220V dryer sparked on startup (3 wire) What to test?

[Danny D'Amico]

The wife said the dryer was sparking "in the back".
I moved things around, but didn't see anything so I tell the wife not to worry.

A week later, I turn on the 220v 3-wire dryer, and a single bright white spark
snaps in the back, between the dryer and the 4-foot 6-inch diameter aluminum
corrugated lint pipe connect to the outside vent.

Huh?

Could it be static electricity?
Could it be the dryer frame is hot?
What do I test?

The only connection to the wall is the three-pronged 220v dryer cord, which
looks perfectly fine when I remove it from the wall outlet.

There is no specific "ground" wire from the dryer to anything (should I have
put a ground wire in to the 120 volt outlet nearby?).

What would you test?
If you need pictures, just ask.

[Stormin Mormon]

My gut sense, is that something is loose inside
the dryer. Something (sounds like) is touching
the case of the dryer, and charging it.

I'd pull the plug, check for continuity between
power and ground prongs of the plug. I'd also
open up the case, and look for bare, burnt,
or loose wires.

Do you have any friends with electrical skills?

--
.
Christopher A. Young
Learn about Jesus
www.lds.org
.

[Ralph Mowery]

"Danny D'Amico" <dan...@is.invalid> wrote in message
news:l63cn1$9uq$1...@speranza.aioe.org...

It could be static electricity. Is the 4 foot long vent pipe seperated from
the dryer by some material that does not conduct electricity ? If so you
may want to connect a wire between the pipe and dryer. It does not have to
be very large as almost no curent is going through it, just high voltage.

You may also want to look at the dryer where the power wire is. As this is
only a 3 wire cord make sure there is a strapgoing from the neutral wire to
the frame of the dryer. This should be factory installed so it can be used
for 3 wires or bent out of the way if a 4 wire cable is used.

While it may not trip a breaker, I would think it might if there was an
intermittant short in the power wiring.

[Tony Hwang]

Hi,
What is your multi-meter doing? How about measuring things between vent
pipe and dryer body for a starter? 220V can kill.....

[Danny D'Amico]

On Thu, 14 Nov 2013 15:55:24 -0500, Stormin Mormon wrote:

> I'd pull the plug, check for continuity between
> power and ground prongs of the plug. I'd also
> open up the case, and look for bare, burnt,
> or loose wires.

This is the 3-pronged 220 volt cord connected to this dryer:
http://farm6.staticflickr.com/5495/10862520585_e4a63d0028_o.gif

I think, IIRC, two of the prongs are 120 volt hot wires, 120 degrees
out of phase (that's the 220 volts); while the third, I think, is a
neutral wire.

So, I think, IIRC, the 120V circuitry in the dryer (e.g., the light
bulb and the controls and perhaps even the motor) run off one of
the hot wires and the neutral; while the heater runs off the full
220 volts from the two hot wires and the neutral.

So, there is no ground that I know of, if I understood this correctly.
That's why I asked if you guys ADD a ground wire in this situation?
http://farm4.staticflickr.com/3753/10862565466_e2473a60a8_o.gif

[Danny D'Amico]

On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote:

> It could be static electricity. Is the 4 foot long vent pipe seperated from
> the dryer by some material that does not conduct electricity ?

I'm not sure HOW static electricity could build up, but, that's the only
thing, at the moment, that makes sense to me.

Here's a picture of what the vent hose looks like when it's all in place:
http://farm4.staticflickr.com/3815/10862854513_17c2fe362f_o.gif

Here's a front view:
http://farm4.staticflickr.com/3833/10862855523_8f2c472367_o.gif

[Danny D'Amico]

On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote:

> You may also want to look at the dryer where the power wire is. As this is

> only a 3 wire cord make sure there is a strap going from the neutral wire to

> the frame of the dryer. This should be factory installed so it can be used
> for 3 wires or bent out of the way if a 4 wire cable is used.

Hmmm... There is no *external* 'strap" going to the steel frame of the dryer.
Are you saying there should be an *internal* strap that I can look for?
http://farm4.staticflickr.com/3812/10862854943_3bf128caf4_o.gif

[dpb]

On 11/14/2013 7:25 PM, Danny D'Amico wrote:
...

> So, there is no ground that I know of, if I understood this correctly.

...

No, you misunderstood (or the reference you looked at was wrong; I
didn't check it) -- the third wire is the ground but NEC until
relatively recently allowed the ground to also be the neutral in
specific instances, the household dryer likely the most prevalent
followed closely by electric range.

The "blinding flash" _may_ have been one of the two heater coils failing
-- does the dryer still reach full temp and otherwise function properly
as far as you can tell? If it's now taking a lot longer for things to
dry, likely you did lose an element.

If, as somebody else noted, it didn't trip the breaker the likelihood of
a short other than the element is minute. In 60 yrs in a dry climate
I've never seen a static electricity flash from a dryer vent or even got
a shock so don't say it's not possible but surely sounds far-fetched
hypothesis to me.

OTOH, when wife sewed a lot or when were many cloth diapers so that
straight or safety pins accidentally getting in the dryer caused fair
number of element shorts when one would finally manage to get thru the
vent holes in the rear of the drum and land across a heater coil. Or,
they do eventually fail on their own...

--

[Ralph Mowery]

"Danny D'Amico" <dan...@is.invalid> wrote in message

news:l63tdc$f0i$3...@speranza.aioe.org...

This looks like a 3 wire power cord. You need to unplug the dryer and open
up the back where the wire goes in. Look and there will be 3 terminals the
power wire hooks to. It will probably be the middle wire that is the
neutral and there should be a strap going from there to the frame of the
dryer.

While the dryer is open look around for any black or burnt areas near wires
or the internal electrical parts.

[Danny D'Amico]

On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote:

> the third wire is the ground but NEC until
> relatively recently allowed the ground to also be the neutral

You seem to understand this better than I do.

The way *I* understand a "ground" is that a ground wire carries no current
(unless there is a problem). The "neutral" wire, on the other hand, *always*
carries current.

That's a pretty big difference (as I understand it anyway).

More specifically, the way I understand a ground wire, is that it goes
from the receptacle in the wall to the main breaker panel, where it
literally is driven directly into the ground (usually by some kind of bar).

In contrast, the neutral wire, as I understand it, goes to the same
breaker panel, but then it goes from there to the power pole, and then
from that pole it may travel hundreds of feet to a few more power poles,
but eventually, it too is driven straight into the ground.

The difference, as I understand it, is that the ground never carries
current (unless there is a fault), while the neutral is always carrying
current (and therefore it might have a potential on it).

Given that they're not at all the same thing, I then have trouble
understanding the statement that the ground is "also" a neutral.

