vfd suggestions

[Joe Meazle]

I have a 3phase Baldor motor rated at 5hp 13a that I might want to use a VFD for phase conversion. I have seen 3hp single phase input 3 phase output VFD's rated as high as 11a. I have only found one 5hp single in 3 out VFD and it was rated at 17a and $600 :-(
Any one know of anything out ther that might work for me?

Thanks,
Joe

[Rob Russell]

When I was looking for VFDs to drive 7.5 HP motors, I found that 3HP seemed to be the limit reasonably priced single-phase input, 3-phase output VFDs.

If you need one for a 5HP 3-phase motor, they won't be cheap.

Some VFDs will allow you to override the programming and effectively run from single-phase input. It means being able to override "low buss voltage" as being acceptable, but you need to allow for 50% derating on the VFDs output. If you can find a 10HP 3-phase VFD that allows you to override that setting, it could work for you. Note - I have not done this myself, but have read about folks who successfully did it.

[Joe Meazle]

Well, i thought this was more of a Powertool question than a shop question. I would undersand getting moved if I was wanting to install a shop wide 3 phase conversion system but this is for a single tool. Sorry if I made an error.
Joe

[Rob Russell]

Joe, while I don't need to explain why I moved your question, I will as information for others who may ask the same question.

This is not a "power tool" question, it's about converting single-phase electricity to 3-phase electricity. There isn't even any mention in your post about what "tool" the motor is for. That's why I moved it to the Workshops forum.

FYI, we can't keep all posts in the GWW forum. It has too much traffic and posts quickly fall off to the 2nd or 3rd page as it is. That's one reason why we have multiple forums.

This is an "electrical" post and, as such, belongs in the Workhops forum because that's where we put electrical posts.

[Joe Meazle]

Thanks for the clarification.

[Joe Jensen]

It's too bad that this forum is like Siberia, so few visitors :(

[Joe Meazle]

Joe,
Where did you get you VFD for the Jointer? That was good price for the NEMA 4 version.

[Joe Jensen]

Joe, I purchased from this place. The price was great, but they seem to have no technical support what so ever...joe

http://www.power-components.com/price-list.htm

[Joe Meazle]

You're right Joe not much traffic over this way and it is kinda cold.;) I talked with a tech at factorymation. I think I am going to be able use an undersized VFD. The amp rating on the motor is 13 and it is way oversized for a 10" tablesaw IMHO. He says that the 3hp VFD which is rated at 10.5 amps should spin it just fine. There might be a small tourque loss but I am at overkill anyway with the 5hp motor. I asked about frying the VFD he said it was unlikely since the VFD would shut it self sown if I ran into trouble. You guys see any issues with this?
Thanks,
Joe

[Joe Jensen]

You're right Joe not much traffic over this way and it is kinda cold.;) I talked with a tech at factorymation. I think I am going to be able use an undersized VFD. The amp rating on the motor is 13 and it is way oversized for a 10" tablesaw IMHO. He says that the 3hp VFD which is rated at 10.5 amps should spin it just fine. There might be a small tourque loss but I am at overkill anyway with the 5hp motor. I asked about frying the VFD he said it was unlikely since the VFD would shut it self sown if I ran into trouble. You guys see any issues with this?
Thanks,
Joe

No issue based on what I was told. The VFD I bought is self protecting. It is rated at 10amps and my motor is rated at 10.5amps. They said my VFD will deliver up to 150% of the rated 10amps for 1 min and then drop to 100%. If it's overloaded beyond that, it will shut down. If it gets too hot, it will shut down...joe