[jlmccuan]

As the title says, I need to run a 3 phase 10 HP 220V electric motor with my 200A 220 single phase service. I also need speed control. Of course, always cheaply, if possible. Can any VFD with the correct rating be used for phase conversion? My application would draw litte amperage at slower speeds and would always be ramped up slowly. It is a blower without much weight, so the main load develops as the speed reaches max rpm.

[diyengineer]

I'm guessing you will need a rotary phase converter. Not cheap to buy, but if your crafty you can make your own but probably not cheap cause you have a 10HP larger motor.

I'm stuck in your same boat exactly except i have a 5HP 3 phase motor i need to run.. On a budget.

[jlmccuan]

I'm only running 2 HP now on single phase, but I need to go to at least 5. I figure if I set up for 10, I'm safe as I can't imagine ever needing this rig to require over 10HP. If it's really a big jump in cost and effort, I can back off on the HP requirement.

[diyengineer]

G5843 Static Phase Converter - 3 to 7 HP

Cheapest solution ive found yet. Notice you get 70% continuous HP and 90% intermittent HP for the first 15 minutes. Cant really beat that for $220 bucks.. I have a big 5HP motor i may try it out on..

For the price it would work well.

I'm only running 2 HP now on single phase, but I need to go to at least 5. I figure if I set up for 10, I'm safe as I can't imagine ever needing this rig to require over 10HP. If it's really a big jump in cost and effort, I can back off on the HP requirement.

[jlmccuan]

I have to have variable speed, too. The ad says for use with motors without digital controls, so how can I vary speeds?

[Karl_T]

I use a 10 hp VFD off single phase on my lathe, no problem.

The first VFD I bought had phase sensor detection and wouldn't run on one phase so I had to trade it in.

Karl

[jlmccuan]

Could you give more details on your setup?

[Karl_T]

A lathe is just a bit more involved than a blower. For your application, L1 and L2 from your electric service. T1,T2, T3 to your motor. Personally, I'd use a small switch placed conveniently for on/off an put the VFD in a panel someplace. The VFD can then be programmed to turn on based on the switch and ramp up to speed.

Karl

[jlmccuan]

So, pretty much any VFD rated above my motor could be used connected like this to control speed as well as convert from singe to three phase?

[Karl_T]

yep, just stay away from the high end ones that are likely to have phase loss detection.
You don't need to oversize for what you're doing, just get a 10 horse VFD. But undersize won't work.

Karl

[Geof]

....You don't need to oversize for what you're doing, just get a 10 horse VFD. But undersize won't work.

Karl

Read the specs carefully. You need a VFD that can accept single phase input and output 10 hp. You may have to get one that is rated something like 15hp when running from a three phase input because they are normall derated on a single phase suply.

[mactec54]

jlmccuan

There is a company that is making a 220/240 single phase to 220/240 3 phase for 10Hp, they would do the job for you just fine
Here is a link to 15Hp but they make a 10Hp

http://cgi.ebay.com/15-HP-PHASE-CONV...item20b5666d30

[diyengineer]

jlmccuan

There is a company that is making a 220/240 single phase to 220/240 3 phase for 10Hp, they would do the job for you just fine
Here is a link to 15Hp but they make a 10Hp

15 HP, PHASE CONVERTER VARIABLE FREQUENCY AC DRIVE, VFD - eBay (item 140482342192 end time Dec-04-10 07:34:23 PST)

That is really cool, i didn't know they made a single to 3 phase VFD for that large of motor. Except the price is a massive drawback. You could make your own rotary converter for that price if your crafty.

[mactec54]

diyengineer

If you look at the long term the VFD no matter what the cost is, it is still much more effcient, than any rotary will ever be, Plus you can control the motor, The only true phase converter worth having is a Phase Perfect

[diyengineer]

diyengineer

If you look at the long term the VFD no matter what the cost is, it is still much more effcient, than any rotary will ever be, Plus you can control the motor, The only true phase converter worth having is a Phase Perfect

Very True, it would be a solid investment. The 5HP motor i have is just for a air blower that needs 3 phase. As long as it turns on and off i would be happy.

jlmccuan-

What is this motor going to be used for anyways?