Again, you seem to understand better than I do, but, the way I
described it above, a ground and a neutral are totally different
things.

So, I don't understand how a ground can 'also' be a neutral.

[Danny D'Amico]

On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote:

> The "blinding flash" _may_ have been one of the two heater coils failing
> -- does the dryer still reach full temp and otherwise function properly
> as far as you can tell? If it's now taking a lot longer for things to
> dry, likely you did lose an element.

As far as I know, the dryer works just fine.

My wife said it was making static sounds in the back, when she turned it on
about a week ago, which I had dismissed until I saw the bright spark at the
aluminum vent hose when I turned it on.

The spark happened quickly, so, I'm not exactly sure *where* it was, but, it
was *OUTSIDE* the dryer.

The white spark *appeared* to be between the dryer frame and the
aluminum vent hose, as shown in this picture in a RED mark:
http://farm6.staticflickr.com/5494/10862933275_e49cd016bd_o.png

[Danny D'Amico]

On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote:

> If, as somebody else noted, it didn't trip the breaker the likelihood of
> a short other than the element is minute. In 60 yrs in a dry climate
> I've never seen a static electricity flash from a dryer vent or even got
> a shock so don't say it's not possible but surely sounds far-fetched
> hypothesis to me.

This is good to know, since the static electricity idea was the only
one I could come up with that was benign.

I would agree that static electricity isn't likely, so, let's forget
about that.

But, if it's not something benign, then I need to figure out WHAT is
making that spark, and why.

The whole fact that there is no explicit ground is part of what confuses
me.

I'll check to see if the body of the dryer is hot with respect to ground.

[Danny D'Amico]

On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote:

> While it may not trip a breaker, I would think it might if there was an
> intermittant short in the power wiring.

Just to confirm, there is a breaker in the laundry room and it has not
tripped.

So, whatever it is, it isn't pulling enough current for a long enough time
to overheat the breaker switch.

[Ralph Mowery]

"Danny D'Amico" <dan...@is.invalid> wrote in message

news:l63uu2$hnf$3...@speranza.aioe.org...

The power comes into your house by 3 wires. At the pole is a transformer
that has a wire on each end of a coil and one from the center. If you only
used 240 volt devices there would be no need for the neutral wire. If the
power usage on each side of the 120 volt lines were exectally the same there
would not be any need for the neutral going to the pole. As the sides are
not exectally ballanced and often not ballanced very well at all, the
neutral carries the unballanced current. In the house the 120 volt circuits
use one of the hot wires and the neutral for the return.

At your breaker box the neutral is bolted to the frame of the box and it
also goes to the recepticls and other parts of the house. The ground wire
goes to a rod outside the house that is driven into the ground. It is
bolted to the frame of the breaker box. It then also goes whever the power
wires goes to such as the recepticals. In effect the neutral and ground
wire are the same wire, but perform differant functions. Often the neutral
or ground wire may be a differant size than the two hot 240 volt wires. If
the neutral and ground wires are the same size, there is no electrical
reason that you could not use either of them for the ground or neutral. YOu
do not want to do this as it can create great confusion to the people doing
the wiring. That is one reason the neutral is insulated and white and the
ground is either bare or green.

The two hot wires may be red and black or maybe just two black wires as it
does not usually mater which wire is hooked to which side of the 240 volt
device.

YOu are correct, there should not be any current on the ground wire unless
there is a problem. If one of the hot wires shorts to the frame of the
dryer and there is no ground or neutral (on a 3 wire plug) connected to the
frame, it becomes 120 volts to ground and if you or anything conductive gets
between the frame and the real ground or another device that has its frame
grounded, there will be current flowing and could shock or kill.


If in the 3 wire circuit the neutral becomes disconnected down line of the
dryer, the frame of the dryer will become hot with 120 volts minus a small
ammount. That small ammount could be the timmer and light bulb in the dryer
that is still connected to one side of the 240 volt line.
That is the reason for using the 4th wire that is only connected to the
frame of the dryer in later years.

[Stormin Mormon]

You're out of your field of training, here, my friend. I'd suggest you
find someone you can trust, who knows some about electricity.

Two hots, and a ground. No neutral wire.

[Stormin Mormon]

Please be careful listening to this person. Three
wire dryer connection has two hots and a ground.
No neutral. And, you'd never deliberately connect
a neutral to the frame or case.

[Stormin Mormon]

On 11/14/2013 8:39 PM, Ralph Mowery wrote:
> This looks like a 3 wire power cord. You need to unplug the dryer and open
> up the back where the wire goes in. Look and there will be 3 terminals the
> power wire hooks to. It will probably be the middle wire that is the
> neutral and there should be a strap going from there to the frame of the
> dryer.
>
> While the dryer is open look around for any black or burnt areas near wires
> or the internal electrical parts.

Three wire cord doesn't have a neutral.
Two hots and a ground.

[Stormin Mormon]

On 11/14/2013 8:55 PM, Danny D'Amico wrote:
>
> So, I don't understand how a ground can 'also' be a neutral.
>

Both go to the Earth. Small loads like a timer,
can flow a small enough current, that it doesn't
noticeably raise the electrical potential of the
ground line.

[WW]

"Tony Hwang" wrote in message news:C1chu.343580$Oj5....@fx02.iad...

Tony,,, You can only get the one leg of voltage to ground on a 220 volt
system on a dryer. However that also is dangerous. The OP may have a sagging
heater coil that is touching the case. If he is not handy on this stuff,
time to get an appliance repairman to check and repair it. WW

[Ralph Mowery]

"Stormin Mormon" <cayo...@hotmail.com> wrote in message
news:ZRfhu.229914$dn7.2...@fx20.iad...

> Please be careful listening to this person. Three
> wire dryer connection has two hots and a ground.
> No neutral. And, you'd never deliberately connect
> a neutral to the frame or case.
>

Hate to inform you, but in a 3 wire dryer socket there are 2 hots and a
neutral. There is no ground.
Go here and learn.
http://www.how-to-wire-it.com/wire-a-dryer-cord.html

Also notice the picture where the frame of the dryer is attached to the
neutral wire.

[Nightcrawler®]

"Stormin Mormon" <cayo...@hotmail.com> wrote in message news:NSfhu.129679$bQ1....@fx10.iad...

Wrong! Two hots and a grounded conductor (neutral/white). These types of
plugs are often referred as a 120/240. Meaning that it provides both voltages
to the device. The new 4-wire plugs do the same thing, but have a dedicated
grounding conductor for fault purposes.

As per code, a grounding conductor shall "never" carry any current unless
a fault is present; and the only purpose for carrying this current is to
trip the breaker. The other purpose of a grounding conductor is to equalize
the potential of attached devices to ground, thereby reducing, but not eliminating,
the risk of shock.

