# 220 Volt Question



## k1pyp (Feb 26, 2014)

Some mills use 220 v single phase motors so I was wondering, if you didn’t have a 220 volt line at your house, can a voltage converter like this one </SPAN>http://www.amazon.com/3000-Watt-Voltage-Converter-Transformer/dp/B000AUKVWM/ref=pd_sim_sbs_e_5?ie=UTF8&refRID=06DY4S4BCXHP6SRWCW7T</SPAN> be used? </SPAN>
I think it will work but I want to make sure.</SPAN>

Thanks.</SPAN>

Paul</SPAN>


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## John Hasler (Feb 26, 2014)

k1pyp said:


> Some mills use 220 v single phase motors so I was wondering, if you didn’t have a 220 volt line at your house, can a voltage converter like this one http://www.amazon.com/3000-Watt-Vol...m_sbs_e_5?ie=UTF8&refRID=06DY4S4BCXHP6SRWCW7T be used?
> I think it will work but I want to make sure.
> 
> Thanks.
> ...



It should work for modest sized motors but are you certain you don't have 220?  That would be very unusual.


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## k1pyp (Feb 26, 2014)

John Hasler said:


> It should work for modest sized motors but are you certain you don't have 220? That would be very unusual.



I am only looking within my garage. I assume that the 220 v plug is different from the 120 v plug and all the plugs (including washing/drying machine) look like 120 v.


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## abendstern (Feb 26, 2014)

You should already have a 220V connection for your dryer. A big socket  with at least 3 prongs
shaped like a Y . Like This:

 |
/ \

You could branch off this circuit, but dont run you machine and dryer together. Or make and adapter with a visit to your Home Depot or equivalent.

What does the plug from you machine look like? Maybe something like:

  o                  o
_  _     or      _   |


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## twstoerzinger (Feb 26, 2014)

Hello Paul,

Before you try to go down the voltage converter path - confirm that you really don't have 220V.

I agree with John in that a home today without 220 V power would be very unusual - especially in California, where you have central air conditioning. If you have central AC, then 220 V power is pretty much a certainty. Someone familiar with home wiring systems could look at your entrance  breaker / fuse and tell you in 10 seconds if there is 220 V power. Perhaps you have a relative, neighbor, co-worker that could take a look.

You are right in that 220V outlets look different from 120V.
220 V outlets are typically only installed where 220V is expected to be used  - such as at an electric range, electric clothes dryer, or an electric oven.
I can see where there would not be a 220V outlet in a garage unless a previous owner had a welder or some other high amp device.

220V outlets also look different depending on the amp rating. This is done so that you don't try to plug in a device which draws more power than the rating of the wiring / breaker which is installed.

Assuming there is 220V power in your house, adding a 220V outlet may not be a big deal.
Its not a "first time project" though. Find a qualified person to do the work. Show him the machine to be connected so that the proper breaker / wiring / outlet is installed.

Terry S.


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## k1pyp (Feb 26, 2014)

The 220 v outlets are in the kitchen and by the AC. My washer and (gas) dryer plugs in the garage are 120 v. </SPAN>
The reason for the voltage converter is that I thought it would be cheaper to buy one than to have an electrician add a 220 line in the garage. For less than $70.00 for a 220 outlet with a converter vs cost of electrician. How much does it cost to add a 220 line by a licensed electrician?</SPAN>


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## twstoerzinger (Feb 26, 2014)

You are right - you won't get an electrician on site for $70.
How big is the motor on the mill? If it is a 1 HP or less, you might be able to use the transformer.
Most residential outlets are 15 amp (20 amp for a washer or other large appliance).
A 15 amp socket can deliver around 1700 watts without tripping the breaker.
Look at the rated current on the mill motor. Then, double it to get the current at 120 V.
Terry S.


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## k1pyp (Feb 26, 2014)

twstoerzinger said:


> You are right - you won't get an electrician on site for $70.
> How big is the motor on the mill? If it is a 1 HP or less, you might be able to use the transformer.
> Most residential outlets are 15 amp (20 amp for a washer or other large appliance).
> A 15 amp socket can deliver around 1700 watts without tripping the breaker.
> ...



