Original Siemens Cib Comm. Component 6SL3351-6GH38-1AB3 6SL33516GH381AB3 6SL3 351-6GH38-1AB3

Siemens 6SL3351-6GH38-1AB3 | SINAMICS G Replacement Control Interface Board — 660–690V, 810A, 50/60Hz

Part Number: 6SL3351-6GH38-1AB3

Manufacturer: Siemens AG (Germany)

Product Type: Replacement Control Interface Board (Spare Part)

Product Family: SINAMICS G

Compatible Unit: SINAMICS G Power Module, 660–690V 3AC, 810A 

Overview

The 6SL3351-6GH38-1AB3 is a Siemens SINAMICS G replacement control interface board — the control electronics spare part for a SINAMICS G Power Module operating at 660–690V three-phase AC with an 810A rated output. At this power level, the drive serves motors in the 750–900kW range at 690V, making it one of the highest-current variants in the SINAMICS G 690V product line.

These drives are found in large-scale industrial infrastructure — major water pumping stations, mine ventilation systems, air compression trains, large centrifugal compressors, and steel plant fan arrays.

The board sits at the electronics layer of the Power Module. It handles gate drive signal generation for the IGBT power stage, routes motor phase current feedback to the control system, monitors heatsink temperature, and implements hardware-level protective logic.

Every switching cycle in the drive — occurring thousands of times per second — depends on the correct operation of this board. A fault in the current sensing section produces incorrect torque regulation. 

A gate drive failure on any phase disrupts motor current. Either condition results in a drive trip and an unplanned stoppage.

The AB3 revision is the fourth and current production version of this board, following AB0, AB1, and AB2.

Siemens maintains full backward compatibility across all AB revisions for this board. AB3 can replace any earlier revision without additional configuration steps.

Key Specifications

810A at 690V — The High-End of SINAMICS G

At 810A output current on a 690V supply, the 6SL3351-6GH38-1AB3 operates in conditions that approach the upper current limit of the standard SINAMICS G chassis range.

The IGBTs in the power module at this rating carry very high average currents under full load, and the gate drive requirements are correspondingly demanding. 

Precise turn-on and turn-off timing keeps switching losses within the IGBT's thermal budget. 

Any asymmetry between phases — caused by a partial board failure affecting one gate drive channel — produces unequal current sharing across the three phases and additional IGBT heating.

The DC bus voltage in this power module, rectified from a 690V AC supply, reaches approximately 975V DC. The board's gate drive isolation, component voltage ratings, and transient suppression are all designed for operation at this DC bus level.

Applications at this power level typically run at high duty cycles — large pumps and fans in continuous-duty industrial service rarely stop for more than a few hours at a time.

The cumulative operational hours on the power module are high. 

Combined with the high switching frequency of modern IGBT drives, the thermal stress on the board's components is significant over a service life measured in years.

Fault Recognition — High-Power Drive Symptoms

At 810A, the consequences of a failing control interface board can escalate quickly. A drifted current sensor produces overcurrent trips at loads that the drive should handle comfortably. A degrading gate drive output causes soft switching on one phase — the IGBT turns on and off more slowly than specified, increasing switching losses and heatsink temperature. Over time this thermal stress accumulates.

Specific warning patterns include:

Single-phase overcurrent trips (F30001) that occur at moderate load, clear on reset, and return under similar conditions. This is a current sensing offset fault — the sensor is reporting a phase current higher than the actual value.

Progressive heatsink temperature increase at constant load over several weeks.

This suggests a gate drive timing degradation on one or more phases, increasing IGBT switching losses.

F30017 (heatsink overtemperature) faults that appear before the heatsink is physically hot.

This points to an NTC temperature sensor connector fault — either a loose connector on the board or a failing NTC thermistor.

Installation Safety

The 6SL3351-6GH38-1AB3 is installed inside a drive Power Module connected to 660–690V AC. Before any internal access: isolate the AC supply, wait a minimum of five minutes, and confirm the DC bus voltage is below 50V using a calibrated instrument.

At 690V supply the DC bus retains nearly 975V for a period after isolation — do not abbreviate the discharge waiting time.

All internal work must be performed by qualified electrical personnel with appropriate authorisation and with suitable PPE for the voltage level. Handle the board with ESD precautions at all times.

FAQ

Q1: After installing the 6SL3351-6GH38-1AB3, the drive generates F30001 (overcurrent) on the first run at no-load. Cables and motor windings are confirmed healthy. What is the cause?

F30001 at no-load after board replacement points to an incorrectly seated current feedback connector on the new board.

The connector carries the current sensor signal from the power module to the board's ADC input. 

A loose connector creates a floating input, which the board reads as a current signal — sufficient to trigger an overcurrent alarm.

Power down the drive, discharge the DC bus, reseat all internal connectors firmly, and retry. 

If the fault remains after confirmed connector seating, the issue may be a failed current sensor in the power section rather than the board itself.

Q2: The drive is at 810A / 690V on a large industrial fan. The power module has now failed twice in three years, always with the same IGBT phase failing. Can the control interface board be contributing to this?

Repeated failure of the same phase IGBT is a strong indicator of a degraded gate drive circuit for that phase. A gate drive output that is not producing the specified gate voltage, or is producing it with excessive rise time, causes the IGBT to switch slowly — increasing switching losses and thermal stress in that specific IGBT.

Over months of operation, this thermal stress causes the IGBT to fail.

Replacing the IGBT without also replacing the 6SL3351-6GH38-1AB3 board leaves the degraded gate drive in place, and the new IGBT will likely fail again in a similar timeframe.

Q3: Is the AB3 revision board compatible with a power module that was originally fitted with an AB0 board?

Yes, AB3 directly replaces AB0 with no incompatibility. Siemens designed the AB revision series with full backward compatibility — physical dimensions, connector positions, and functional interface are identical across all revisions.

The AB3 may use updated discrete components relative to AB0, but the board performs the same functions in the same way.

No parameter change or additional commissioning is required.

Q4: The site has five SINAMICS G Power Modules at 810A / 690V in the same installation. Is one spare 6SL3351-6GH38-1AB3 sufficient, or should more be stocked?

For five critical drives on the same site, holding one or two spare boards is prudent. A single spare protects against an isolated board failure.

If there is any concern that multiple boards in the fleet are approaching end-of-life (drives of similar age with similar operational history), holding two spares reduces the risk of a second failure occurring while the first replacement board is being sourced. 

Lead time for this board through the aftermarket supply chain is typically one to two weeks — consider whether that is an acceptable downtime risk given the criticality of the applications.

Q5: The SINAMICS G drive at 810A / 690V produces intermittent phase-current imbalance readings on the drive display, but no fault trips. Is this an early warning of control board failure?

An intermittent current imbalance that appears in the drive's diagnostic display but does not trigger a fault trip is a meaningful warning sign.

The current sensing gain or offset on one channel is drifting — not yet enough to exceed the fault threshold, but enough to show as a measurement discrepancy. 

This will worsen over time. The current offset drift characteristic of an aging current sensing circuit tends to accelerate as the component ages. 

Scheduling a preventive board replacement with the 6SL3351-6GH38-1AB3 during the next planned maintenance window is the appropriate response — before the drift reaches the fault threshold and causes an unplanned shutdown.