Original Siemens Cib Communication Component 6SL3351-6GH31-8AB3 6SL33516GH318AB3 6SL3 351-6GH31-8AB3

Siemens 6SL3351-6GH31-8AB3 | SINAMICS G Replacement Control Interface Board — 660–690V, 175A, 50/60Hz

Part Number: 6SL3351-6GH31-8AB3

Manufacturer: Siemens AG (Germany)

Product Type: Replacement Control Interface Board (Spare Part)

Product Family: SINAMICS G (6SL3351 spare part series)

Voltage Rating: 660–690V 3AC

Current Rating: 175A

Frequency: 50/60 Hz

Compatible Unit: SINAMICS G Power Module, 660–690V, 175A

Enclosure: IP00 (chassis board)

Country of Origin: Germany

Overview

The 6SL3351-6GH31-8AB3 is a Siemens SINAMICS G replacement control interface board — a spare part manufactured to restore failed control boards in SINAMICS G-series drive Power Modules operating on 660–690V three-phase AC supplies at a rated output current of 175A.

This board is the control electronics layer inside the drive's Power Module: it processes commands from the drive's Control Unit, generates the IGBT gate drive signals, monitors feedback, and manages all the protective functions that keep the drive operating safely.

The SINAMICS G platform covers a wide range of industrial variable-speed drive applications — pumps, fans, compressors, conveyors, and general-purpose AC motor speed control in energy-intensive industries.

At the 660–690V level, the platform targets higher-voltage industrial networks common across Europe, the Middle East, and large-scale industrial facilities running from medium-voltage distribution systems step-down to 660V or 690V.

The 175A current rating at this voltage corresponds to motor sizes in the 160–200kW range, placing this board in the heavy-duty section of the SINAMICS G portfolio.

The 6SL3351-6GH31-8AB3 is the latest revision (suffix -8AB3) of the 175A board in the 6SL3351-6GH31-8 family. Revision AB3 supersedes earlier AB0, AB1, and AB2 versions of the same board.

The revisions maintain functional compatibility while incorporating component updates, reliability improvements, and compliance with updated electromagnetic compatibility requirements.

When sourcing a replacement, the latest revision is always the appropriate choice unless a specific older revision is required for compatibility with an early firmware release.

Key Specifications

SINAMICS G Control Interface Board — Functional Role

In the SINAMICS G drive architecture, the Power Module is the physical drive unit containing the power electronics: the DC bus capacitors, the IGBT switching transistors, the current sensing resistors, and the associated gate drive circuits.

The control interface board occupies the control layer within this assembly. 

It receives switching commands from the CU (Control Unit) and translates them into precise gate drive pulses for the Power Module's IGBTs. It simultaneously reads back the actual motor phase currents and reports them to the CU's control loop, enabling the vector or scalar motor control algorithm to regulate speed or torque accurately.

In addition to these core switching and sensing functions, the 6SL3351-6GH31-8AB3 implements the protective monitoring functions within the Power Module.

It monitors the DC bus voltage, the IGBT junction temperatures (via NTC sensors on the heatsink), and the motor phase currents.

When any parameter exceeds its safe limit, the board immediately inhibits the IGBT gate signals, stopping the motor output.

This protection response is implemented in hardware on the control board — it does not wait for the CU's software to respond, ensuring that a fault clears the drive output within microseconds.

The board also manages the drive's interface to the external brake chopper circuit, where fitted, and the IGBT desaturation detection circuits that protect against transistor short-circuit conditions.

SINAMICS G Drive Applications — 660–690V Range

At 660–690V, the SINAMICS G drives serve industrial applications where the local power distribution operates at these higher network voltages.

Large pump and fan applications, compressor drives, materials handling conveyors, and industrial processing equipment — including steel mills, cement plants, mining installations, and petrochemical facilities — all make use of drives in this voltage range.

At 175A output current, the 6SL3351-6GH31-8AB3 serves motors in the 160–200kW power range on 690V networks.

