Is RC dv/dt snubber same as dv/dt filter on VFD output? 3

[edison123]

I am looking at the below schematic of a 3 ph VFD, which has an input reactor (with an input surge suppressor connected in parallel across the input reactor), VFD, an output reactor with a RC dv/dt snubber connected in parallel across the output reactor.

Is this RC dv/dt snubber same as dv/dt filter on VFD output?

Sorry for the picture quality. Unable to upload the pdf.

Muthu

http://www.edison.co.in

 

[Gr8blu]

A "layman's" approach to defining passive protection can be found at:

https://dvdtfilter.com/passive-filter-topologies-for-motor-protection/

Converting energy to motion for more than half a century

 

[edison123]

Thanks, gr8blu.

So, inline inductive filters (LR, LC, LRC) are better than across the line RC filters for reducing dv/dt as well as voltage spikes?

Muthu

http://www.edison.co.in

 

[LionelHutz]

I can't see your dwg clear enough to make out anything useful on it.

Inductors are the only components inline. A resistor or series resistor-capacitor might be put in parallel with the inductor but you won't find any combination of those components inline without the inductor being the main path.

C or R-C networks are put from phase to phase which will force a transient on one phase into the other 2, which just lowers the overall peak. Better yet is phase to ground to shunt the transients to ground.

 

[edison123]

Lionel

Pdf is attached. Is the output reactor with the RC snubber good enough to reduce peak V and dv/dt significantly?

Muthu
www.edison.co.in

 

[jraef]

The combination of the output reactor plus the RC snubber is what comprises a DV/DT filter assembly. I suppose one could buy and install the components separately, but just buying a manufactured DV/DT filter would be much simpler.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[edison123]

Thanks, Jeff.

Muthu

http://www.edison.co.in