(it is possible that the service is 110/220)

[Nightcrawler®]

"Danny D'Amico" <dan...@is.invalid> wrote in message news:l63uu2$hnf$3...@speranza.aioe.org...

> On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote:
>
>> the third wire is the ground but NEC until
>> relatively recently allowed the ground to also be the neutral
>
> You seem to understand this better than I do.
>
> The way *I* understand a "ground" is that a ground wire carries no current
> (unless there is a problem). The "neutral" wire, on the other hand, *always*
> carries current.

You are correct. In old installations range and dryer outlets only had three
wires, and it was allowed to use the "neutral" as a ground fault path.

[Stormin Mormon]

Well, golly gee!
http://www.ezdiyelectricity.com/?p=221

http://electrical.about.com/od/appliances/ss/4prongto3prongdryercordss_4.htm

It sure seemed counter intuitive that the third prong would be neutral,
and the device is ungrounded. But, I found a couple web sites that say
it is. And says that it bonds the neutral to the frame. Go figure.

Well, thanks for showing me some thing new. I
find myself with egg on my face.

http://fc03.deviantart.net/fs71/i/2012/166/4/8/egg_on_your_face_by_gailweiss-d536n7e.jpg

Good thing I've been recently instructed how to apologize.

http://youqueen.com/wp-content/uploads/2012/09/How-to-Apologize.jpg

[Wes Groleau]

On 11-14-2013, 20:27, Danny D'Amico wrote:
> On Thu, 14 Nov 2013 16:47:47 -0500, Ralph Mowery wrote:
>> It could be static electricity. Is the 4 foot long vent pipe seperated from
>> the dryer by some material that does not conduct electricity ?
>
> I'm not sure HOW static electricity could build up, but, that's the only
> thing, at the moment, that makes sense to me.

If it only happens when you turn it on, it wouldn't be static build up.
That would have dissipated while it was off.

I'm wondering about some kind of misalignment or wearing out in a
two-pole switch. If one side of the 240 is energized ten milliseconds
before the other, AND that side is shorted to the shell, AND the shell
is not grounded but the vent hose _is_, then this could happen.

And that would be dangerous, obviously. Call a pro. Happy Halloween.

--
Wes Groleau

“Brigham Young agrees to confine himself to one woman,
if every member of Congress will do the same.”
— Weekly Republican, 1869

[Ralph Mowery]

"Stormin Mormon" <cayo...@hotmail.com> wrote in message

news:Nsohu.32667$8O5...@fx04.iad...

> It sure seemed counter intuitive that the third prong would be neutral,
> and the device is ungrounded. But, I found a couple web sites that say it
> is. And says that it bonds the neutral to the frame. Go figure.
>

For common house circits there is no real electrical differance in the
neutral and ground wires. They both start at the same point in the breaker
panel and run parallel with each other to the socket or device that they are
connected to.
.
Mechanically there is often a differance. The ground will either be bare or
green and the neutral will be white by the electrical code. They may even
be differant sizes.

When used in the 240 volt circuits the 4 th wire ground is just a redundant
wire that is connected to the frame of the device . This is an added safety
precaution incase for some reason the neutral wire would become disconnected
if only a 3 wire circuit was used.

[Danny D.]

On Thu, 14 Nov 2013 21:40:25 -0500, Stormin Mormon wrote:

> Two hots, and a ground. No neutral wire.

I may well be out of my league, but, I've wired 220 in
the past, and, well, *I* used two black and one white
(i.e., two hots and a neutral), and it worked, for me.

My problem at that time was that the wiring was in an
old house with screw-in fuses, so, that arrangement
above would tend to blow one fuse but not the other,
which wasn't really a good idea.

I could tell a fuse had blown 'cuz the motor would
hum instead of move for the compressor. But, when I
replaced the fuse, it would work again.

Dumb. Yes. I agree. Darwin award even? Perhaps.
But, clearly, *my* 220 in that case was two hots and
a neutral.

I supposed had I two hots and a ground wire tied to
the cold water pipe, it would have worked as well.

And, I must note, that I've *followed* the neutral
wire, in the olden days, when wires were above ground,
from the house, to the pole, to the next pole, to the
next (as far as I could tell anyway), until it went
straight into the ground.

Of course, I really didn't follow the wire directly,
but, I surmised the neutral went into the ground at
every third pole. At least that's what I remember
surmising way back when ...

So, *both* a ground and a neutral go into the ground.
The only difference, as I see it, is that the neutral
goes into the ground hundreds of feet away, and it
carries current; while the ground goes into the ground
at the edge of the house, and, it's not carrying current
(unless there is a fault).

So, given all that, I think we're talking semantics here.

I have two hots and this "thing" which goes into the
ground a few hundred yards from the house.

Apparently this "thing" is acting both as a ground, and
as a neutral. I'm going to check that this "thing" is
actually *connected* to the steel case of the dryer and
report back!

Thanks!

[Danny D.]

On Fri, 15 Nov 2013 22:14:25 +0000, Danny D. wrote:

> I have two hots and this "thing" which goes into the
> ground a few hundred yards from the house.

By the way, the reason (I think) I know that this 'thing'
is a neutral (and not a ground) is that it *must* be
carrying current.

If the two hots were out of phase by 180 degrees, then
we wouldn't need this third 'thing'.

But, three wire distribution along the poles is such that
the hot wires are only 120 degrees out of phase (IIRC).

So, if I'm correct, my two hots are 120 degrees out of phase,
which means current *must* be going somewhere. That somewhere
is this third 'thing'.

Since this third 'thing' is designed to carry current, it's
clearly not a ground (since a ground isn't designed to carry
current normally).

Now, again, the fact that this third 'thing' goes into the
ground makes it 'look' like a ground (to some); but it *must*
be carrying current; so, semantically, I wouldn't call it a
ground.

Still - I must profess ... this is only how *I* understand the
situation; and I may well be wrong (although I think it's this way).

So, I will try to explain what you guys are trying to tell me
in the next post (this is too long already).

[Danny D.]

On Fri, 15 Nov 2013 22:21:18 +0000, Danny D. wrote:

> So, I will try to explain what you guys are trying to tell me
> in the next post (this is too long already).

I think you guys are trying to tell me that this third 'thing'
goes from the wall to the dryer innards.

At the same time, it goes to the dryer steel frame!

So, if one of the hot wires were to touch the steel frame,
it would go into this third 'thing' and it would go back to
the wall.

And, from the wall, it would go to the breaker box; and from
the breaker box to the power pole; and from the power pole
to another, and finally, a pole or three away, it would go
into the ground.

Back at the dryer, that would mean that the steel case of
the dryer is attached to the ground by a long wire of a
few hundred feet or more.