Good to know about the limit on outlet. I don’t have a mill yet but am in the process on finding the “right” one. If I can use a converter to run a 220 v motor (<= 2hp), it opens up more options since I am not limited to 120v motors. The mill I am looking for is just for home hobby use and it won't go over 2 hp so 1700 watt is plenty.</SPAN>


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## CluelessNewB (Feb 26, 2014)

> How much does it cost to add a 220 line by a licensed electrician?



Depends on lots of things.

How far is it from the breaker box?
Do you have room for another (double) breaker in the box?
Is there reasonable access to run new wires?  
What brand & style breakers does your box take?  (Obsolete or oddball stuff can add to the price.)
What do electricians charge in your area?

The actual work to add a 20 amp 220V circuit is the same as a new 20 amp 110V circuit.  

Materials alone would probably get near the $70 mark.  

That said I still think adding a new 220 circuit is a better idea in the long run unless you have plans to move in the near future.    

Personally I think the claim of 3000 watts for that transformer is dubious at best, that would be a bit over 27 amps @ 110.   Even if the transformer can do that your normal 110V circuit will not!


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## k1pyp (Feb 26, 2014)

CluelessNewB said:


> Depends on lots of things.
> 
> How far is it from the breaker box?
> Do you have room for another (double) breaker in the box?
> ...



I am assuming electricians are at least as expansive as plumbers (they are expansive around here) . At this point, I am just looking and pursuing options for a 220 v outlet (if needed). </SPAN>
Since I am mainly interested in a motor less than 2 hp (less than 1500 watt), the converter should be fine.


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## Ed W (Feb 26, 2014)

Also keep in mind that many single phase induction motors (especially those about 1.5 hp and less) can be easily rewired to run on 120 volts.

Ed


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## Dave Smith (Feb 26, 2014)

Paul--I have the same problem as you except mine is much worse---my breaker panel entrance is on the front of my house and my two separate detached shops are on the rear  side--neither shop has 220 wiring and only one line of 110 services both shops--that works only nice for lights and small motors--my AC unit is on the rear side of my house but I'm sure it is only for approx 35 amps--I need 220 50amp for my welder and I need 220 for my air compressor and one lathe and two mills--so I will have to run approx 200 feet of underground cable (probably at least #6 or larger)--I figure my cost of materials will be $400-$800 and I can't justify that expense till I sell some things---anyway-If I were you I would definately put the 220 wiring in your shop instead of messing with 110 headaches--they won't help when you need 220 for welders --compressor and other shop devises---you didn't say if your shop or garage is attached to your house or not---hopefully your service panel is in a better location than mine is--I don't even have a basement or crawl space to run it under my house--I will have to go up and through the attic area to get it to the back side of my house----Dave


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## k1pyp (Feb 26, 2014)

Dave Smith said:


> Paul--I have the same problem as you except mine is much worse---my breaker panel entrance is on the front of my house and my two separate detached shops are on the rear side--neither shop has 220 wiring and only one line of 110 services both shops--that works only nice for lights and small motors--my AC unit is on the rear side of my house but I'm sure it is only for approx 35 amps--I need 220 50amp for my welder and I need 220 for my air compressor and one lathe and two mills--so I will have to run approx 200 feet of underground cable (probably at least #6 or larger)--I figure my cost of materials will be $400-$800 and I can't justify that expense till I sell some things---anyway-If I were you I would definately put the 220 wiring in your shop instead of messing with 110 headaches--they won't help when you need 220 for welders --compressor and other shop devises---you didn't say if your shop or garage is attached to your house or not---hopefully your service panel is in a better location than mine is--I don't even have a basement or crawl space to run it under my house--I will have to go up and through the attic area to get it to the back side of my house----Dave



I have an attached garage (front of the house) and my service panel is in the back. I probably need to add a 220v line in the garage in the future. </SPAN>
For now, I am just looking for a mill, and an ability to add a quick and cheap 220v outlet will expand my search options. When I consider the cost of a mill, I need to consider the cost of adding a 220 v outlet so the less I spend on the electrical work the more I can spend on a mill.</SPAN>


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## jim18655 (Feb 26, 2014)

If you have a dedicated outlet in the shop area you could rewire it for 220V. All you would need is the receptacle and new breaker.


