IndustrialDriveDataDrive Board & Diagnostic Database
Control board / power-interface service evidence

Siemens SIMOREG 6RA70 CUD1 / Power Interface Evidence Record

Collects the evidence needed before CUD1, power-interface, thyristor firing or donor-converter decisions on SIMOREG 6RA70 field, armature-current and no-display cases.

Board evidence record8 min read

Scope of this technical record

Evidence record for CUD1, PMU, power-interface, field feedback and armature firing paths before repair, donor board or modernization decisions.

Safety boundary

Do not remove or replace board assemblies without documenting connector positions, board labels and the fault route that led to the board boundary.

What to collect

Collect type code, CUD1 label, PMU behavior, power-interface label, field and armature connector photos, fault value, operating state, field proof, armature fuse evidence and details of previous board or bridge replacements.

How this record is used

The record helps classify the case as field circuit, armature/firing, electronics supply, CUD1, power interface, donor-board risk or modernization. It is meant to prevent a replacement board from being installed into an unresolved external fault.

Field record checklist

  • Type code
  • CUD1 label
  • PMU behavior
  • Power-interface label
  • Field proof
  • Armature/fuse proof
  • Connector positions
  • Previous repair history

Technical basis and reference documents

This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.

FAQ for 6RA70 DC MASTER and SIMOREG CM fault diagnosticsSiemens Industry Support

Used to verify that 6RA70 fault work should preserve the fault value and separate CUD1 / power-interface evidence from field and armature circuit evidence.

SIMOREG 6RA70 Series operating instructions and system overviewSiemens

Used to confirm the 6RA70 architecture as a three-phase AC supplied DC converter for armature and field circuits, with hazardous service boundaries around power and control electronics.

Linked circuit records

Circuit
Siemens SIMOREG 6RA70 Field Supply and Feedback Path

Routes F005 cases from the selected motor field and field supply through fuses, F+ / F- wiring, field-current feedback and CUD1 interpretation before a control or interface board is blamed.

Open →Circuit
Siemens SIMOREG 6RA70 Armature Thyristor Firing and Current Path

Maps F030 and current build-up failures through armature fuse, contactor, motor armature circuit, thyristor bridge, firing path, current feedback and field proof before power-interface decisions.

Open →Circuit
Siemens SIMOREG 6RA70 CUD1 Electronics Supply and PMU Display Path

Separates a no-display or reset-loop 6RA70 case into cabinet supply, electronics supply, CUD1 boot state, PMU/interface path, downstream loading and power-interface loading evidence.

Open →
Evidence intake

Turn this record into a qualified service request

A repair decision is much more reliable when the request includes the exact identity of the drive, the first fault evidence and the machine condition when the symptom appeared.

  • Complete drive type code / MLFB or nameplate model
  • Fault code, fault value and first event before reset
  • When the event appears: power-up, enable, ramp, run, decel or stop
  • Motor/cable connected or isolated during the symptom
  • Visible board, option-card, module and connector identifiers
  • Previous repair history, replacement parts and repeat-failure pattern
Prepare request →