So, the steel case *could* have a potential on it!
(which would be the difference in voltage between the hot
wire and the ground a few hundred feet away).

[k...@attt.bizz]

On Fri, 15 Nov 2013 01:25:56 +0000 (UTC), Danny D'Amico
<dan...@is.invalid> wrote:

>On Thu, 14 Nov 2013 15:55:24 -0500, Stormin Mormon wrote:
>
>> I'd pull the plug, check for continuity between
>> power and ground prongs of the plug. I'd also
>> open up the case, and look for bare, burnt,
>> or loose wires.
>
>This is the 3-pronged 220 volt cord connected to this dryer:
> http://farm6.staticflickr.com/5495/10862520585_e4a63d0028_o.gif
>
>I think, IIRC, two of the prongs are 120 volt hot wires, 120 degrees
>out of phase (that's the 220 volts); while the third, I think, is a
>neutral wire.

180 degrees, but technically, no. It's opposite sign, not 180 degrees
out of phase. ...and it should be 240V (twice 120V).

>So, I think, IIRC, the 120V circuitry in the dryer (e.g., the light
>bulb and the controls and perhaps even the motor) run off one of
>the hot wires and the neutral; while the heater runs off the full
>220 volts from the two hot wires and the neutral.

The timer usually runs off 120V.

>So, there is no ground that I know of, if I understood this correctly.
>That's why I asked if you guys ADD a ground wire in this situation?
> http://farm4.staticflickr.com/3753/10862565466_e2473a60a8_o.gif

The ground is a must, for safety. At one time, it was allowed to run
the timer current though ground. A neutral conductor is now required
for that current.

[Danny D'Amico]

On Thu, 14 Nov 2013 15:21:16 -0700, Tony Hwang wrote:

> What is your multi-meter doing? How about measuring things between vent
> pipe and dryer body for a starter? 220V can kill.....

Nothing is hot. At least now.

[Danny D'Amico]

On Thu, 14 Nov 2013 19:50:13 -0700, WW wrote:

> The OP may have a sagging heater coil that is touching the case.

That's interesting. I never saw a heater coil, let alone a sagging
heater coil.

Googling for images, I see these:
http://www.partsdr.com/Parts/279838-heating-element-assembly-119.cfm?Partner=Forum279838
http://www.rcappliancepartsimages.com/dbImages/00000077/00021876.jpg

I'll have to look deeper...

[Danny D'Amico]

On Thu, 14 Nov 2013 20:39:41 -0500, Ralph Mowery wrote:

> While the dryer is open look around for any black or burnt areas near wires
> or the internal electrical parts.

Does this look ok from where you sit?
http://farm6.staticflickr.com/5474/10879027305_17cb94ac7e_o.gif

[Danny D'Amico]

On Thu, 14 Nov 2013 21:42:54 -0500, Stormin Mormon wrote:

> Three wire cord doesn't have a neutral.
> Two hots and a ground.

There is a bolt for an external ground here:
http://farm6.staticflickr.com/5474/10879027305_17cb94ac7e_o.gif

[Danny D'Amico]

On Thu, 14 Nov 2013 23:00:26 -0500, Ralph Mowery wrote:

> Go here and learn.
> http://www.how-to-wire-it.com/wire-a-dryer-cord.html

Thank you so much for finding that reference for us!
I was getting confused, by the conflicting information.
This is what my wires look like at the dryer:
http://farm4.staticflickr.com/3670/10879404993_905821a83c_o.gif

I'll need to go back there and doublecheck that the white wire
that is connected to the frame is also connected to that middle
(white) wire (neutral?) which is surrounded by two black wires (hot).

[mako...@yahoo.com]

to the op
caution, this may be dangerous
you have read that the 3 prong setup shares the ground and the neutral.
so if this shared ground neutral should have a loose wire, this could cause the dryer frame to become energized.
and perhaps the metal vent pipe is completing the circuit to ground. that may be why you hear and see sparks.
i would not use this appliance again until this is fixed

if you feel you can handle this, do what you suggested, run a heavy wire from the dryer frame to a nearby outlet ground.

after you add a ground , this should make it relatively safe, but get someone to check it before you get shocked or start a fire.

Mark

[Ralph Mowery]

"Danny D'Amico" <dan...@is.invalid> wrote in message
news:l66nsp$90f$1...@speranza.aioe.org...

I don't see any provision for a strap from the dryer frame to the center
neutral connection for that particular dryer. It would be good to know where
that white wire that is under the ground screw comes from.

I have not seen it, but can you give the make and model of the dryer so I
can look for a wiring diagram for it ? If you have the book for it, it may
have the diagram in it for a 4 and 3 wire hookup.

As someone else said, I would run a wire from the dryer to a ground
somewhere.

[Nightcrawler®]

"Danny D'Amico" <dan...@is.invalid> wrote in message news:l66ndr$7g1$3...@speranza.aioe.org...

That green wire needs to be terminated on the center terminal.
This will bond the dryer to ground (yes, the neutral). If there
is a short you will find out pretty quick.

[Nightcrawler®]

"Nightcrawler®" <dirty...@dirtcheap.org> wrote in message news:l6701r$8vk$1...@dont-email.me...

I could not tell what the other end of that wire is doing, and
assumed that it was not terminated. If, by chance, it is affixed
someplace else, make a jumper wire that will go under that screw
and terminate it on the center terminal.

[Nightcrawler®]

"Danny D." <dan...@nowhere.com> wrote in message news:l66711$5ei$1...@speranza.aioe.org...

I have a simple question that might clear some things up. The
two hot wires, are they wrapped around a bare cable that is
secured at the house and the power pole?

[Wes Groleau]

On 11-15-2013, 19:58, k...@attt.bizz wrote:
> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
> out of phase.

Same thing


--
Wes Groleau

He that is good for making excuses, is seldom good for anything else.
— Benjamin Franklin

[Stormin Mormon]

On 11/15/2013 7:58 PM, k...@attt.bizz wrote:
>
>> So, there is no ground that I know of, if I understood this correctly.
>> That's why I asked if you guys ADD a ground wire in this situation?
>> http://farm4.staticflickr.com/3753/10862565466_e2473a60a8_o.gif
>
> The ground is a must, for safety. At one time, it was allowed to run
> the timer current though ground. A neutral conductor is now required
> for that current.
>

I've been trying to figure if the cold wire of a
three wire dryer is a neutral or ground. I'd thought
it was a ground, but some folks on the list and
on the web thought it's a neutral.

[Stormin Mormon]

Looks fine, on my web browser.

[Stormin Mormon]

It may or may not be to code, but I'd sure want to
put an external ground on my drier, if it sparked.