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## John Hasler (Feb 26, 2014)

jim18655 said:


> If you have a dedicated outlet in the shop area you could rewire it for 220V. All you would need is the receptacle and new breaker.



That would violate code by making the white wire in the circuit hot.  White is, for very good reason, reserved for grounded conductors.  Besides, he'll want 120 in the shop for other stuff.


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## Walltoddj (Feb 26, 2014)

John Hasler said:


> That would violate code by making the white wire in the circuit hot.  White is, for very good reason, reserved for grounded conductors.  Besides, he'll want 120 in the shop for other stuff.



Code calls for marking the wire most wrap black electrical tape on both ends to show it's hot. Been done that way for years. Now most are going to a 4 wire which is a waste neutral and ground go back to the same place it's to be sure it's grounded.

Todd


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## John Hasler (Feb 26, 2014)

Walltoddj said:


> Code calls for marking the wire most wrap black electrical tape on both ends to show it's hot.



And then the tape falls off or the homeowner messing with the circuit has no idea why it's there and ignores it.  Not a good practice at all.  I do this with cord sometimes but I use magic marker, not tape.  I won't do it with Romex or wire in conduit, though I concede that it is legal.



> Now most are going to a 4 wire which is a waste neutral and ground go back to the same place it's to be sure it's grounded.
> Todd



Not sure what you are getting at.  The grounded conductor (white) and the grounding conductor (green) are very different and the latter is always needed.  It is true that all 220V circuits don't need a neutral.  I always install one anyway so it will be there later when I find that I want 110 after all.


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## AlanR (Feb 26, 2014)

Walltoddj said:


> Code calls for marking the wire most wrap black electrical tape on both ends to show it's hot. Been done that way for years. Now most are going to a 4 wire which is a waste neutral and ground go back to the same place it's to be sure it's grounded.
> 
> Todd


It's not a waste, there are very good reasons.

The neutral does not connect to the frame or cabinet of a supplied piece of machinery, it should not, that's the job of the grounding system. The neutral and the hot wire need to be in balance for circuit load planning to function.  In the past metal conduit often supplied the ground connection, but many times conduit can be separated by accident, I've seen it many times. People hang onto conduit, pulling connectors out, forklifts hit it and so on, hence the ground wire.

Once a machine loses the frame ground a fault from the hot wire or some internal device to the frame results in a "hot" cabinet, should someone touch that and any ground (for example, a water pipe) they become a circuit and they can die.


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## jim18655 (Feb 26, 2014)

John Hasler said:


> And then the tape falls off or the homeowner messing with the circuit has no idea why it's there and ignores it.  Not a good practice at all.  I do this with cord sometimes but I use magic marker, not tape.  I won't do it with Romex or wire in conduit, though I concede that it is legal.
> 
> 
> 
> ...


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## Dave Smith (Feb 27, 2014)

I'm not an electrician but I have done a lot of factory maintenance work for about 24 years--I do know the reason that you want 4 wires going to a 220v machine is just not to run the 220 motor--but to also supply a neutral wire for a 110 plug receptical or a simple thing like a light bulb--the ground wire is not to be used for these.--Dave----*your neutral and ground only are connected and meet in your main entrance panel ---not anywhere else--an electrical inspector explained that to me, and I haven't forgotten


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## jererp (Feb 27, 2014)

I think if you are going to the expense of hiring an electrician to run a dedicated 220 circuit, you should price out the additional material cost to upgrade to a 50 or 60 amp sub-panel for your shop. 

 For those other toys that may come along.


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## TOOLMASTER (Feb 27, 2014)

Walltoddj said:


> Code calls for marking the wire most wrap black electrical tape on both ends to show it's hot. Been done that way for years. Now most are going to a 4 wire which is a waste neutral and ground go back to the same place it's to be sure it's grounded.
> 
> Todd



yup...many industrial wire jobs use all black wiring...tape up the colors


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## John Hasler (Feb 27, 2014)

TOOLMASTER said:


> yup...many industrial wire jobs use all black wiring...tape up the colors



Anything other than white or green is fine for hot wires in machine wiring.  Wire numbers are preferable to colored tape for labeling, though.  There are standards for color codes http://en.wikipedia.org/wiki/Electrical_wiring#Colour_code but the only one you can rely on completely is green or green-yellow for safety ground (and white for neutral in the USA.)

