A reliable VFD installation needs a model-specific design for the supply, motor circuit, grounding, controls and cooling. Use this checklist to prepare the engineering review; terminal assignments and protective-device ratings must come from the supplied manual and approved drawings.
Begin with the approved equipment configuration
Identify the complete drive model, input supply, motor data and cabinet scope. Confirm whether the system uses a basic rectifier, AFE, shared DC bus or resistor braking. These arrangements have different supporting circuits and should not share an assumed generic wiring diagram.
Installation and electrical testing should be performed by qualified personnel using the required isolation and verification procedures. Stored DC-link energy remains a consideration after the supply is disconnected; follow the equipment’s specified procedure rather than relying on a dark display.
Review these interfaces before installation
| Area | Questions to resolve |
|---|---|
| Incoming supply | Voltage, grounding system, fault level, isolation and coordinated protective devices. |
| Motor circuit | Cable type and length, motor insulation, shielding and any output filter requirement. |
| Grounding and EMC | Protective earth, bonding, shield termination and cable separation according to the manual. |
| Controls and feedback | I/O voltage, PLC protocol, encoder type, connectors and signal routing. |
| Braking | Chopper/resistor selection or regenerative path, thermal protection and machine brake sequence. |
| Cooling | Air clearances or coolant conditions, losses, monitoring and maintenance access. |
When should output reactors or filters be considered?
Review the motor cable length and type, switching conditions, motor insulation and installation requirements. An output reactor, dV/dt filter and sine-wave filter serve different purposes and are not interchangeable accessories. The choice must also suit the drive’s operating frequency and the required motor-control performance.
For a remote pump motor or a retrofit using an older motor, provide the actual cable and nameplate information. Do not select a filter from distance alone or assume that any output filter is compatible with a high-speed motor.
Keep control wiring tied to the system design
Confirm communication option cards and the PLC data mapping before commissioning. Encoder signal type and supply must match the feedback interface. Separate ordinary operating commands from safety-related functions; a fieldbus stop command is not automatically a certified safety function.
Prepare for commissioning
- Review the installed equipment against the approved drawings and model manuals.
- Record the motor data, required operating limits and parameter baseline.
- Agree controlled tests for direction, references, interlocks and feedback.
- Verify the cooling and braking behaviour under the agreed operating conditions.
- Keep the final parameter record and document any changes made during commissioning.
INOMAX application support
For MAX-series or ACS drive projects, send the drive model, motor data, cable details, supply information and control-system requirements to INOMAX. For ACS880 engineered systems, include the selected rectifier, feedback and cooling arrangement. The download center and project-specific documentation should be used for the current model instructions.
Frequently asked questions
Can I copy the terminal wiring from another drive brand?
No. Compare the actual terminal functions, electrical ratings, logic, feedback and safety interfaces using both manufacturers’ documentation.
Can I test motor insulation while the motor remains connected to the drive?
Follow the specific isolation and testing procedure in the manual. Insulation tests must not be applied to connected drive electronics in a way the manufacturer prohibits.