3 phase conversion

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Blog entry by Manasseh posted 12-09-2010 05:30 PM 1501 reads 0 times favorited 11 comments Add to Favorites Watch

OK all you LJers out there that are smarter than me,

And that should be most of you. I have an opportunity to purchase at a good price a 3 phase 10hp belt sander. The belt is about 8ft long by 8in.

My questions:

1) Has anyone gone through the trouble of getting 3 phase electricity into a residential house? If so, how did you do it?

2) What is the cost of getting 3 phase into a residential home?

3) If anyone used a converter, how did it affect your equipment?

Any and all comments welcome.

-- Someday I will be more than a sawdust wisperer

11 comments so far

View dbray45's profile


3147 posts in 2195 days

#1 posted 12-09-2010 05:48 PM

Had 3 phase in the house when I was a kid and worked with it for many years commercially. Different billing and you have to balance the loads. When you have a 3 phase environment, all of your 3 phase equipment will be hard wired to a box, receptacles are expensive. When you wire a piece of equipment, and you turn it on for the first time, stand back. If it is running in reverse, change two of the leads —if lead 1 is going to A; 2 – B; 3 – C then change 1 – B; 2 – A; C – 3 and the motor will reverse direction the way you want.

For all 3 phase equipment, wire lengths have to be maintained. You cannot have one lead a lot longer longer than the other two or you could drop phase and your equipment will become toast. Speak to an electrician and the power company before you commit. I worked with it for years and it can have it’s issues. If you are in Canada, can’t tell you because I don’t know the power there except that it is 50hz versus US at 60hz cycles.

-- David in Damascus, MD

View rustfever's profile


716 posts in 2728 days

#2 posted 12-09-2010 06:00 PM

3 ph is normally not available residential areas. To get 3 ph electricity, you will need to go to your service provider. Costs may include most of (or all of or even more of) the following. a] utility engineering fees. b] running new/additional wire(s) from nearest suitable source to the pole/vault at you house. c] provide and set a new transformer. d] new wires from street into a new electrical enterance panel. e] new 3ph sub-feed electrical panel f] Did I mention delays for engineerining? g] Did I mention $$$...? h] And don’t forget electrical permit(s) from local jurisdictions. i] did I mention minimum monthly use (or stand-by) charges?

One small business for whom I built in 2023, was quoted over $20k to run service about 1.5 miles into his new business.

Don’t mean to be bearer of bad news, but cost may be at least several thousands of $$$, even if you have 3 ph running past your home.

-- Rustfever, Central California

View John Ormsby's profile

John Ormsby

1283 posts in 3155 days

#3 posted 12-09-2010 06:02 PM

Putting in a phase converter is the normal way to go. There are a few options. I installed a Kay Industries converter. Phasematic is another brand and type. It is very important to make sure you get a converter that will actually start your 10 HP motor. There are a lot of companies out there who give out wrong info. Also, is your motor a soft start or hard start motor?

-- Oldworld, Fair Oaks, Ca

View longgone's profile


5688 posts in 2726 days

#4 posted 12-09-2010 06:18 PM

I had a chance to buy some 3 phase tools ( tablesaw and planer) a couple of years ago that were very affordable. After checking with an electrician I changed my mind. Expensive to set up and definitely overkill for my home shop even though I had enough room. I guess you have to ask yourself if you really need this much power and size for your home shop even if you can set up a converter …they are not cheap either.
Good Luck

View shipwright's profile (online now)


7080 posts in 2216 days

#5 posted 12-09-2010 06:20 PM

Here in British Columbia, If you have three phase on the pole, and it’s always been available anywhere I’ve lived, you pay to bring it to your shop and then get a break on your power bill for three of four years based on usage to help recover the cost. That’s the arrangement BC Hydro used to have anyway.
For a small shop like mine it was cheaper to convert. I got a Roto-Phase converter for around $2000 that would run about 20 Hp at one time and you could not tell the difference from line three phase. I’d do it again in a heartbeat.

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees.

View Stormin's profile


193 posts in 2207 days

#6 posted 12-09-2010 06:48 PM

As an electrical contractor we have installed phase converters which work pretty well they do take up a lot of space. We have been using a device called an Variable Frequency Drive You can feed it with 240 volt single phase add a jumper and you have 3 phase power also you can control the speed of your motor and it also has over current protection . The one thing that is important is that these devices are rated in KVA and you have to match the motor to the drive plus a bit because of the conversion . Tell the supplier all the info and they will let you know the size required.

-- I started off with nothing I have most of it left

View canadianchips's profile


2307 posts in 2415 days

#7 posted 12-09-2010 06:54 PM

You need to do a cost comparison of:

A. Buying a different 10hp motor vs 3 phase converter.
Typically you need to use a large amount of electricity before the conversion is cost efficient.

-- "My mission in life - make everyone smile !"

View Billinmich's profile


238 posts in 3149 days

#8 posted 12-09-2010 08:08 PM

I have 3ph converter in my woodshop.I only have a 12 ” jointer hooked up but looking for something else in 3 phase.My converter states I can run up to 15 horse total as long as I don’t start machines at the same time.

-- Bill in Mich

View Manasseh's profile


122 posts in 2220 days

#9 posted 12-10-2010 01:35 AM

Thank you everyone for the imput. I am discovering the cost part of this little project. I am going to go with a converter due to the cost of bringing 2 phase to the house in a residential neighborhood.
If the converter buying isn’t too costly, then I will do that.
I have decided not to get another motor.
I just don’t want to pass up a good deal.

-- Someday I will be more than a sawdust wisperer

View Manasseh's profile


122 posts in 2220 days

#10 posted 12-13-2010 11:13 PM

A final update. NO 3 phase electricity is around me. At over $100,000 to bring it to my house, that option is WAY OUT. Rustfever was correct about the money. Next option was for a converter. At about $2000, that wouldn’t be cost efficient enough for just one piece of equipment.
So, I will not be getting this sander. I could use the money other ways for equipment that meets my needs now and in the future using the electricity I am using now. Priorities.
Thank you everyone for contributing to this blog. I really enjoy figuring things out as well as knowing how things work. So, that makes this blog a success.
Someday as i get closer to retirement, I may build a shop. When I do, I will make sure 3 phase electricity is available.

Have a happy holiday everyone

-- Someday I will be more than a sawdust wisperer

View GaryL's profile


1094 posts in 2248 days

#11 posted 12-13-2010 11:33 PM

10hp would be a tough pill to swallow. I got a good deal on a PM90 3 phase lathe but it’s only 1hp and a VFD was only $150 for 1hp.

-- Gary; Marysville, MI...Involve your children in your projects as much as possible, the return is priceless.

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