[k...@attt.bizz]

On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
<Grolea...@FreeShell.org> wrote:

>On 11-15-2013, 19:58, k...@attt.bizz wrote:
>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>> out of phase.
>
>Same thing

No, it's not. It's one phase.

[k...@attt.bizz]

It *is* a ground. It's connected to the case of the appliance. Would
you connect a neutral to the case?

[k...@attt.bizz]

It's also connected to the ground bus inside the box, not the neutral
bus. Uninsulated, too.

[Stormin Mormon]

On 11/16/2013 11:35 AM, k...@attt.bizz wrote:
> On Sat, 16 Nov 2013 06:31:21 -0500, Stormin Mormon

>> I've been trying to figure if the cold wire of a
>> three wire dryer is a neutral or ground. I'd thought
>> it was a ground, but some folks on the list and
>> on the web thought it's a neutral.
>
> It *is* a ground. It's connected to the case of the appliance. Would
> you connect a neutral to the case?
>

Oh, now I'm all confused.

[Tony Hwang]

Hi,
It's called bi-phase. aka Edison circuit.

[Ralph Mowery]

"Stormin Mormon" <cayo...@hotmail.com> wrote in message

news:WhNhu.186029$DT4....@fx13.iad...

> On 11/16/2013 11:35 AM, k...@attt.bizz wrote:
>> On Sat, 16 Nov 2013 06:31:21 -0500, Stormin Mormon
>>> I've been trying to figure if the cold wire of a
>>> three wire dryer is a neutral or ground. I'd thought
>>> it was a ground, but some folks on the list and
>>> on the web thought it's a neutral.
>>
>> It *is* a ground. It's connected to the case of the appliance. Would
>> you connect a neutral to the case?
>>
>
> Oh, now I'm all confused.
>

In a 3 wire dryer circuit it is acting as a neutral and as a ground.
It is more of just what you want to call it. As most dryers use the 120
volts from one leg to power the control circuits and light , the third wire
is acting as a neutral. At the same time it is connected to the frame of
the dryer and is acting as a neutral. I am sure if you search the
electrical code there will be some name for this wire.

On the 4 wire dryer wiring , you do have a seperate ground and neutral wire,
but they both connect to the frame of the breaker box so in effect it is
just one wire but they go to two differant places on the dryer. Outside the
fact they may be differant sizes and color code differantly to meet the code
it would not really mater which wire was hooked to the neutral or ground at
the dryer as they both go to the same place in the breaker box.

Having a seperate ground wire for the dryer just gives an extra layer of
protection.

[k...@attt.bizz]

On Sat, 16 Nov 2013 09:54:39 -0700, Tony Hwang <drag...@shaw.ca>
wrote:

Wrong. It's called "split-phase". ...because that's *exactly* what
it is. Two-phase is something entirely different (and quite rare).

[bud--]

The NEC previously allowed the *neutral* for ranges and dryers to also
be used as the ground. It is not allowed now for new circuits, but is
explicitly grandfathered for old circuits that were compliant when
installed.

>
> It's also connected to the ground bus inside the box, not the neutral
> bus. Uninsulated, too.

There are a number of limitations on using the neutral as both neutral
and ground. One of them is the circuit has to originate in the service
panel. The neutral and ground are bonded at the service. It has to
originate on the neutral bus. In many panels the neutral and ground bus
are the same. If there is a separate ground bus that only connected to
the enclosure the wire can not be connected there.

Another limitation is uninsulated wires in romex can not be used.

From gfretwell in a recent post:
"During WWII they jammed through an exception allowing the neutral to
also be used as the ground to save copper.
In the 1996 code cycle CMP 5 finally accepted Phil Simmon's assertion
that the war was over and they should dump this exemption for new
circuits. (existing can stay)"

[tra...@optonline.net]

On Thursday, November 14, 2013 8:55:14 PM UTC-5, Danny D'Amico wrote:
> On Thu, 14 Nov 2013 19:39:38 -0600, dpb wrote:
>
>
>
> > the third wire is the ground but NEC until
>
> > relatively recently allowed the ground to also be the neutral
>
>
>
> You seem to understand this better than I do.
>
>
>
> The way *I* understand a "ground" is that a ground wire carries no current
>
> (unless there is a problem). The "neutral" wire, on the other hand, *always*
>
> carries current.
>


That is true. But I have to be careful here. You said that the
neutral *always* carries current. I know what you mean, but there
are some here who insist on all cases being covered. So, to be
correct, it should be said the neutral carries the unbalanced
portion of the load in that 240V circuit. Whew. I hope DD
feels better now. The ground doesn't carry current unless something
is wrong.





>
> That's a pretty big difference (as I understand it anyway).
>
>

correct

>
> More specifically, the way I understand a ground wire, is that it goes
>
> from the receptacle in the wall to the main breaker panel, where it
>
> literally is driven directly into the ground (usually by some kind of bar).
>
>

Basically correct.



>
> In contrast, the neutral wire, as I understand it, goes to the same
>
> breaker panel, but then it goes from there to the power pole, and then
>
> from that pole it may travel hundreds of feet to a few more power poles,
>
> but eventually, it too is driven straight into the ground.
>
>

It's tied to the ground system of the house at the panel.



>
> The difference, as I understand it, is that the ground never carries
>
> current (unless there is a fault), while the neutral is always carrying
>
> current (and therefore it might have a potential on it).
>
>
>
> Given that they're not at all the same thing, I then have trouble
>
> understanding the statement that the ground is "also" a neutral.
>
>

It is for 3 wire appliances that were permitted to be installed
that way prior to the 90s when the code was changed. They use one
conductor for both the ground and the neutral.



>
> Again, you seem to understand better than I do, but, the way I
>
> described it above, a ground and a neutral are totally different
>
> things.
>
>
>
> So, I don't understand how a ground can 'also' be a neutral.

[tra...@optonline.net]

On Friday, November 15, 2013 5:14:25 PM UTC-5, Danny D. wrote:
> On Thu, 14 Nov 2013 21:40:25 -0500, Stormin Mormon wrote:
>
>
>
> > Two hots, and a ground. No neutral wire.
>
>
>
> I may well be out of my league, but, I've wired 220 in
>
> the past, and, well, *I* used two black and one white
>
> (i.e., two hots and a neutral), and it worked, for me.
>
>

Assuming that was prior to the mid 90s, then it was code
to use a single conductor for both the neutral and the ground.
If you did it after that, it's a code violation.




>
> My problem at that time was that the wiring was in an
>
> old house with screw-in fuses, so, that arrangement
>
> above would tend to blow one fuse but not the other,
>
> which wasn't really a good idea.
>
>
>
> I could tell a fuse had blown 'cuz the motor would
>
> hum instead of move for the compressor. But, when I
>
> replaced the fuse, it would work again.
>
>
>
> Dumb. Yes. I agree. Darwin award even? Perhaps.
>
> But, clearly, *my* 220 in that case was two hots and
>
> a neutral.
>
>

Even if it was an old house, if you were doing new
wiring, it has to comply to current code.



