I was looking at a jointer with a 3HP 3-phase motor. I'd like to run this from my home which has 220v. Would I be able to run it on a 20A (preferably) or 30A circuit?
Can you give me an example of a "phase converter" which would be up to the task? I saw one for $89, but I couldn't tell whether it would be up to the task or not. I imagine it might be wiser to avoid 3-phase and keep looking, but I thought I would check with the experts here first.
Thanks! Bill
If it were me, and the jointers is really clean and knives in good shape and everything looks right on the bed, etc. Then I'd check on a single phase motor, for pricing. Check the frame size of the original so you can get an equivalent 1ph motor and use that as a bargaining chip. Very few people have 3 ph at home.
I like your idea. Do you know if that transition require a new switch assembly, or are these designed to be reconfigurable? If I want to actually "touch and feel" the machine, I'm looking at an
80 or 90 mile drive (each way). Then I would have to pay someone who is insured to pick it up on a "flat bed truck". I've started investigating how to get that done. Thanks, BillOn 6/15/2018 3:52 AM, Bill wrote: ...
It'll have 3Ph mag starter; you can wire it to only use the two sides of the single phase but you'll need to resize the heaters to match the single phase current of your replacement motor.
I put in a 3PH converter to bring the PM 180 planer and a 5 HP DC but it was more like 10X (not quite) the $89...it's rotary and capable of 10 HP continuous, though, not just "phantom" third phase that is likely what the $89 is from capacitors only
As OFWW says, look at seeing if can find single-phase motor used; for home use undoubtedly you can get by with less motor than 3 hp, too, and never know the difference.
On a 3hp, you'll be talking FLA of 16-20 A; you'll almost certainly have to have #10/30A circuit wiring for 240V operation; it'll be >30A at 120V which also gets to be somewhat of pain for just home workshop.
Bill, I blew the inverter on my WoodFast lathe a about a year ago and went looking for a replacement. I finally settled on a direct replacement, via Ebay. But in the process, I noticed Grizzly has several and the price is not all that bad.
Just a thought.
As for the size, depends on the draw of your motor. Again, check Grizzly.
why such a big jointer
why a jointer at all really
what you making
On 6/15/2018 7:45 AM, dpb wrote: ...
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BTW, if you do choose to go the converter route, remember the supply wiring to the converter has to be sized for the current based on the single phase supply...that has much to do with where you would want to install it to keep that run short.
I've studiously avoided any 3-phase machines although I have 4 different
3-horsepower motors in the shop -- it always seemed to be too much effort. But if you are really interested in a phase converter, I just saw a 7-1/2HP rotary converter on ebay for $389. I'd really be dubious of a $89 unit's abilities.Not affiliated or anything...
3hp on 220V is (ideally) only about 10 amps. The reality it may peak a little higher under a hard startup or if you bog down the motor.
A "good" rotary phase converter is the way to go if you think you will run much 3 phase stuff. I don't recall the derating, but its something like 30-40%. ie: Get a 5HP rotary for a 3HP motor. If all you wil ever run is a motor directly you can probably go with a cheaper static phase converter. Just remember that the derating is higher. Its best to see if the MFG says "This converter will run a X-HP motor."
The easiest way for me (and most expensive) is I have dedicated variable frequency drives on each 3 phase motor in my shop. When used 1ph in and
3ph out they have a 30% derating as well, but they give me infinite variable speed control. Most are on CNC machines where a 0-10VDC analog power signal controls frequency and rpm. Others I just use the controls on the VFD. With most half decent 3phase motors you can run from half speed (frequency) to double speed without them tearing themselves apart. If they are inverter rated they may handle more. If you have one of those fancy new washing machines you probably have a high speed 3 phase motor controlled by a VFD already. You just didn't know it.Anyway, even with the parasitic losses it will probably run just fine on a 20 amp 220V circuit. Should be absolutely no issue at all on 30 amp.
