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10-18-2007, 11:14 AM #1
I have a sewing machine 1/3hp 400W motor that currently runs from 220V @3 PHASE, and I want to convert the motor to run from 110v single phase.
Can anyone please advise me on the best way of doing so? What size of capacitors is better to use for this conversion?
10-18-2007, 11:43 AM #2
You could build a static phse converter, but you would have to input 220V, not 110V.
There are some VFDs that take in 110V, and can output 230V 3 phase. That is an option if you only have 110V available.
If you only have 110V available, it might make more sense to change the motor.
10-18-2007, 12:02 PM #3
This is an ideal candidate for a VFD that uses 110 volt single phase in and 220 3 phase out. Such an unit would be the Westinghouse TECO FM50-1P5.
10-18-2007, 01:38 PM #4
What Terry said.
10-18-2007, 10:07 PM #5
10-19-2007, 04:23 AM #6
Tramvay, do you have any wiring diagram, or description of the wiring of this motor?
My guess is an step up transformer, and a suitable cap. will do.
10-19-2007, 11:26 AM #7
My heavy machines all use 110 v single phase power. It might be just as cheap/ easy to find a large sewing machine service center and see if they would trade motors with you.
10-19-2007, 12:17 PM #8
DAG S K, that another story, I don't have schematic, and even the original manufacture doesnt seem to have it. But i think the variable freq. drive should do it.
10-19-2007, 02:32 PM #9
I see those single phase sewing machine motors/w clutch on Ebay regularly.
10-25-2007, 07:59 PM #10
This seems like the right place to ask this. We've just acquired a Milwaukee Model H ( see the whole story here ) and need to run it off 110. The guy who's smarter than me thinks we can just replace the coil in the starter box with a "464-1" (where now it's a "464-2", I have more details than that.) I think that will get the starter box going, but maybe not the rest of the deal done.
Looks like the TECO FM 100 will run our 5 hp Westinghouse (vintage 1941) but that's a $250 add on for a mill we know nothing about. And won't until we get the motor to turn.
10-26-2007, 04:49 AM #11
I have tried a few frequency converters, and the
Brand DTC Lenze has been resonable easy to set up. Those I have used has been made for 230V single phase in, and 3 phase out.
10-26-2007, 10:07 AM #12
Let me get this straight. You want to run a 5hp 3 phase motor from 120vac single phase? I know of no VFD that will handle that. If 120v single phase is all you have, then you are in trouble. I have not seen any single phase 5 hp motors. In looking at your shop pictures, I find it hard to believe that you don't have 230 volts available.
10-26-2007, 07:22 PM #13
Thanks for the responses. We've plenty of 220v 3 phase power.
The problem was that the coil (464-2) in the starter box was too weak to engage the switch, or something else wasn't cutting the mustard. The motor would turn lethargically for a few seconds and then pop the breaker. The other problem was that we hate wiring things.
One leg of power goes up to the start-stop switch and then back down to the coil, where it happily joins the rest of the power if the switch closes.
The thinking was that the coil was meant for 440v to go into it and not 220. Someone theorized there must be a "464-1" coil out there that could help us. I was tasked with finding one.
Research into the matter on another thread in the forum , about getting a Monarch 10EE going, seemed to reveal that the 464-2 really was the correct coil for 220v 3 phase power to a Cutler Hammer starter box, and that 440v coils were type 404-3.
The other knuckle buster claims to have converted the 5 hp over to the low voltage configuration, per the series-parralel diagram. But now I'm thinking this thing might have been running off 220v back at MIT, and maybe my partner only reconfigured the 5 hp back to the high voltage circuit.
So there's something else going on in there, probably. I'm not the one doing the wiring (what with my erratic habit of referring to 220v 3 phase as 110v single and all that's probably a good thing) which adds to the confusion. When we get it spinning I'll post and tell you what ended up being the trouble.
10-31-2007, 01:39 PM #14
Pierce? Never seen a 5hp single phase motor??? Most air compressors have one. Mine does, plus there is another motor laying around at my dads shop. I thin 7.5 is the biggest you will find in single phase.
10-31-2007, 02:28 PM #15
Single-phase capacitor start/capacitor run motors are now available in 5, 7.5 and 10 HP sizes, and those are "real horses", too, not "Sears-Roebuck horses".
For many residential installations, 7.5 HP single-phase motors make sense, where the owner's hobby truly requires a large compressor.
10 HP single-phase is iffy, unless the residence has a 200 amp service.
10-31-2007, 07:29 PM #16
If you have a motor designed to run on 440 volts and you convert it to 220 volts, the motor starte will have the wrong heaters installed in it and it will trip before the motor comes up to speed.
It does this becasue since you have halved the voltage, you now double the curretn draw. You either need to change the heaters in the start contactor to ones that carry twice the current, or adjust the setting on the trim pots if it's allowable, or swap the contactor out to one that can handle the current.
On the sewing machine post above, we have 30+ industrial machines in the shop. If the motor does not do needle positioning, etc, it's far cheaper to simply swap out the 3 phase motor for a single phase clutch motor.
If you need the positioning, auto backtack, auto cutoff, etc, you need to use a phase converter. A static converter won't handle the rapid motor reversals required.