Why 60 volt on a 240 volt circuit?

Wiring 220 circuit in my garage I have one circuit with 4 outlets that only registers 60 volts. The others I wired register 240. Ideas why?
Thanks.
Trent
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A reason that comes to mind is that the miscreant circuit has the outlets wired in series. They should be wired in parallel.
Jim

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First idea that comes to mind is that the circuit is not powered on, and you're using a digital meter -- and measuring a microampere current that's induced in the line by current in an adjacent circuit. Connect a load of some sort to the circuit, and see what happens to the voltage then. I'm betting it drops to zero.
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Regards,
Doug Miller (alphageek at milmac dot com)
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When I check my other outlets, on another circuit, they read 240 with a digital meter. It is just these 4 that register 60 on each one.
Previous post said they may be wired in series, how would that happen?
On Sat, 03 Nov 2007 00:53:42 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

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Turn off the power and take the outlets out of the box. Examine the wiring and make a note of how its wired. The only way I can think to have the outlets wired in series would require something to be plugged in to each one to complete the circuit. (I.E. When one bulb goes, all the lights go out.)
Should the outlets successfully been wired in series, I'd love to find out how that was accomplished! It's almost planned stupidity.
Puckdropper
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Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm
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wrote:

As Doug mentioned...
Does your meter "auto range"? You might be reading a very tiny, as in microvolts, induced voltage.
--------------------------------------------- ** http://www.bburke.com/woodworking.html ** ---------------------------------------------
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wrote:

An induced voltage doesnt have to be tiny. 60V is well within range of an induced voltage on an open wire with a high impedence meter.
You have an open wire somewhere up line from where you're measuring, as others have said.
Take a lamp and plug it into one of the dead outlets, turn it on and the voltage reading should drop to zero.
-dickm
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Ok.. I know I'm not an electrician, but are their 220/240v lamps?
mac
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That's not the point. The point is that supplying a continuity with a relatively low resistance should drop the voltage to zero. That would eliminate the "induced voltage that you saw. If you wired things somehow in series, the bulb would (on that 60 V) probably glow only faintly if at all.
If you put a lightbulb that is designed for 110V in a 220V circuit I assume it will burn, maybe brightly for only a short period of time. I think R is constant R=I/V, so maybe I will be half if V is twice, maybe not.
In Europe almost all bulbs will be 220/240V. I know that even with a transformer, our Dutch 220V sewing machine would not run on 110V. I can't check it anymore, since someone stole it.
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Best regards
Han
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Han wrote:

American 220/240 volt is twin phase (two hot wires) in the EU its single phase (0ne hot wire) thats why the equipment is not interchangeable
In the UK both the Earth and neutral go to ground (neutral at the substation , earth eithr at the sub or copper point in the ground )
Our 110 Volt systems are used only on construction sites from a centre tpped transformer so you only get a 55 volt shock if you ground yourself out
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I was so naive as to think that inputting 110 V to a transformer with a220V out put would be able to power a sewing machine. It didn't. Why, I don't know - not enough amps to go through the transformer? 50 vs 60 Hz? But spouse got a made for (or in) US sewing machine and did make nice quilts and other things <grin>.
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Best regards
Han
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steve robinson wrote:

nope, not in the USA that I live in.... We have single phase, center tapped 240 volt supplied to residential areas. This is not "twin phase" at all, it is just the output of a center tapped transformer. The center tap is considered "neutral" and is grounded in most areas, so the individual legs of the service supply 110 volts relative to ground, and the voltage across the two legs are 240 volts. Commercial service is quite different, though can supply 110 volts in some configurations.
There is no place coming from commercial mains that you're likely to find a split 110 volt supply even at construction sites. All construction sites are supplied the same 240 volt center tapped service as the building will have when it is done. Assuming otherwise can get you in serious trouble....
I don't know if one leg of Euro 220 volt power is grounded or not, but the big difference that causes people problems with trying to run Euro motor based appliances in the US is the US is on 60hz and Euro is 50hz. For some things (transformers, etc.) this is typically a relatively minor issue, with only minor heating effects and increased losses, as long as they are lightly loaded. On the other hand, the shorter cycle time between 60hz compared to 50hz causes starting problems for some motors, in that they won't start unassisted, and will run faster and sometimes hot enough to destrly themselves if you do get the Euro motor running on US current. I would imagine a sewing machine might have other issues, as it is a variable speed motor to begin with, and the issue may have been more of one with the controller than the actual motor.
The original poster that suggested the circuit is open somewhere and you are measuring induces voltage was probably correct. You need to put some sort of load on the circuit to see for sure. if it's a 240 volt outlet, you will find out immediately if you really have induced voltage if you connect a bulb across the circuit. If it's open the bulb will be dark and you can measure 0 volts, and if it were actually 240 volts and the meter lied, the bulb will burn out quite dramatically within a second or so.
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Haven't read the posts following this one, but I'd like to point out that Ohm's Law is V=IR so that R=V/I and I = V/R so it follows that with a constant R, double the voltage means double, not half, the amperage. The equation for Power, P=IV, does imply that for a constant power, double the voltage implies half the amperage.
Tom Veatch Wichita, KS USA
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Tom Veatch wrote in wrote:

You're so right. I hope my kids don't read this <shamed>
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Best regards
Han
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I'd like to get a supply of those European light bulbs.
I've set all the machines that support conversion to run on 220V. Which means that the built-in work light on my drill press sees 220V unless I rewire the tool, adding a neutral conductor and replace the NEMA 6-15 plug and receptacle with a NEMA 14-15 configuration (the circuit is already wired as a 120/240 3+ground circuit). Or I could do as the owner's manual recommends, which I won't repeat here since it violates holy hell out of every electrical code I've ever heard of.
(I found some 220v light bulbs at Grainger, but they won't fit the cavity in the body of the drill press)
Tom Veatch Wichita, KS USA
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Tom Veatch wrote:

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Thanks, dpb, I've ordered a couple of those.
I hope they mean it where they say "_regular size_ light bulbs like you use in your home". The ones from Grainger are slightly larger diameter than the "regular size".
Tom Veatch Wichita, KS USA
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Tom Veatch wrote:

I didn't check the base/configuration data specifically, but should be available.
Don't you have a neutral in the cordset, though? All seems would need to do is to tap off the one hot side for the light.
Otherwise, probably simplest to just put a replacement line cord on the tool, I'd think.
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The existing cordset only has two conductors plus ground. But to get both 120 and 240 to the tool, 3 conductors plus ground are required - 2 "hot" wires for the two legs of the 240v, and 1 "neutral" for the 120v, plus, of course, the equipment grounding wire.
A new 4 wire cordset (plus plug and receptacle replacement) would fix the supply problem and is probably the best long term solution assuming the DP won't ever be converted back to 120v. But, a new 4 wire cordset also means the tool needs to be rewired (or the existing internal wiring at least has to be reconfigured) to get the two hots to the motor and one of the hots plus neutral to the worklight fixture. I haven't opened it up to see, so it might not be any big deal, but 220v light bulbs, if they fit, is a very simple solution.
And, of course, a completely separate task light clamped to the DP column is always a "that's good enough" option.
Tom Veatch Wichita, KS USA
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Tom Veatch wrote:

...
Call me old, but we ran split voltage appliances on 3-wire for a long time...
But, unless it's a heck of a press, seems hardly worth even the extra hassle of the special-order light bulb to me..
That, of course, is just me...
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