There are also standards for labeling machine wiring but you can't rely on them.


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## master53yoda (Feb 27, 2014)

John Hasler said:


> That would violate code by making the white wire in the circuit hot.  White is, for very good reason, reserved for grounded conductors.  Besides, he'll want 120 in the shop for other stuff.



I'm sorry but that isn't accurate by code.  The only wire color that CANNOT BE POWEREd IS THE GREEN wire as that is restricted to ground bonding conductors the must either be green or bare in line voltage wiring.    The white wire is hot between any switch and the light in normal 110 wiring if the power is brought into the light fixture and a wire run to the switch.    If you want you can put a red tape band on the white wire it is common practice to id both power wires but as of 2000 when i retired it wasn't code.      The white wire is noramlly neutral but when runnning a dedicated 220v only circuit code allows black white for 220v. bare or green for ground, no 110 volt usage is allowed, this is the type circuit that is run to water heaters all the time.       if you are going to use 110 out of the 220 volt circuit it must be a 4 wire circuit   bl rd 220  either to wh is 110  bare or green is ground.

I hope this clarifies the code requirements.

Art

I was a building inspector the last 10 years before I retired.


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## master53yoda (Feb 27, 2014)

Dave Smith said:


> --Dave----*your neutral and ground only are connected and meet in your main entrance panel ---not anywhere else--an electrical inspector explained that to me, and I haven't forgotten



The reason that the only place that the ground and neutral are connected together is in the main panel is that there is curent flow through the neutral under most loads.  The current flow in the neutral reduces the path back to the bonded neutral bar in the panel.    When a short in the wiring occurs it is possible that the path through you to the ground that you are standing on is a lower resistance path then the path through the neutral along with the normal load, without the clean ground path back from the case of the electrical appliance to the main panel ground you could recieve an deadly shock. 

    When running power to a sub-panel you must run a 4 wire circiut and an isolated neutral bar in the sub-panel   the neutrals all go the isolated bar and the grounds go to the added bar that is bonded to the panel box.   When using a sub-panel you do-not install the bonding strap or screw that ties the neutral bar to the panel box.   

 In our day of electronic devices a clean bonding path is very important to remove electrical noise form communiction lines,  when coaxial or bonded cableing is used it is important to only bond the cable at one end if you bond it at both ends you can get noise induced into the signal.

hope this helps reduce confusion over the ground wire


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## John Hasler (Feb 27, 2014)

master53yoda said:


> I'm sorry but that isn't accurate by code.  The only wire color that CANNOT BE POWEREd IS THE GREEN wire as that is restricted to ground bonding conductors the must either be green or bare in line voltage wiring.    The white wire is hot between any switch and the light in normal 110 wiring if the power is brought into the light fixture and a wire run to the switch.    If you want you can put a red tape band on the white wire it is common practice to id both power wires but as of 2000 when i retired it wasn't code.      The white wire is noramlly neutral but when runnning a dedicated 220v only circuit code allows black white for 220v. bare or green for ground, no 110 volt usage is allowed, this is the type circuit that is run to water heaters all the time.       if you are going to use 110 out of the 220 volt circuit it must be a 4 wire circuit   bl rd 220  either to wh is 110  bare or green is ground.
> 
> I hope this clarifies the code requirements.
> 
> ...



It may be sometimes  be legal to have white hot but it is always a bad idea.   You know that some people are going to blithely assume without checking that white wires are always neutrals.  It's a mistake, but they shouldn't die for it.  "Permitted by code" is not a synonym for "best practices".


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## woodrowm (Feb 27, 2014)

Good afternoon - Save yourself a lot of trouble and spring for the 220v outlet, I went through the same thing. It cost me $200 and is well worth it.

Thanks,
Woodrow


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## master53yoda (Feb 27, 2014)

i did a little digging to clarify the wire color requiremnts   The only wire colr requiremt (in Home wiring) concern grounded conductors 

_ARTICLE 200 Use and Identification of Grounded Conductors_ 
_Section 200.6 Means of Identifying Grounded Conductors _ *(A) Sizes 6 AWG or Smaller * 
Grounded conductors smaller than 4 AWG are to have an outer finish that is white or gray, or three white stripes along its length.  

