Procedure for commissioning a VFD

The process of

• Checking,
• Inspecting,
• Testing, and
• Configuring the equipment 

will satisfy the technical and functional requirements of the consumer is known as commissioning of a variable-frequency drive. The machinery has been set up for safe operation

The process for commissioning a VFD is described in this post.

Why is VFD commissioning important?

The following considerations are given for commissioning variable-frequency drives:

• To confirm that all safety requirements (IEC 60364) have been achieved by the apparatus and any associated field devices.
• Must make sure that the right cables are chosen, installed, and terminated.
• To confirm that the motor and variable frequency drive are correctly grounded.
• To confirm that the equipment is operational and complies with any contractual terms or requests from the consumer.

Instruments needed for commissioning a VFD

The commissioning engineer needs to examine the application and the consumer’s requirements before commencing the commissioning procedure. Before the commissioning procedure starts, make sure the instruments are organized.

• Wiring layout.
• Clamp-meter.
• Handy Calibrator.
• Full load current, rated voltage, and rated RPM are listed on the motor nameplate.
• Details of the field instruments (such as the pulse encoder, flow transmitter, pressure transmitter, and pressure switch).
• VFD user handbook.

VFD commissioning process

The VFD is prepared for commissioning once the pre-commissioning inspections are finished and every system is determined to be in working order. The following stages are involved in commissioning the drive.

1). Input supply voltage should be checked

Check the power voltage at the supply end of the CB – circuit breaker terminals before turning on the VSD. Turn on the circuit breaker if the source voltage is within the VFD’s rated source voltage range. At the drive’s DC bus terminals, check the voltage on the DC bus.  Make that the cooling fan is operating properly as well.

2). Set every other command and correspondence setting

The majority of variable frequency drives on sale come pre-set with application-based specifications. However, regardless of the application, the following parameters must be set.

3). Minimum output frequency

The VFD’s output frequency cannot be changed beneath the highest output frequency; the minimum output (O/P) frequency is the bottom limit for frequency.

4). Maximum output frequency

The more extreme limit for frequency is the maximum output frequency, which means that the VFD’s output frequency cannot be changed above that level.

5). Maximum output current

The highest permitted output current is known as the maximum output current. If the output current of a VFD exceeds the preset limit while it is operating normally, the drive can trip on an over-current fault. During the initial phase, the current may go over the top limit.

Post-VFD Commissioning

Make a thorough report of the work done once the variable frequency drive has been successfully installed. Keep track of all test settings, current measurements, and test frequencies when doing tests both with and without load.