Motor 120V 3-Phase

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If the motor in question is really 120 volt then it isn't three phase. The phase to phase voltage of three phase power that will provide 120 volts relative to the center tap of a wye connected transformer set is 208 volts. I've been doing electrical work in heavy industrial to home environments for over thirty years and I have never seen a 120 volt three phase motor. 120 volt service is pretty much a north american thing. I have worked a lot of places and I have never encountered a three phase voltage that was 120 volts when measured phase to phase. -- Tom H
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only
center-tap
120V
Tom, I've been doing electrical work in "heavy industrial to home environments" for 27 years, and I've never seen a 120 volt 3 phase motor either, nor a 3 phase 120 volt (line-to-line) system..............but if you look at NEC (2002) Table 430.150 it does indeed show FLC's for 115 volt 3 phase motors 2 HP and under.........so, evidently, they must exist somewhere for some special purpose. Also see the commentary at the beginning of Article 647 in the NEC Handbook........evidently the motion picture and tv production industry (NEC Article 530) has been using a 60/120 volt 6 phase wye connected system for some time, for noise reduction when they set up to shoot in "dirty" electrical environments. It's being referenced as "balanced power" or "technical power." Seems the 2002 NEC (new) Article 647 is now permitting these systems for just about any sentitive electronic equipment requiring isolation.........computers, medical equipment, etc.
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On 11/2/03 9:37 PM, in article x3kpb.90484$ snipped-for-privacy@twister.tampabay.rr.com, "volts500"

Would it be practical for the original poster to use a static phase converter for this motor? Maybe he'd be better off to just buy a regular single phase 1 hp motor money wise.
Dean
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I think the OP has a $5 boat anchor. Have you ever seen a converter with a 120 volt output?
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On Sun, 02 Nov 2003 22:04:02 -0600, Dean Hoffman

My apologies for not posting the full specifications on the plate. They didn't make sense to me then or now. Here goes.
MARATHON ELECTRIC Wausau, Wisconsin 54401 Cat No. K049 Model 6V556T17D2130D P FR 56 PH-3 Type TS
(Left Hand Column) ( RH Column) FLA 1.4     Hz 60 SF 1.15 HP 1 SFA 1.6 RPM 1725 CODE L VOLT 575
Single Voltage L1 L2 L3 T1 T2 T3 (wiring diagram)
FR 56 AMB -40 deg INS-B3 DUTY- Cont. DES B
Looks like I goofed on the voltage (575V) but does such a voltage exist in a 3 phase industrial power source?
The motor has its own attached control box with an ordinary toggle switch hooked with three conductor 16 ga rubber insulated cord, but no power plug connector. It doesn't look right for a 575V system but there it is.
I have already wired an ordinary three prong household plug to the cord but I have not stuck that into any outlet yet to test it. That 575V spec gave me reason to ask first. That was sometime ago until I thought about asking this newsgroup.
A new 1 hp motor costs >$200. $5 for one at a garage sale is a safe bet and if it doesn't work its no loss. And darn, there is not a scratch on it from power on usage so its practically new.
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wrote:

Yes, usually in Canada.

Sure it is. The FLA (Full Load Amps) is only 1.4 amps. 1.4 amps x 125% 1.75 amps The 16 gauge wire is sufficient for 1.75 amps, as long as the wire is rated for 600 volts.

Don't bother, it's not going to work.

Sorry, but you still have a $5 boat anchor. You may be able to find a 575 volt 3 phase converter, but if you can, I suspect that it will cost as much as a new 1 HP (120 volt or 240 volt single-phase) motor. Keep trying, you should be able to find a used motor out there..........except this time don't buy it unless it is a 120 volt or 240 volt _single-phase_(PH-1) 1 HP motor.
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the problem is the lack of 3 phase power, not the voltage itself... how did you connect it to an ordinary house plug? an ordinary 3-prong house plug has 1 ground, 1 neutral and one hot. you need at least 3 hots for this motor...
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you
3
somewhere
tv
phase
to
647
No, Tony, only an electronics "wizahd" like you would confuse BPL with "clean" 120 volt power. Wouldn't surprise me if you told the OP to wire the motor up with some Cat5.
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snipped-for-privacy@jj.com Wrote:

