Input line reactors

[Brian123]

When installing more than one VFD in a machine, can you have one input line reactor that feeds the VFDs or should each VFD have its own reactor? The VFDs that I am looking at installing are fairly small. I will have one 7.5 HP drive, one 5 HP drive, one 2 HP drive and two 1 HP drives.

Brian

 

[jrwb4gbm]

I have put reactors more often on the outputs due to longer motor lead runs on a multiple drives setup. This was to solve a problem in that thay were stopping for no apparent reason. The only time I needed to put reactors on the input of the drives was to fix a problem (interference) with a PLC and HMI controlling the drives.

 

[KP_EENG]

Input side line reactors on VFDs primarily limit voltage and current spikes to the VFD and reduce the amount of harmonic content reflected back to the line voltage. As long as the input line reactor is properly sized, I don't see a reason why you could not do this, but I would check with the drive manufacturer just to be sure.

Regards

 

[DickDV]

You can do this and it is commonly done. Add up the total current, determine how much reactance you need (1%, 3%, 5%) and you've got it.

Just one caution: Remember that reactors drop voltage so, if you are already in a low voltage environment, reactors might not be the right choice. If, on the other hand, you can afford to loose 1,3, or 5% of the input voltage, then you'll be ok.

 

[Brian123]

Thanks all.

Brian