I think 1HP is roughly 750 watts. I always figure 800 and then add a fudge factor on top of that for safety.
3 X 800 = 2400 watts. 2400 / 220= 10.9 amps.You will have some loss from your phase converter, heat, wire, etc. Still with nearly double the fudge factor...
Odds are your 220V is really closer to 230-235 anyway.
Thank you Bob, and to everyone else who responded concerning my question! Your posts are helpful and informative, and will form a permanent part of my ongoing education regarding related matters.
Bill
dpb gave some great advice. I don't know what type of a switch is on the jointer so it would be hard to say, there are so many variables that I would ask the guy first what he has and a picture if possible.
an electrician or you could rewire the control circuit, but you would have to change the overload heaters for the 1ph motor and you would also have to see what the switch was rated for, as the contacts might be undersized for the motor amperage. The contacts should be inspected to see what kind of condition they are in, not burnt, not badly pitted or they would require changing out anyhow. and depending on the age and brand it might limit what you can get in an electrical supply store. WW Grainger has an online catalogue that can help if you know what you are looking for.
Also, if you can tow, then a one way trailer could be used, but you would have to verify that, and it would be easier to get it in a trailer than on and off a flat bed.
3HP is a lot for a home shop jointer. An 8" jointer needs only 1HP.
Agreed. Single phase 1hp motors can be had for $150, there abouts. A switch is a nominal cost.
As to the jointer's 3ph motor, sell it on Craigslist, if you can, or for scrap metal - about $5. Might can sell the 3ph switch, alone, also - $25?
Sonny
In the US, your 220V is even properly called "240V" (twice 120V). ;-)
3HP on a 240V circuit is no problem at all. My Unisaur has a 3HP motor and I have it on a 20A circuit (12/2). 30A is overkill.On 6/16/2018 9:11 AM, snipped-for-privacy@notreal.com wrote: ...
They're using good-efficiency motors to get that; an off-the-shelf inexpensive or particularly an older used may not...I was deliberately being conservative.
On 6/15/2018 11:57 PM, OFWW wrote: ...
3ph is virtually certain to have magnetic starter; a NEMA 1 is rated 3hp single phase; I'd be extremely surprised if the jointer he's looking at has a NEMA 0 although is possible; that would be the question to ask.The question of vintage and availability of heaters is a good one altho most old models of the usual manufacturers one can find replacement heaters for or others will cross.
But 3HP is only ~2400W. A 20A 240V circuit has 4800VA available. Piece of cake.
But included on the jointer itself? I wish I could see pictures of it. He didn't say if it was an 8,10,etc inch jointer
The jointer could have a low voltage SP switch, 24v, 110v, or 220v depending on the coil in the mag. For some reason in the back of my mind I keep thinking of a 3p switch with overload heaters, fed by a 3p knife switch fused or non fused. I have seen a lot of weird things in my day.
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I would certainly expect a one-unit starter, yes, with just remote push button switch mounted somewhere on the machine.
Wouldn't ever dream of buying without at least pictures and details, certainly, but my expectation until shown different would be something similar to
which is picture of what Rockwell/Delta used for years and years and years...there will be a mag switch besides, yes, but this kind of arrangement is what I would certainly expect.
I bought a dozen or so of these puppies used/reclaimed off old machines
30 yr or so ago and retrofitted them to everything in the shop 240V. Still have a decent stash... :)Many single-phase machines did come with mechanical switches, true, but it's pretty-much unheard of in the 3ph world.
Now again, if this started out as something else and was retrofitted, then anything is possible, granted; I was just presuming it's an old OEM setup from somebody; Crescent, Rockwell, Oliver, ...
On 6/16/2018 11:24 AM, dpb wrote: ...
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I just now noticed somebody removed the other two heater blocks from this one to use it on single phase; there's no need to do that, just jumper the neutral (L2) and leave L3 empty (or even with the heater there; there's just no connection so totally immaterial).
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