What capacity of inverter (VFD) is required to run 5 KW load ? What's the formula ?

[phatcreators]

What capacity of inverter (VFD) is required to run 5 KW load ?
What's the formula for selecting an inverter for a particular load ?

thanxXx

 

[kak111]

Commonly the inverter is selected in accordance with the the motor
because one of the VDF duties is protect the motor.
For that is non any special calculation formula.
Normally start selection with supply voltage , motor power and motor current
check application type, motor type, rpm-range, braking ..........


Look this ............
Drive Selection Guide Flowchart page 42....
**broken link removed**

 

[atripathi]

by VFD: Do you mean variable frequency drive?

 

[kak111]

Do you mean variable frequency drive?

Sorry about my clumsy fingers should be VFD.

 

[FvM]

Most manufacturers are offering a VFD inverter portfolio apposite to the industry standard motor power classes, e.g. 5.5 kW. If you look at the detailed technical data, you'll notice, that a 5.5 kW inverter is prepared for expectable currents of this motor size, including a certain temporary overcurrent capability. For extreme conditions, e.g. very heavy load, particularly high breakaway torque that happens with some kind of machinery, you would want to choose an inverter power overhead, up to doubled nominal power.

Partially contradicting a statement of kak111: It isn't a problem to use an oversized inverter, because all motor limit conditions can be precisely programmed in the inverter setup, that usually starts with automatic identify of electrical motor parameters. If you have to deal with a heavy load condition as described above, it can be tricky to find a safe setup. Additional precautions like windings temperature monitoring are most likely required in such situations.