>
> I supposed had I two hots and a ground wire tied to
>
> the cold water pipe, it would have worked as well.
>
>
>
> And, I must note, that I've *followed* the neutral
>
> wire, in the olden days, when wires were above ground,
>
> from the house, to the pole, to the next pole, to the
>
> next (as far as I could tell anyway), until it went
>
> straight into the ground.
>
>

Hopefully it's also tied to the ground at your house panel
or else it's a major code violation.


>
> Of course, I really didn't follow the wire directly,
>
> but, I surmised the neutral went into the ground at
>
> every third pole. At least that's what I remember
>
> surmising way back when ...
>
>
>
> So, *both* a ground and a neutral go into the ground.
>
> The only difference, as I see it, is that the neutral
>
> goes into the ground hundreds of feet away, and it
>
> carries current; while the ground goes into the ground
>
> at the edge of the house, and, it's not carrying current
>
> (unless there is a fault).
>
>
>
> So, given all that, I think we're talking semantics here.
>
>

It's a more than semantics.



>
> I have two hots and this "thing" which goes into the
>
> ground a few hundred yards from the house.
>
>
>
> Apparently this "thing" is acting both as a ground, and
>
> as a neutral. I'm going to check that this "thing" is
>
> actually *connected* to the steel case of the dryer and
>
> report back!
>
>
>
> Thanks!

[bud--]

I agree it is single phase and commonly called "split phase".

I have never heard of bi-phase.

[tra...@optonline.net]

On Friday, November 15, 2013 5:21:18 PM UTC-5, Danny D. wrote:

> On Fri, 15 Nov 2013 22:14:25 +0000, Danny D. wrote:
>
>
>
> > I have two hots and this "thing" which goes into the
>
> > ground a few hundred yards from the house.
>
>
>

> By the way, the reason (I think) I know that this 'thing'
>
> is a neutral (and not a ground) is that it *must* be
>
> carrying current.
>
>
>
> If the two hots were out of phase by 180 degrees, then
>
> we wouldn't need this third 'thing'.
>
>

Wrong. The two hots are out of phase by 180.


>
> But, three wire distribution along the poles is such that
>
> the hot wires are only 120 degrees out of phase (IIRC).
>
>

Wrong. Any two of a 3 phase system are out of phase by
120. But what comes into your house originates from just
one of those via a center tap transformer.


>
> So, if I'm correct, my two hots are 120 degrees out of phase,
>
> which means current *must* be going somewhere. That somewhere
>
> is this third 'thing'.
>
>

Current from the unbalanced portion of the load flows
in the neutral. As others have pointe out, in the case of
your dryer that could be things like the timer, the light, etc.


>
> Since this third 'thing' is designed to carry current, it's
>
> clearly not a ground (since a ground isn't designed to carry
>
> current normally).
>
>

It's both.



>
> Now, again, the fact that this third 'thing' goes into the
>
> ground makes it 'look' like a ground (to some); but it *must*
>
> be carrying current; so, semantically, I wouldn't call it a
>
> ground.
>
>
>
> Still - I must profess ... this is only how *I* understand the
>
> situation; and I may well be wrong (although I think it's this way).

[tra...@optonline.net]

On Friday, November 15, 2013 7:58:24 PM UTC-5, k...@attt.bizz wrote:
> On Fri, 15 Nov 2013 01:25:56 +0000 (UTC), Danny D'Amico
>
> <dan...@is.invalid> wrote:
>
>
>
> >On Thu, 14 Nov 2013 15:55:24 -0500, Stormin Mormon wrote:
>
> >
>
> >> I'd pull the plug, check for continuity between
>
> >> power and ground prongs of the plug. I'd also
>
> >> open up the case, and look for bare, burnt,
>
> >> or loose wires.
>
> >
>
> >This is the 3-pronged 220 volt cord connected to this dryer:
>
> > http://farm6.staticflickr.com/5495/10862520585_e4a63d0028_o.gif
>
> >
>
> >I think, IIRC, two of the prongs are 120 volt hot wires, 120 degrees
>
> >out of phase (that's the 220 volts); while the third, I think, is a
>
> >neutral wire.

>
>
>
> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>

> out of phase. ...and it should be 240V (twice 120V).
>
>

Nonsense. 180 deg out of phase and opposite sign are
the same thing. Hook up a scope and you'll see.

[tra...@optonline.net]

180 degrees out of phase and opposite are the same thing.
Look at it on an oscilloscope. What the exact method of
generating it is doesn't matter. If you have 3 wires entering
a box, the relationship between them is what it is, regardless
of how it's generated or what you call it.

[k...@attt.bizz]

On Sat, 16 Nov 2013 09:40:32 -0800 (PST), "tra...@optonline.net"
<tra...@optonline.net> wrote:

>On Saturday, November 16, 2013 12:09:37 PM UTC-5, k...@attt.bizz wrote:
>> On Sat, 16 Nov 2013 09:54:39 -0700, Tony Hwang <drag...@shaw.ca>
>>
>> wrote:
>>
>>
>>
>> >k...@attt.bizz wrote:
>>
>> >> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>>
>> >> <Grolea...@FreeShell.org> wrote:
>>
>> >>
>>
>> >>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>>
>> >>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>>
>> >>>> out of phase.
>>
>> >>>
>>
>> >>> Same thing
>>
>> >>
>>
>> >> No, it's not. It's one phase.
>>
>> >>
>>
>> >Hi,
>>
>> >It's called bi-phase. aka Edison circuit.
>>
>>
>>
>> Wrong. It's called "split-phase". ...because that's *exactly* what
>>
>> it is. Two-phase is something entirely different (and quite rare).
>
>180 degrees out of phase and opposite are the same thing.

No it's not. I thought you were an engineer.

>Look at it on an oscilloscope. What the exact method of
>generating it is doesn't matter. If you have 3 wires entering
>a box, the relationship between them is what it is, regardless
>of how it's generated or what you call it.

Wrong. But you're good at that.

[tra...@optonline.net]

On Friday, November 15, 2013 2:35:35 PM UTC-5, Ralph Mowery wrote:
> "Stormin Mormon" <cayo...@hotmail.com> wrote in message
>

> news:Nsohu.32667$8O5...@fx04.iad...
>
> > It sure seemed counter intuitive that the third prong would be neutral,
>
> > and the device is ungrounded. But, I found a couple web sites that say it
>
> > is. And says that it bonds the neutral to the frame. Go figure.
>
> >
>
>
>
> For common house circits there is no real electrical differance in the
>
> neutral and ground wires. They both start at the same point in the breaker
>
> panel and run parallel with each other to the socket or device that they are
>
> connected to.
>
>

There is however a big difference. The neutral carries current.
Unhook a neutral and grab hold of it in a properly functioning
circuit and you could be dead. Unhook a ground wire, and unless
something is malfunctioning, that can't happen.


