VFD Input VS Output Current

[blues]

I would like to know why the input current of a VFD would be differnt than the output from the VFD to say a 200hp, 3ph, 480v motor load. I can only assume it may have something to do with the harmonic content of the conductors feeding the VFD as apposed to the conductors leaving the VFD once the line reactor has filtered out the harmonics to the pump. Or am I way out in left-field on this one.

Thanks
Dan Craven

 

[sgunsel]

Efficiency of the inverter unit. Every conversion consumes energy, and you are converting from ac to dc and back to ac. Other limitations may occur due to ratings of specific components in the inverter circuitry.

 

[Besoeker]

Efficiency of the inverter unit. Every conversion consumes energy, and you are converting from ac to dc and back to ac. Other limitations may occur due to ratings of specific components in the inverter circuitry.

Power factor is the major cause of the difference.
Input power factor is generally much higher than output power factor as has been discussed in another thread on this topic.

 

[charlie b]

Duplicate. Please continue the discussion here:
http://forums.mikeholt.com/showthread.php?t=147002