 This marking is only required where a connection is made and the grounded conductor is present.  There are no color code requirements for POWERED conductors with the exception the wild or high leg of a delta 3 phase system.  These systems are not in common use any longer but THREE PHASE SYSTEMS DERIVED FROM A 3 PHASE CONVERTOR ARE THIS TYPE OF SYSTEM,  if you need to pull 110V out of this type of system don't do it uless you really know what you are doing ,  the voltage to ground on the high leg of a 240 volt delta system is close to 200VAC  or line to line in normal residential wiring it is deadly not only to you but any 110Volt device connected to it.      

*Orange-High Leg Delta* 
_ARTICLE 110 Requirements for Electrical Installations_ 
_Section 110.15 High-Leg Marking_ 
High leg delta systems that have the midpoint of one phase grounded are required to have that phase conductor marked with orange tape, orange finish or similar.


Sometimes we condsider what is tradition to be code, such is the case with the white neutral and using it for a power conductor what is noramlly done isn't necessarily code,  and the inspector cannot inforce what isn't code.

Art


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## master53yoda (Feb 27, 2014)

John Hasler said:


> some people are going to blithely assume without checking .



If they do that sooner or latter they wil get blown away, anyone that works eletrical needs to use a meter or not touch it,   

I have been hit hard twice in my life.   Once because I trusted someone else to shut off a 480volt breaker that one blew out a nerve in my left hand from that time on I have had no feeling in 2 fingers.    The other time was a home owner that changed a fan motor and shorted out the common terminal  to the runn winding leaving the capacitor to take a full charge.  I took that arm to arm about 300V  that for al practical purposes gave me a hear attack.    So don't ever trust that what is there is what you think it is.  Even professionals make mistakes we are human after all.


back to the original question.  Yes you can modify a 110 volt  DEDICATED circuit to 220v buy using a 220 proper rated breaker and 220 volt proper rated recepticle.    Please verify that the only resepticle that is feed is the one the you are converting to 220.   most 110 volt circuits are not dedicated circuits.    If you don't know how to verify that it is a dedicated circuit you really need to use and electrician, electrical mistakes can be deadly or have lifetime concesquences like my fingers.

Art


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## MICK1958 (Feb 27, 2014)

I have been a member for a long time, have not posted prior to today. 

It seems like the OP has been lost in the "wiring debate" ...  Let me say that I am by no means an "expert" but I would bet my next 6 checks that the OP has 220 volts coming into his home.

Secondly, I think he should buy a book at the local big box store or even Amazon and learn how to hook up two circuit breakers from his existing circuit panel. That would be money well spent. (book)

Third, If he has an inadequate circuit box, with the same book he will be able to hook up a sub panel to accommodate his needs. I cannot imagine the cost of the box, wiring, circuit breakers, wall anchors and screws, strain reliefs, staples or even conduit could not cost more than 125 dollars. 

This is not brain surgery, It is simple wiring. If he does not have the skills to follow this basic knowledge ... He probably shouldn't be messing around with metal working machines.

I need to emphasize that I am in no way poking fun at anyone. The acquisition of this knowledge about basic wiring will pay dividends to the OP for the rest of his time on this earth. 

I do not live in that foreign country (California) but, I would be reasonably sure a local person could help him for a reasonable cost, maybe even a beer.


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## Walltoddj (Feb 27, 2014)

Unless you are running single wires in conduit Romex does not come with two black wires even in four wire it's bare, black, white, and red sometimes the bare is green. In three phase and in 220v single phase no current flows in the neutral or in the ground. Residential wiring is a lot different from industrial due to the fact they use multiple single wires and pull them though conduit and they have the proper colors needed to do the job. Oh and my son is a Journeyman Electrican.

Todd


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## rdhem2 (Mar 1, 2014)

After a career in electricity, I think the advice from master53yoda  and *MICK1959* is the best.  If you are not 100% sure of yourself, hire it done.  After all, being professionally done adds to property value and desirability.  When you do it, we all wonder.