On the street in back of mine there are three 13.9 kilovolt lines on the top cross arm of the poles. Every third transformer is tapped off of the same phase. That is undoubtedly because the area has some apartment houses but the point is that the network often brings all three phases to a residential or even a rural area in order to balance the load on the supply. PEPCO, Allegheny, and VEPCO all provide three phase service to much of their service area. They will not supply a three phase transformer setup to supply a service unless the demand justifies the expense. If the demand expected on that service will not justify the expense some power companies will supply three phase distribution voltage as the service to a customer owned transformer. -- Tom
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Wrote:

only
center-tap
120V
well, then I guess every network is different. Where I live, I'm pretty sure we don't get 3 phases (I have no idea how it is in a building, I live on a street with houses only). On my street there's no transformer, the phases get split somewhere else.
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Wrote:

itself
sure
This is turtle.
You have them somewhere but maybe you have transformer bank / Mini-Substation on the ground some where to feed the hold area.
TURTLE
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possibly. but I don't see how you'd use them in a residential area.

you can't since you only get 2 phases in a house and a 3 phase motor needs 3 phases.
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Never heard of a 120V 3 ph motor. Most 3 PH has three legs of 120V coming in or in some cases one leg has 220V called Delta ph. In any case there are converters out there that work but cost way more then $5.
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Go buy a $500 Variable Frequency Drive. Most will accept single phase in and will produce a three phase output. Set the parameters for 120 volt motor and you are set! Either that or sell it for $5 on a garage sale and buy a motor that you can use! Greg
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this is turtle.
I have a 480 volt Step down transformer to 120 volts that you could try to fix to do something or someway to do something for your 120 volt 3 phase 1 horse motor. I don't know how you could wire it up but it's cheap and i only want $2.00 for it because it has $2.00 worth of copper in it. Now you only need 3 phase 480 volt service to your home and you have it here. I kept it for it has a tap off the side for 480 volt 3 phase to go to rooftop condenser fan motors of 230 volt 3 phase fan motors which 4 will run off it. I don't know what the 120 volt 3 phase taps is doing on it.
Hurry up it's going fast for I have only had it 5 years now and looking for a home. Awwwwwwwwwwww E-Bay they can find a home for anything.
TURTLE
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On Sunday, November 2, 2003 at 12:08:05 PM UTC-6, klm wrote:

With all due respect, you can find a 120V 3 phase motor in many Carrier and Payne brand furnace boxes. The fan blower motor is 120v ECM, electronically commutated motor, which is a 3-phase motor with an attached speed controller. These were originally built by GE. GE then sold off the motor design.
The motor model number is: 5SME39SL0122 or 5SME39SL0310 or HD52AE120
Remove the rear section of the motor, retained by two screws, then disconnect the 3-wire connector between the motor and the speed controller.
This leaves the front section of the motor, which is a 1HP 3-phase 120v motor
Connect a Reliance Electric SP500 VFD model 1SU11001 (120VAC input, single or 3-phase), 120VAC output 3-phase.
Connect a regular grounded line cord to the RS inputs (black and white), green to the grounding screw, and the motor's 3 wires connect to the RST output terminals.
Plug in the controller, let it run its self-test, then press start. The motor will immediate spin up. Press stop, then Reverse, then Start. The motor will follow, and reverse rotation
Pressing the up or down buttons will vary the motor speed up to about 1800RPM.
You can provide a 5k pot for speed variable, or use 0-10VDC speed control, or 0-20ma speed control.
Long and short of it, the variable speed fan blower motors in the Carrier and Payne (high efficiency) furnace units are 3-phase... just remove the rear speed control section that comes on the motors.
These motors run around $800 retail, new, yes, horrendous, but find a replaced unit and grab the blower motor.
The furnace inducer is also variable speed, 1/5hp, and the outdoor compressor fan unit contains a variable speed 1/3 hp 3-phase motor, both having similar speed controls on rear end.
The outdoor fan is 240v, however, and the inducer fan motor is 120v 3-phase.
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Sorry, meant to write 'connect notor to UVW terminals'
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