220 Volt Question

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.
 
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.
 
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

 
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.
 
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.
 
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.
 
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.
 
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.
 
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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