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## mixdenny (Mar 5, 2014)

Aside from all the things discussed so far, I DO NOT think the transformer in question will do the job safely anyway. This opens up another can of worms but...

This transformer converts US 120 volt power (120 volts to neutral) to European 240 volt power (240 volts to neutral). That will not work for a US type 240 volt tool, as it expects US type 240 volt power which is: (120 volts-Neutral-120 volts). The two 120 volt lines are out of phase by 180 degrees.

So this transformer will place 240 volts on a circuit in the machine that expects 120 volts, and will ground the other circuit (via the neutral) that should have 120 volts on it. 

Dennis


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## mrbreezeet1 (Mar 5, 2014)

Dave Smith said:


> I'm not an electrician but I have done a lot of factory maintenance work for about 24 years--I do know the reason that you want 4 wires going to a 220v machine is just not to run the 220 motor--but to also supply a neutral wire for a 110 plug receptical or a simple thing like a light bulb--the ground wire is not to be used for these.--Dave----*your neutral and ground only are connected and meet in your main entrance panel ---not anywhere else--an electrical inspector explained that to me, and I haven't forgotten



yes, esp. a sub panel needs 4 wire, and the ground and  neutral are kept separate, never tied together.  neutral buss bar is isolated from the metal box too.


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## John Hasler (Mar 5, 2014)

mixdenny said:


> Aside from all the things discussed so far, I DO NOT think the transformer in question will do the job safely anyway. This opens up another can of worms but...
> 
> This transformer converts US 120 volt power (120 volts to neutral) to European 240 volt power (240 volts to neutral). That will not work for a US type 240 volt tool, as it expects US type 240 volt power which is: (120 volts-Neutral-120 volts). The two 120 volt lines are out of phase by 180 degrees.
> 
> ...



If it comes with a European outlet he should, of course, remove it and wire the secondary directly to his motor (or via an appropriate connector).  The transformer itself would work ok, but it isn't the optimum solution to the problem.


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## k1pyp (Mar 6, 2014)

mixdenny said:


> Aside from all the things discussed so far, I DO NOT think the transformer in question will do the job safely anyway. This opens up another can of worms but...
> 
> This transformer converts US 120 volt power (120 volts to neutral) to European 240 volt power (240 volts to neutral). That will not work for a US type 240 volt tool, as it expects US type 240 volt power which is: (120 volts-Neutral-120 volts). The two 120 volt lines are out of phase by 180 degrees.
> 
> ...



This is very informative. Thanks.
So is the US 240 volt essentially a two-phase circuit?


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## John Hasler (Mar 6, 2014)

k1pyp said:


> This is very informative. Thanks.
> So is the US 240 volt essentially a two-phase circuit?



No.  The 240 coming into your house is single-phase.  The secondary of the transformer out by the street is center tapped.  The tap is the neutral and is grounded.  Each hot leg thus gives 120 referred to the neutral or 240 referred to the other leg.  Thus the two legs are 180 degrees out of phase, which is simply opposite polarity.  Electricians often refer to the legs as phases, but this is not correct.

Two phase consists of two phases at 90 degrees.  It is not used for power distribution.


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## CluelessNewB (Mar 6, 2014)

> Two phase consists of two phases at 90 degrees. *It is not used for power distribution.*



At least not much anymore!   http://en.wikipedia.org/wiki/Two-phase_electric_power


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## k1pyp (Mar 6, 2014)

John Hasler said:


> No.  The 240 coming into your house is single-phase.  The secondary of the transformer out by the street is center tapped.  The tap is the neutral and is grounded.  Each hot leg thus gives 120 referred to the neutral or 240 referred to the other leg.  Thus the two legs are 180 degrees out of phase, which is simply opposite polarity.  Electricians often refer to the legs as phases, but this is not correct.
> 
> Two phase consists of two phases at 90 degrees.  It is not used for power distribution.



If I understand you correctly, it seems like the motor is experiencing the same 240 v either way so why can't you use a 120-240 converter?
Obviously I am not grasping the concept.


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## John Hasler (Mar 6, 2014)

k1pyp said:


> If I understand you correctly, it seems like the motor is experiencing the same 240 v either way so why can't you use a 120-240 converter?
> Obviously I am not grasping the concept.



