Diagnostic workflow

Rectifier-Section Failure Repair-Versus-Replace Workflow

Entry symptom: A legacy integrated module appears to have rectifier/input-side damage while the inverter section may not show the same evidence.

Safety controls before proceeding
  • Treat this as specialist bench work; do not convert the workflow into field modification instructions.
  • Verify isolation, surge and DC-link discharge before any inspection.
  • Manufacturer documentation and site engineering rules remain controlling.

Investigation sequence

1

Identify module topology

Record whether the rectifier and inverter are combined in one PIM/IPM package and capture exact markings before making an economic decision.

2

Test sections separately

Compare input diode/rectifier measurements with output transistor measurements; do not infer the whole package condition from one terminal group.

3

Find why the rectifier failed

Check surge path, varistors, precharge, input contactor, fuses and DC capacitors before any replacement strategy.

4

Assess remaining inverter trust

If the inverter section has ambiguous leakage, heat history or previous output faults, a partial strategy may not be responsible.

5

Choose the commercial route

Document whether the result supports full module replacement, specialist repair, drive replacement or modernization.

Stop conditions

  • Output section has leakage or short evidence
  • DC link capacitors are suspect
  • Line-side surge cause is unresolved
  • Exact module identity is uncertain

Linked records