.
>
> Mechanically there is often a differance. The ground will either be bare or
>
> green and the neutral will be white by the electrical code. They may even
>
> be differant sizes.
>
>
>
> When used in the 240 volt circuits the 4 th wire ground is just a redundant
>
> wire that is connected to the frame of the device . This is an added safety
>
> precaution incase for some reason the neutral wire would become disconnected
>
> if only a 3 wire circuit was used.

By that standard, the ground on any 3 prong 120V outlet is similarly
redundant. Could just as well connect the ground there to neutral.

[k...@attt.bizz]

Wrong. I thought you were an engineer.

[tra...@optonline.net]

Then instead of just saying "wrong", why don't
you explain the difference?

Test question:

A graph of three sine waves is given, A, B and C,
B is shifted 90 deg from A. C is shifted 180 deg
from A and looks like it's opposite.

Question:

1 - What is the phase realtionshiof B to A?

2 - What is the phase realtionship of C to A?

My answer to 1 is B is 90 deg out of phase relative
to A.

My answer to 2 is C is 180 deg out of phase relative
to A. To a lay person, it could also be called it's
"opposite".

How those waveforms are derived, what else you call
them in a particular application, doesn't change the
fact of what they are and their relationship to each
other. There are many ways that such voltage waveforms
could be generated. It doesn't change the fact that in
a 240V residential service the two hots are in fact
180 deg out of phase realtive to each other.

[Wes Groleau]

The reference is neutral. Each "hot" is 180º from the other when the
correct reference is used.


--
Wes Groleau

There are more Baroque musicians than any other kind.

[Wes Groleau]

On 11-16-2013, 12:48, tra...@optonline.net wrote:
> Unhook a neutral and grab hold of it in a properly functioning
> circuit and you could be dead. Unhook a ground wire, and unless
> something is malfunctioning, that can't happen.

Could be--IFF there were an available path to earth through you.

Otherwise, you might have absolutely no clue that you just did something
stupid.

[k...@attt.bizz]

On Sat, 16 Nov 2013 13:50:57 -0500, Wes Groleau

<Grolea...@FreeShell.org> wrote:

>On 11-16-2013, 11:34, k...@attt.bizz wrote:
>> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>> <Grolea...@FreeShell.org> wrote:
>>
>>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>>>> out of phase.
>>>
>>> Same thing
>>
>> No, it's not. It's one phase.
>

>The reference is neutral. Each "hot" is 180� from the other when the
>correct reference is used.

No, it's not. Words mean things. Phase has a particular meaning and
a phase shift and inversion are different things. In degenerate cases
they may look the same but they're not. Call things by their proper
names and communication gets easier. Or not, spread lies. Your
choice.

[k...@attt.bizz]

On Sat, 16 Nov 2013 10:50:51 -0800 (PST), "tra...@optonline.net"

<tra...@optonline.net> wrote:

>On Saturday, November 16, 2013 12:49:33 PM UTC-5, k...@attt.bizz wrote:
>> On Sat, 16 Nov 2013 09:37:19 -0800 (PST), "tra...@optonline.net"
>>
>> <tra...@optonline.net> wrote:
>>
>>
>>
>> >On Friday, November 15, 2013 7:58:24 PM UTC-5, k...@attt.bizz wrote:
>>
>> >> On Fri, 15 Nov 2013 01:25:56 +0000 (UTC), Danny D'Amico
>>
>> >>
>>
>> >> <dan...@is.invalid> wrote:
>>
>> >>
>>
>> >>
>>
>> >>
>>
>> >> >On Thu, 14 Nov 2013 15:55:24 -0500, Stormin Mormon wrote:
>>
>> >>
>>
>> >> >
>>
>> >>
>>
>> >> >> I'd pull the plug, check for continuity between
>>
>> >>
>>
>> >> >> power and ground prongs of the plug. I'd also
>>
>> >>
>>
>> >> >> open up the case, and look for bare, burnt,
>>
>> >>
>>
>> >> >> or loose wires.
>>
>> >>
>>
>> >> >
>>
>> >>
>>
>> >> >This is the 3-pronged 220 volt cord connected to this dryer:
>>
>> >>
>>
>> >> > http://farm6.staticflickr.com/5495/10862520585_e4a63d0028_o.gif
>>
>> >>
>>
>> >> >
>>
>> >>
>>
>> >> >I think, IIRC, two of the prongs are 120 volt hot wires, 120 degrees
>>
>> >>
>>
>> >> >out of phase (that's the 220 volts); while the third, I think, is a
>>
>> >>
>>
>> >> >neutral wire.
>>
>> >>
>>
>> >>
>>
>> >>
>>
>> >> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>>
>> >>
>>
>> >> out of phase. ...and it should be 240V (twice 120V).
>>
>> >>
>>
>> >>
>>
>> >
>>
>> >Nonsense. 180 deg out of phase and opposite sign are
>>
>> >the same thing. Hook up a scope and you'll see.
>>
>>
>>
>> Wrong. I thought you were an engineer.
>
>Then instead of just saying "wrong", why don't
>you explain the difference?

You claim to be an engineer. You should know better.

>Test question:
>
>A graph of three sine waves is given, A, B and C,
>B is shifted 90 deg from A. C is shifted 180 deg
>from A and looks like it's opposite.

For the simple degenerate case of a pure sign wave, they'll look the
same. That is *NOT* the general case and that is not how the words
are defined.

<irrelevance snipped - though I should snip everything you write>

>How those waveforms are derived, what else you call
>them in a particular application, doesn't change the
>fact of what they are and their relationship to each
>other. There are many ways that such voltage waveforms
>could be generated. It doesn't change the fact that in
>a 240V residential service the two hots are in fact
>180 deg out of phase realtive to each other.

Words mean things. You can use them to lie all you want but I'll call
you on it.

[Nightcrawler®]

"Stormin Mormon" <cayo...@hotmail.com> wrote in message news:cIIhu.235820$dn7.2...@fx20.iad...

The proper term is grounded conductor, and it is white.
The grounding conductor is green.

White carries device current/current imbalance.
The green/bare wire equalizes potential and provides a dedicated
fault path for the circuit breaker in case there is a short
to any bonded (to ground) metal surface/raceway where the
conductors are present.

There is no such thing as a neutral in a single phase application.

[Nightcrawler®]

"Stormin Mormon" <cayo...@hotmail.com> wrote in message news:gKIhu.235822$dn7....@fx20.iad...

