By Dovydas Kersys · Chapter 22 of 58 in Machine Commissioning.
Before you begin: Follow the machine documentation, risk assessment, site procedures and lockout/tagout requirements. Commissioning can expose personnel to electrical energy, stored pressure and unexpected motion. Never defeat a safety function merely to make a test easier. Examples and diagrams are generic and must be checked against the actual machine.
Variable-frequency drives combine power electronics, protection, control logic and machine interface signals. Commission them in layers: power, motor data, control source, safety, direction, speed reference and process load.
Treat the VFD as its own control system with commands, feedback and safety interfaces.
Why this matters during commissioning
Changing many drive parameters at once can make startup faster only when everything is right. When something is wrong, it makes diagnosis much slower.
Commissioning procedure
- Verify input power and motor cable connections.
- Enter motor nameplate values and required control mode.
- Confirm start/stop command source and speed-reference source.
- Verify STO/safety state and drive-ready feedback.
- Jog at low speed and confirm direction.
- Check current, acceleration/deceleration, minimum/maximum speed and fault limits.
- Save or export final parameters.
Common failure patterns
- Drive is in local keypad control while PLC expects remote control.
- Wrong motor base frequency or current.
- Minimum speed parameter prevents expected slow jog.
- Deceleration too short and causes DC-bus overvoltage.
Evidence to record
- Drive model/firmware
- Motor data
- Control mode/source
- Key parameter values
- Initial current/speed
- Final backup
FIELD RULE: Always record the final parameter set. A replacement drive is only easy when the known-good settings exist.
Appendix D. Drive Parameter Record
Print or duplicate this page as needed. Record actual measurements and references rather than relying only on check marks.
| Parameter | Description | Initial | Final | Reason / note | Verified by |
|---|---|---|---|---|---|
Continue the series
- Previous chapter: Motor Pre-Start Checks: Commissioning Guide
- Next chapter: Motor Direction and Phase Rotation: Commissioning Guide
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Adapted from Machine Commissioning for Maintenance and Automation Technicians, by Dovydas Kersys. © 2026 Dovydas Kersys. Featured cover image is an AI-generated editorial illustration.