These motor sizes handle large pump impellers, centrifugal compressors, mine ventilation fans, and heavy conveyor drives.

The demands on the drive's control board are correspondingly stringent — gate drive accuracy, current feedback fidelity, and protection response speed all affect the performance and reliability of high-power industrial equipment.

Installation and Replacement

The 6SL3351-6GH31-8AB3 is installed inside the SINAMICS G Power Module with the drive fully de-energised and the DC bus discharged.

The DC bus holds significant energy after mains power is removed — a minimum waiting period of 5 minutes after power-off is required before opening the drive, and the actual DC bus voltage must be confirmed below 50V before commencing work.

The replacement procedure involves removing the faulty board, installing the new board, reconnecting all internal connectors, and recommissioning the drive.

After board replacement, the CU re-detects the Power Module through its internal communication link and may require a commissioning confirmation step before normal operation resumes. 

No parameter changes are typically required when replacing the control interface board with the identical revision, but if the revision has changed, verify that the installed CU firmware supports the new board revision.

FAQ

Q1: The SINAMICS G drive shows fault F30001 (overcurrent) at no load with no motor connected. The DC bus voltage is correct. Is the 6SL3351-6GH31-8AB3 at fault?

F30001 at no load with no motor connected and correct DC bus voltage points to a current sensing fault on the control board.

The board's current feedback circuits are reporting a phase current where none should flow. Check the current sensing connections on the board first. 

If connections are secure and fault persists, the current sensing section of the 6SL3351-6GH31-8AB3 has failed.

Q2: After replacing the 6SL3351-6GH31-8AB3, the drive starts but trips on F30035 (temperature) within minutes at moderate load. What should be investigated?

F30035 after a control board replacement suggests either the NTC temperature sensor connection was not properly re-established during installation, or the NTC sensor on the heatsink has failed. The temperature sensing circuit on the 6SL3351-6GH31-8AB3 monitors the heatsink NTC sensors.

Verify all NTC sensor cable connections are firmly seated on the new board.

If connections are confirmed good and the temperature reading on the CU's diagnostic screen appears incorrect (too high or too low), the NTC sensor itself requires inspection.

Q3: The 6SL3351-6GH31-8AB3 revision AB3 is the replacement, but the original was AB1. Is there any compatibility concern?

AB3 supersedes AB1 and is fully compatible in the same application. Siemens maintains backward compatibility across revision levels for the same base part number.

The later revision incorporates component updates and may reflect improved electromagnetic compatibility measures or modified component sourcing, but the functional specification and physical dimensions are unchanged.

No additional commissioning steps are required when upgrading the revision.

Q4: The SINAMICS G drive trips on F30022 (IGBT overcurrent / transistor fault) under heavy load. The motor and cables are confirmed healthy. Does this indicate a control board fault?

F30022 under confirmed-healthy motor and cable conditions may reflect a gate drive fault on the 6SL3351-6GH31-8AB3 — a condition where one or more IGBT gate drive outputs are providing insufficient gate voltage, causing a transistor to switch incompletely and saturate.

However, F30022 can also be caused by a failed IGBT in the Power Module's power section. 

Fault isolation requires assessing whether the trip occurs on a specific phase (suggesting a localised fault) or all phases simultaneously (more consistent with a control board fault). Specialist equipment is required to confirm.

Q5: This drive operates in a humid coastal environment. Should any precautions be taken when installing the 6SL3351-6GH31-8AB3 in this setting?

High humidity and salt-laden coastal air accelerate corrosion on circuit board contact surfaces and connector pins. Siemens recommends conformal coating for circuit boards in such environments — the standard 6SL3351-6GH31-8AB3 board is not pre-coated.

When installing in a coastal environment, ensure the drive cabinet provides the specified IP protection rating for its enclosure, and verify that the drive's cooling air intake does not draw in outdoor air.

Contact Siemens regarding specifically treated board variants if the installation is particularly exposed.