# Yaskawa VFD's and 230VAC 3 phase.



## frenchelectrican (Mar 15, 2007)

tates1882 said:


> Hey all,
> 
> I'm looking for some points of clarifications on Yaskawa VFd's, I spoke with tech support but he didn't seem over sure of his answer. Will the Yaskawa v1000 work with a high leg 230 volt system? According to tech support " it will work fine the MOV's are referenced from phase to phase not phase to ground."
> 
> Thought?


It hard to say if it is safe to work on high leg due I have not work on that version yet but the larger one ya I did work on it. 

however .,,, some can work just fine on high leg without issues but most VSD MOV's typically in set in wye format but it should have a instuction to remove the jumper if going to run in high leg or corner grounded system.


----------



## JRaef (Mar 23, 2009)

That tech person is *wrong*. If you make a VFD that needs to have "CE" labeling, as is required basically _*everywhere*_ in the world EXCEPT North America, you are _*required*_ to have everything inside of the VFD referenced to ground. There is _*zero chance*_ that Yaskawa drives are not CE compliant...

One issue I've seen with many VFDs designed outside of North America and shipped here for sale, is a lack of understanding of the fact that WE have the potential to connect to Delta power systems. That exists nowhere else outside of NA. Drives designed by NA companies, such as A-B, take that into consideration and provide simple jumpers that can be pulled to remove the ground reference point. In addition most of the European drive manufacturing companies, like Siemens, Schneider and ABB, have eventually figured this out and provide, at the very least, instructions on how to modify their drives to accommodate Delta supplies by removing that ground reference, although on some (like Siemens where I used to work), you have to literally disassemble the front-end of the VFD to get access to the connection, clip and tape off a wire, then reassemble it. Oh and by the way, this voids the UL listing on all drives (including the A-B ones with the jumpers) and by removing that ground reference, all you do is help prevent the MOVs and Common Mode Noise caps from blowing up and making a mess. You ALSO remove the protection from Line-Ground spikes and surges they provided... 

I've also found that most Asian drive mfrs, despite having been marketing in NA for 2 decades now, still don't get it. Yaskawa, as big as they are, is included. Here is the sum total of what they say, which is indirect, and only IF you understand the terminologies.


> The drive is designed to be used in T-N (grounded neutral point) networks. If installing the drive in other types of grounded systems, contact your dealer or Yaskawa for instructions.


T-N means a Wye power system, so they are telling you that it is ONLY designed to be connected in a Wye system, but "contact us" if that's not what you have. But then nowhere in their available tech support documents does it actually say what to do and as witnessed here, even their phone tech support people are untrained in this issue. I used to be a Yaskawa official integrator, this issue frustrated the heck out of me and I complained about it a LOT, but it fell on deaf ears. They just don't get it. Back in those days I WAS eventually able to find a single US based Engineer on their staff in L.A. that understood and his solution was: _*install a Delta-Wye drive isolation Transformer ahead of each drive (or group of drives)*_. While this is a solution that I usually recommend because of what you expose the VFD to by removing the ground reference, it is sad that once that one guy at Yaskawa left, nobody there picked up the ball.


----------



## tates1882 (Sep 3, 2010)

JRaef said:


> That tech person is *wrong*. If you make a VFD that needs to have "CE" labeling, as is required basically _*everywhere*_ in the world EXCEPT North America, you are _*required*_ to have everything inside of the VFD referenced to ground. There is _*zero chance*_ that Yaskawa drives are not CE compliant...
> 
> One issue I've seen with many VFDs designed outside of North America and shipped here for sale, is a lack of understanding of the fact that WE have the potential to connect to Delta power systems. That exists nowhere else outside of NA. Drives designed by NA companies, such as A-B, take that into consideration and provide simple jumpers that can be pulled to remove the ground reference point. In addition most of the European drive manufacturing companies, like Siemens, Schneider and ABB, have eventually figured this out and provide, at the very least, instructions on how to modify their drives to accommodate Delta supplies by removing that ground reference, although on some (like Siemens where I used to work), you have to literally disassemble the front-end of the VFD to get access to the connection, clip and tape off a wire, then reassemble it. Oh and by the way, this voids the UL listing on all drives (including the A-B ones with the jumpers) and by removing that ground reference, all you do is help prevent the MOVs and Common Mode Noise caps from blowing up and making a mess. You ALSO remove the protection from Line-Ground spikes and surges they provided...
> 
> ...


Good info thanks. I sell mainly Siemens and was told I that the recommended solution was to double the HP of the vfd and hook it up normally. I asked above cutting the MOV's loose and was told absolutely not, double would provide a dc bus capacity to handle the ripple of transient voltage. I think my course is to find 10hp vfd and feed it single phase, it will control 4-1hp motors that need to turn the almost exactly the same speed. 

thanks Jraef


----------



## JRaef (Mar 23, 2009)

tates1882 said:


> Good info thanks. I sell mainly Siemens and was told I that the recommended solution was to double the HP of the vfd and hook it up normally. I asked above cutting the MOV's loose and was told absolutely not, double would provide a dc bus capacity to handle the ripple of transient voltage. I think my course is to find 10hp vfd and feed it single phase, it will control 4-1hp motors that need to turn the almost exactly the same speed.






tates1882 said:


> thanks Jraef


Yeah, to be clear though, doubling the size has ONLY to do with feeding it with single phase. So if you go that route, make sure to feed it only with the two phases that are referenced to ground (typically A and C).


----------



## tates1882 (Sep 3, 2010)

Well decided to go with the isolation transformer, sort of a pita. Created a SDS and now I have to add a service rated fused disconnect and find a suitable grounding electrode. Not to mention a 14kVA ISO transformer with disconnect and labor added about 5k to the build. Fun explaining this to a group of Eastern European block immigrants after I fielded one system already using yaskawa on a delta system for them. 


Sent from my iPhone using Tapatalk


----------



## micromind (Aug 11, 2007)

tates1882 said:


> Well decided to go with the isolation transformer, sort of a pita. Created a SDS and now I have to add a service rated fused disconnect and find a suitable grounding electrode. Not to mention a 14kVA ISO transformer with disconnect and labor added about 5k to the build. Fun explaining this to a group of Eastern European block immigrants after I fielded one system already using yaskawa on a delta system for them.
> 
> 
> Sent from my iPhone using Tapatalk


And once again, we get blamed for doing something right.........lol.


----------

