Siemens A5E00444764 Rectifier Board – MM4 55–90 kW Spare Part

What Is the Siemens A5E00444764 Rectifier Board?

The Siemens A5E00444764 rectifier board is a critical power-stage component designed specifically for MICROMASTER 4 (MM4) drives operating in the 55–90 kW range. Identified by the OEM sub-code MM4F-BGR.RCC6 400V COATED, this board functions at the input rectification stage of the drive, converting incoming 3-phase AC power into the DC-link voltage required by the inverter.

Supplied as an authorized service repair part, it allows maintenance teams and industrial buyers to restore drive functionality efficiently without the need to replace the entire MICROMASTER 4 unit. The board features a protective coating for enhanced resistance against harsh industrial environments.

Technical Specifications & Compatibility

Please review the technical data carefully to ensure compatibility with your specific drive configuration.

Important Compatibility Note: The MM4 series utilizes distinct boards for different power stages. The A5E00444764 is strictly the rectifier board. It should not be confused with the inverter/IGBT trigger board or the surge absorption board. These components are not interchangeable.

When to Replace the A5E00444764 Rectifier Board

Because the MM4 series is now classified as obsolete by Siemens, sourcing a tested replacement is often the fastest path to getting a 55–90 kW drive back online. You may need to replace this rectifier board if the drive exhibits the following symptoms:

• DC Bus Voltage Abnormalities: Repeated under-voltage faults (such as F0003) after confirming the input supply is stable.
• Input Rectifier Faults: Measured three-phase input currents are significantly unbalanced without any loose cable connections.
• Visual Damage: Visible burn marks, cracks, or component failure on the original board.
• Startup Failures: The drive is unable to power up or trips immediately during operation.

Condition & Quality Inspection

To ensure reliability for your critical repairs, each unit is carefully inspected before dispatch. Our inspection process includes:

• Verifying the board code and revision matches MM4F-BGR.RCC6.
• Inspecting the integrity of the 400V coating.
• Visual inspection of the rectifier section and terminal points.
• Photographic records are available upon request prior to shipping.

Ordering & Model Verification

To prevent costly mis-purchases, we strongly recommend verifying the drive model, rated power, and original board markings before ordering.

How to verify: Please check your drive nameplate for the full order number (MLFB) and inspect the label on the existing board. If you are uncertain about compatibility, simply contact us with a photo of your drive nameplate and the original board label. Our technical team will review it to confirm if the A5E00444764 is the correct fit for your equipment.

FAQ

Is A5E00444764 compatible with all MM4 55–90 kW drives?

No. While it is designed for the 55–90 kW range, compatibility depends on the specific frame size (F/Fx) and drive model (e.g., MM430 vs. MM440). Nameplate verification is required.

What is the difference between A5E00444764 and A5E00444765?

The A5E00444764 is the rectifier board. The A5E00444765 is typically the surge absorption board. They perform different functions in the drive’s power stage and cannot be used interchangeably.

Is this part new, refurbished, or obsolete?

Siemens has discontinued this part (Obsolete status). We supply original pulled units in verified condition—they are not repaired or refurbished, ensuring you receive authentic OEM hardware.

What is the typical lead time?

Lead time depends on current stock. Please contact us with your required quantity for the most accurate dispatch and shipping timeline.