You can if what you need is 240 single phase.  Such a transformer may have a European-style outlet on it, though, with one pin grounded and the other at 240.  If so you will want to rewire it.  There probably won't be a center tap so you will have to either leave the secondary floating or run it European-style.

You could also rig an autotransformer from a 1:1 120V transformer, but if you knew how to do that you'd find it easier to just put in a subpanel.

Much better to just put in a subpanel.


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## k1pyp (Mar 7, 2014)

John Hasler said:


> You can if what you need is 240 single phase. Such a transformer may have a European-style outlet on it, though, with one pin grounded and the other at 240. If so you will want to rewire it. There probably won't be a center tap so you will have to either leave the secondary floating or run it European-style.
> 
> You could also rig an autotransformer from a 1:1 120V transformer, but if you knew how to do that you'd find it easier to just put in a subpanel.
> 
> Much better to just put in a subpanel.




Thanks for the info. Believe it or not, this is actually making sense to me.


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## Halteclere (Mar 8, 2014)

John Hasler said:


> You can if what you need is 240 single phase.  Such a transformer may have a European-style outlet on it, though, with one pin grounded and the other at 240.  If so you will want to rewire it.  There probably won't be a center tap so you will have to either leave the secondary floating or run it European-style.
> 
> You could also rig an autotransformer from a 1:1 120V transformer, but if you knew how to do that you'd find it easier to just put in a subpanel.
> 
> Much better to just put in a subpanel.



If the mill is wired for only 240VAC - i.e. its power cord only has three conductors (two hots and the ground), then the transformer should work fine. The mill doesn't care if one leg of the 240VAC is at ground potential and the other leg is at 240VAC potential, or if both legs are at 120VAC potential reference to ground but 180 degrees out of phase. The mill only cares if the difference between the two legs (the two current carrying conductors) is 240VAC. 

If the mill also has a 120VAC load, such as for any lights or controls, then such a simple transformer won't work because it isn't designed to provide both 120VAC and 240VAC loads measured between the current carrying conductors (the hots and the neutral). If the mill also has a 120VAC load then its power cord will have four conductors. 

The challenge I see with this transformer is changing the provided Euro/Asian Shucko round plug to a plug useful here in the U.S. Maybe the free adapter plug that comes with it does this change. Also, I don't know if the motor in-rush current will cause any issues when the mill is started.

Look at the breaker feeding the garage receptacle that you want to use with the transformer. If the breaker is 15A then you can drive a 1/2HP or smaller, 240VAC motor by the circuit according to code (assuming nothing else is on the circuit). If the breaker is 20A then you can only drive a 1HP or smaller, 240VAC motor by the circuit according to code. This assumes that the transformer does not have any loss, which it will have some. 

I say "according to code", for the NEC builds in safety factors when sizing the conductors and breakers. The circuit breaker is only there to protect the circuit conductor, and not anything that is attached to the outlet. Also, when sizing the circuit conductors for a motor-driven appliance, the full load current is determined from an NEC table and not from the current nameplate rating. All the motorized equipment I have around my house have nameplate full load current ratings smaller than what NEC specifies the circuit can to handle. Finally, circuit breakers have a time/current curve such that they don't immediately trip when the current slightly exceeds their rating. How long it takes a breaker to trip is inversely proportional to the amount of the overcurrent. 

So yea, it may be possible to drive a motor larger than what is specified by code by doing things such as minimizing loading down the motor or limiting how often it is started up, or just not continuously running the motor for long periods of time. But none of these things would be recommended by anyone (including myself) who could be in a position to be considered liable if a fire were to start. But there is nothing preventing a homeowner from making due with the wiring that he currently has until he can get a better solution - there is nothing preventing someone from plugging in equipment that  pulls a little more power than what the circuit was designed for.


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## mrbreezeet1 (Mar 8, 2014)

sorry if this was covered, but is it too far to run a new wire for a 220 V outlet from the Breaker, Or a Sub panel?
A 220 v breaker/outlet is not hard to wire at all. 
Again, sorry if this was covered.
Thanks, 
Tony


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## John Hasler (Mar 8, 2014)

mrbreezeet1 said:


> sorry if this was covered, but is it too far to run a new wire for a 220 V outlet from the Breaker, Or a Sub panel?
> A 220 v breaker/outlet is not hard to wire at all.
> Again, sorry if this was covered.
> Thanks,
> Tony



How far is it?  In any case a subpanel is almost as easy to wire as a breaker.


