ABB NAMU-01C 64702475D | Auxiliary Measuring Unit for ACS800 Wind Turbine Converters

Description

Key Technical Specifications

ABB’s ACS800-67LC hardware manual explicitly identifies NAMU-01C as an Auxiliary Measuring Unit and states that it is connected to CH2 of the RDCO module. ABB’s upgrade documentation also provides specific jumper settings for NAMU-01C installation.

Do not rely on generic online specifications for this part. Several secondary descriptions assign NAMU-01C unrelated Modbus, PLC, temperature, or general-purpose analog-I/O specifications. Those claims are not supported by the ABB ACS800-67LC documentation I could verify.

Product Introduction

ABB NAMU-01C 64702475D

The ABB NAMU-01C 64702475D is an auxiliary measuring unit used in ABB wind turbine converter hardware, particularly the ACS800-67LC architecture. Its documented role is to interface auxiliary measurement signals with the converter control system; ABB specifically shows the unit connected to CH2 of an RDCO module.

This is a converter-specific service component, not a general-purpose PLC analog-input card. That distinction matters during procurement. The surrounding RDCO configuration, wiring, jumper positions, and cabinet design determine whether a is actually interchangeable with the installed unit.

NAMU-01C

Application Scenarios & Field Pitfalls

Engineering Pain Point

A wind-turbine converter can continue to show a confusing mix of measurement and control faults when an auxiliary measurement interface is compromised. The mistake I see most often with legacy converter hardware is replacing the module based only on the label, then discovering that the jumper configuration or associated RDCO channel does not match the original installation.

Typical Applications

• Wind Power — Auxiliary measurement and control-interface functions in ABB ACS800-67LC wind turbine converters.
• Wind Turbine Converter Cabinets — Signal measurement associated with converter control and monitoring hardware.
• Power Conversion Systems — Auxiliary measurement paths surrounding the ABB ACS800 converter control architecture.
• Converter Retrofit Projects — Replacement of failed units during maintenance of legacy wind turbine equipment.

Technical Pitfalls to Avoid

1. Verify the RDCO connection.
   ABB’s hardware manual specifically states that the is connected to CH2 of the RDCO module. Do not assume that any available RDCO channel is equivalent.
2. Record jumper positions before removal.
   This is important. ABB’s upgrade documentation specifies jumper arrangements for installation, including X8, X11, X12, X13, X14, X15, and X21. A replacement with incorrect jumper settings can produce misleading measurement or control behavior.
3. Do not confuse with NDBU-95C.
   ABB’s installation documentation discusses both units during NAMU/NDBU plate replacement. They serve different functions and should not be treated as interchangeable.
4. Check the complete cabinet wiring.
   is part of a larger converter measurement architecture. Check terminal wiring, auxiliary supply, RDCO connection, and associated measurement circuits before condemning the module.
5. Do not infer the function from generic marketplace descriptions.
   Some secondary listings describe as a six-channel analog module, temperature controller, or general Modbus interface. Those descriptions are not consistent with ABB’s -67LC hardware documentation. The OEM documentation should take precedence.
6. Check the mounting arrangement.
   ABB’s upgrade instructions describe replacing on the installation plate DIN rail. Confirm the mechanical arrangement before attempting a direct substitution.
7. Inspect the auxiliary supply before replacement.
   If the NAMU appears completely inactive, prove the supply and cabinet wiring first. Replacing the module without checking the upstream supply can result in a second unexplained failure.
8. Keep the original wiring record.
   These are legacy converter cabinets. Drawings may have been modified over years of service. Photograph and document terminal and jumper positions before removing the old unit.
9. Do not energize immediately after changing jumpers.
   Verify every jumper and connection against the applicable ABB hardware or retrofit documentation before restoring converter power.
10. Treat the module as part of the converter control system.
    A NAMU replacement should be followed by the appropriate converter diagnostics and measurement verification, not simply a visual power-on check.

Related Products

• ABB RDCO Module — The communication/control interface with which is documented to connect. ABB specifically identifies CH2 of the RDCO module as the connection po the architecture.
• ABB NDBU-95C — Related auxiliary/converter hardware appearing in ABB’s NAMU/NDBU mounting-plate replacement procedure. It is a different unit and should not be substituted for without checking the converter design.
• — Wind turbine converter platform explicitly documented with . This is the most relevant system reference when checking compatibility.
• — Broader wind turbine converter family associated with NAMU/NDBU auxiliary measurement hardware. Exact hardware configuration varies by converter revision.
• ABB ACBU-A2 — Converter control hardware shown in ABB’s upgrade documentation alongside the inverter and measurement wiring. It is part of the broader converter control architecture rather than a direct replacement for .
• ABB NIOC-01 — I/O/control hardware appearing in the -67 wiring documentation. It handles other converter control functions and is complementary to the NAMU measurement path.
• ABB INU — Inverter unit referen the power-stage wiring. It is a power-conversion component, whereas serves the auxiliary measurement/interface layer.
• ABB -67 Upgrade Kit Hardware — Relevant when maintaining older wind turbine converters and replacing obsolete NAMU/NDBU assemblies. ABB’s retrofit documentation provides the installation procedure and jumper information.