market Order Number: 6RY1703-0DA01

Manufacturer: Siemens AG (Germany)

Product Type: Power Interface Board (PIB) — Includes Terminals

Product Family: SIMOREG DC-MASTER 6RA70 Series

Drive Application: DC motor speed control, 6 kW to 2500 kW 

Overview

The C98043-A7002-L1 is the L1-series Power Interface Board for the Siemens SIMOREG DC-MASTER 6RA70 DC drive platform, supplied complete with its terminal assembly and orderable under the market-facing reference 6RY1703-0DA01.

This board is the critical hardware link between the 6RA70's digital control unit (CUD1) and the thyristor power section that actually controls the DC motor's armature current and speed.

In the SIMOREG 6RA70 electronics architecture, the Power Interface Board performs three core functions simultaneously. It generates and distributes the precisely-timed thyristor firing pulses that determine the drive's armature output voltage.

It monitors the power section continuously for fault conditions — overcurrent, overvoltage, and thyristor anomalies. And it acquires the analogue measurement signals from the power section, including armature current feedback and supply voltage, routing these to the control board's measurement inputs for the closed-loop control algorithms.

The market order number 6RY1703-0DA01 is the Siemens-published spare parts reference for this assembly and is the number used when ordering through official Siemens service channels or the industrial aftermarket.

The internal component designation C98043-A7002-L1 appears on the board's own label and is how the board is identified when it's already installed in a drive. Both numbers refer to the same physical assembly.

Key Specifications

L1 Series vs L4 Series — Variant Differences

The C98043-A7002 Power Interface Board series spans multiple variants, designated L1 through L4. The L-suffix indicates design generations of the same board function. L1 and L4 are the two most commonly encountered variants in the 6RA70 installed base.

The L1 series represents an earlier generation of the PIB, designed for 6RA70 drives built during the initial production years of the platform.

The L4 series incorporates later design refinements. 

Both serve the same fundamental function: thyristor firing, safety monitoring, and measurement acquisition. However, the two series are not directly interchangeable — the specific sub-circuits and component layouts differ between L1 and L4, and connector configurations may vary.

When ordering a replacement PIB, confirm the L-variant against the original installed board's label to ensure the correct series is sourced. Installing an L4 where an L1 is required — or vice versa — may result in connection mismatches or incorrect circuit behaviour.

SIMOREG 6RA70 — Platform Overview

The SIMOREG DC-MASTER 6RA70 was Siemens' flagship fully digital DC drive platform, covering armature currents from 15A to over 3000A and motor powers from a few kilowatts to several megawatts.

It became the standard DC drive solution for the most demanding industrial applications: steel rolling mills, paper machines, mine hoists, ship propulsion, printing presses, large test stands, and continuous process lines.

The 6RA70's two powerful microprocessors handle all drive control functions — speed and current regulation, field weakening, communications, and protection — in software. Drive control functions are interconnectable by parameters, giving the 6RA70 exceptional application flexibility without hardware modification.

The C98043-A7002-L1 PIB is the hardware that makes the control software's firing angle commands physically real in the power stage.

Installation with Terminals

The C98043-A7002-L1 is supplied with its terminal blocks. These screw terminal blocks carry all the wiring connections from the power section to the board: gate drive cables to the thyristor modules, current measurement signals from the shunt or current transformers, and AC supply synchronisation signals.

All wires terminate at the board's screw terminals, and the terminal assembly itself is part of what makes this replacement complete.

During board replacement, wires should be labelled or photographed before removal from the old board's terminals. The terminal positions on the replacement board match the original, allowing direct transfer of labelled wires.

All terminal screws should be torqued to the specified value — under-torqued terminals are a leading cause of intermittent measurement signal faults in maintained drives.

FAQ

Q1: The SIMOREG 6RA70 shows fault F001 (supply voltage fault) on startup with confirmed AC supply present at the drive input. Could the C98043-A7002-L1 be the fault source?

Yes — F001 is generated when the PIB's zero-crossing detection circuit cannot synchronise to the AC supply phase voltages.

The zero-crossing detection is on the C98043-A7002-L1, so a failure in this circuit produces F001 even with a healthy AC supply. 

Before replacing the board, verify the supply connections to the PIB's terminal blocks and check for damaged signal leads.

If wiring is intact and F001 persists, the board's sync circuit is the most likely fault.

Q2: A replacement C98043-A7002-L1 has been installed. The drive starts without fault but the armature current waveform on an oscilloscope shows an asymmetric shape with one phase significantly lower. What does this indicate?

An asymmetric armature current waveform — one phase significantly lower than the others — indicates a missing or weak firing pulse on one thyristor channel.

This can result from a faulty pulse output circuit on the new PIB, a damaged gate cable connection at the PIB's terminal, or a failed thyristor module that does not respond to its gate pulse. Confirm that all gate cable terminals at the new PIB are firmly seated before suspecting a board defect.

Q3: Is the C98043-A7002-L1 compatible with all 6RA70 drives, or only specific power ratings?

The PIB board serves the control electronics section of the 6RA70, which is the same architecture regardless of the drive's armature power rating.

The PIB is not rated by armature current — the armature current rating is determined by the thyristor modules in the power section, not by the PIB. 

The same C98043-A7002-L1 serves 6RA70 drives from the smallest to the largest armature current ratings, provided the L1 variant is confirmed correct for the specific drive's hardware generation.

Q4: The old C98043-A7002-L1 board had visible scorch marks near one of the firing pulse output areas. Should the thyristor modules in the power section also be checked before installing the replacement board?

Absolutely. Scorch marks on the PIB firing pulse output area typically indicate that a thyristor gate drive fault created abnormal current in the gate circuit — this can originate from a failed thyristor (short gate-cathode path) rather than from the PIB itself.

Before installing the replacement board, test each thyristor module for gate-cathode resistance and check for short-circuit conditions across the thyristor's main terminals. Installing a new PIB on a drive with a failed thyristor that caused the original damage will re-damage the new board.

Q5: The drive is a four-quadrant 6RA70 (reversing). Does the C98043-A7002-L1 handle both the positive and negative bridges, or is a second PIB required?

The single C98043-A7002-L1 handles both the positive and negative thyristor bridges in a four-quadrant 6RA70 drive.

The PIB contains the bridge changeover logic — it manages the suppression of the active bridge, monitors current extinction, and enables the opposing bridge at the correct moment. 

The two bridge circuits are served from a single PIB board. A second PIB is not required for four-quadrant operation.