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## John_Dennis (Mar 8, 2014)

mrbreezeet1 said:


> sorry if this was covered, but is it too far to run a new wire for a 220 V outlet from the Breaker, Or a Sub panel?
> A 220 v breaker/outlet is not hard to wire at all.
> Again, sorry if this was covered.
> Thanks,
> Tony




There is no such thing as too far.  The rule is, I believe, if the  distance (actual conductor length) is more than 120 feet, then you have  to increase the conductor by 1 size. This will not matter in a  residential home because the distance will be very short.  Just decide  what the largest machine you will need to run in your shop will be,  probably a welder, and then run a circuit that will accommodate that.   If you are willing to invest in the wire, put a 50 or 70 amp sub panel  in the garage. This will make it easy to add extra plugs or reset the  breaker.  The amperage capacity of a circuit is determined bu the wire size. If the wire is too small it will get hot and can even start a fire.  Too small of a conductor will also cause voltage drop. If you use too small of an extension cord, for instance, you can burn up a motor. Lower voltage = more heat in a motor.

By the way while 220 is not technically 2 phase, the  concept is the same. European 240v is similar to US 277v which is high  voltage and much more dangerous that 110. 1 leg 240 not 2 legs of 120.

I believe that a 2 hp motor on 120 will take 25 amps, that is why you almost never see one, since 120 plugs are usually 15 or 20 amps. To run a 2hp motor with some kind of transformer, if one even exist, you would need a 30 amp 110 circuit.  

I think to get 2 legs of 120 from 1- 120 circuit you would need a very complicated device similar to a digital phase converter. In any case this route will be either expensive, disappointing or both.

In Texas, most modern homes with gas appliances have connections for both a gas and electric clothes dryer. You could tap into this circuit and add a plug in the garage if your dryer is gas.

Just bite the bullet and run yourself a nice beefy circuit to your garage. You will be happier in the long run.


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## John Hasler (Mar 8, 2014)

John_Dennis writes: 





> I think to get 2 legs of 120 from 1- 120 circuit you would need a very  complicated device similar to a digital phase converter. In any case  this route will be either expensive, disappointing or both.



An autotransformer would do it, as would a step-up transformer with a center tap.  Better to just run a feeder and put in a subpanel, though.  You can have up to six breakers in a subpanel without needing a main breaker.


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## k1pyp (Mar 8, 2014)

mrbreezeet1 said:


> sorry if this was covered, but is it too far to run a new wire for a 220 V outlet from the Breaker, Or a Sub panel?
> A 220 v breaker/outlet is not hard to wire at all.
> Again, sorry if this was covered.
> Thanks,
> Tony



I will run a 220 v line if the need arises. I was trying to see if an inexpensive voltage converter will work w/o having to add a 220 volt line.  Adding a new line is probably not difficult but if I decide to do it, I plan to use a licensed electrician and get proper permits to maintain a resale value of my house.


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## John Hasler (Mar 8, 2014)

k1pyp said:


> I will run a 220 v line if the need arises. I was trying to see if an inexpensive voltage converter will work w/o having to add a 220 volt line.  Adding a new line is probably not difficult but if I decide to do it, I plan to use a licensed electrician and get proper permits to maintain a resale value of my house.



What repressive jurisdiction do you live in that requires permits and licenses for something that trivial?  In any case it should only enhance the value of your property if you do it right.  The government has no detailed record of how your house was wired.


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## k1pyp (Mar 8, 2014)

John Hasler said:


> What repressive jurisdiction do you live in that requires permits and licenses for something that trivial?  In any case it should only enhance the value of your property if you do it right.  The government has no detailed record of how your house was wired.



The entire state of California seems like that.  I have given some thoughts to moving out of state someday.

Although I am disappointed that a simple voltage converter will not work, I actually learned a lot from this thread. Tthanks everyone from responding to my questions.

Paul


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