Heat from a VFD

[SeattleLuke]

Does anyone have a good method for calculating the heat generated by a VFD?

 

[walkes]

No calculations, just getting the information from the manufacturer or their representative.

 

[marcoh]

As an initial estimate assume a VSD is 97% efficient, or 3% is lost as heat. If the amount of heat is an issue confirm with the manufacturer.

 

[ozmosis]

I would agree with marcoh, 3% is typical. All manufacturers will stipulate this somewhere in their documentations.
Additionally, if you are fitting AC line reactors to the input of the drive or other options that are handling the drive/motor current, then these too will generate heat.
If it is to be used to calculate an enclosure size, there are formula to do this.