Nothing wrong with that as long as the installation is
installed per code. You may ground every metal thing in
your house, if you want to.

[Nightcrawler®]

<k...@attt.bizz> wrote in message news:pp7f891bem3mp7tjk...@4ax.com...

> On Sat, 16 Nov 2013 11:35:17 -0500, k...@attt.bizz wrote:

<snip>

>
> It's also connected to the ground bus inside the box, not the neutral
> bus. Uninsulated, too.

Not always. Older, or cheap, load centers used to do this, but the
newer panels give a dedicated ground bus with a tapping screw to the
panel case and an isolated grounded conductor bus.

In some instances, in meter-main/load center combos, the tapping
screw may be allowed as the point at which the grounded conductor
obtains its bond to ground, but it is preferred to do this in the
meter section of all installations so that there is no messing things
up via some moron coming in at a later time and thinking that it
is all the same...

Why I hated residential work...

[Nightcrawler®]

"Tony Hwang" <drag...@shaw.ca> wrote in message news:prNhu.184076$lb1....@fx17.iad...

No, it is single phase, or split phase. Only one phase is
used and is center tapped to split the voltage. It is
impossible for this circuit to be out of phase with itself.

Bi, or to be more precise, two-phase, is a rare entity that
is primarily used in military applications, specifically in
aviation. My old Air Force generator had the ability to
provide two-phase, and pretty much anything else that you
wanted from selection of voltage to three-phase delta or wye.

[Danny D'Amico]

On Sat, 16 Nov 2013 13:40:02 -0600, Nightcrawler® wrote:

> The proper term is grounded conductor, and it is white.
> The grounding conductor is green.

Interestingly, mine has a white wire going to a green bolt.
http://farm3.staticflickr.com/2869/10891120223_3aa4c91eba_o.gif

:)

[Danny D'Amico]

On Sat, 16 Nov 2013 13:50:57 -0500, Wes Groleau wrote:

> The reference is neutral. Each "hot" is 180º from the other when the
> correct reference is used.

I had posted a detailed answer but it got lost since aioe is eating up
my posts, so, I'll reply again that I think they're 120 degrees out of
phase.

Here's why I think that.

The 3 wires on the street distribution line are all hot wires.
They come from a transformer (a whole series of them) which is wired
with three coils. Hence, they're each 120 degrees out of phase with
each other (Y or delta coils).

Then you take *two* of those hot wires, and send them into your house.
Those two are *still* 120 degrees out of phase (AFAIK).

You stick a neutral wire in between (which is just a wire to ground at
the poles) and now you have either two 120 volt circuits, or one three-wire
240 volt circuit.

The key point is that they're 120 degrees out of phase. I don't remember
the math, but that knocks the RMS (or whatever it's called) voltage to
something like 208 volts (but I don't remember the exact equation).

Anyway, since they're *not* 180 degrees out of phase, there will be
current in the neutral. Actually, I guess if the two hot wires are
not used for anything else, i.e., if they're a *dedicated* circuit,
I'm not sure if any current still goes into the neutral.

Does anyone know if dryers are dedicated circuits?
If so, is there any current going into the neutral?

Note: If they were *not* dedicated circuits, then for sure there could
easily be current in the neutral since the loads wouldn't be balanced
all the time.

[Danny D'Amico]

On Sat, 16 Nov 2013 10:50:51 -0800, tra...@optonline.net wrote:

> It doesn't change the fact that in
> a 240V residential service the two hots are in fact
> 180 deg out of phase realtive to each other.

I'm pretty sure I learned, long ago, that they're 120 degrees
out of phase with each other.

The reason, IIRC, has to do with the fact that they generate
electricity with three coils. And *those* three coils are wound
symmetrically (i.e., in a Y or delta) which makes them 120 degrees
out of sync.

So, each of the three wires coming out of the power company
(which are the three wires on the poles along the street) are
120 degrees out of sync (if I'm correct).

You only get *two* of those wires going into your house.
But they're still 120 degrees out of sync (AFAIK).

Besides, if they were 180 degrees out of sync, what would
the third wire be on that pole?

[Danny D'Amico]

On Sat, 16 Nov 2013 09:48:29 -0800, tra...@optonline.net wrote:

> The neutral carries current.

Yup. The neutral carries current, a ground isn't supposed to carry
current (unless something goes wrong).

That's why it threw me when I realized this neutral is connected
to the case of the dryer.

http://farm8.staticflickr.com/7452/10890812215_27f1549d6d_o.gif

So, I do see that the ground and the neutral are muddled here,
in that the neutral is also the ground for the dryer frame.

So, I guess, a neutral can also function as a ground; but I
wouldn't want to see a ground functioning also as a neutral.

NOTE: I sure *hope* the ground wires and neutral wires are attached
to *different* points (both at zero potential) at the circuit panel.

I had always thought the ground goes into the ground at the house;
but that the neutral goes into the ground at the pole (and not
necessarily the first pole from the house but not more than 2 or
3 poles after the house).

Is any of that correct? Or am I wrong (again)?

[Danny D'Amico]

On Sat, 16 Nov 2013 12:05:12 -0500, Ralph Mowery wrote:

> As most dryers use the 120 volts from one leg to power the
> control circuits and light , the third wire is acting as a neutral.

Well, that answers my question as to whether the neutral is carrying
current.

Since there are 120v "things" on that dryer (e.g., the timer, the
bulbs, etc.), there *must* be some current in that neutral (unless
the loads are perfectly balanced).

So, in the case of my 3-wire dryer, the neutral is always carrying
current, whereas a ground wire shouldn't normally be carrying current
(because once you carry current, there is a chance that there will
be resistance, and if there is resistance, you get a potential,
whether you like it or not).

So, maybe, just maybe, my spark, is due to a high-resistance neutral?
Geez. How do I check for a high-resistance neutral?

[Nightcrawler®]

"Danny D'Amico" <da...@is.invalid> wrote in message news:l68ii0$365$7...@solani.org...

It is wrong of them to do this, but I guess some moron engineer
thought this would not confuse someone, though in this application
I do not see how. In a hard wired installation, yes. Still wrong.
Bonding jumpers are to be green/bare/yellow with green stripe if
you are into non-American color coding.

That wire still needs to be terminated, or have a separate wire,
terminated to the center terminal. This will be your chassis ground
or what is called a bonding jumper.

[Nightcrawler®]

"Danny D'Amico" <da...@is.invalid> wrote in message news:l68jfm$365$1...@solani.org...

Time for football. TTYL

[Nightcrawler®]

"Danny D'Amico" <da...@is.invalid> wrote in message news:l68iv7$365$8...@solani.org...

As an aside, I would trace that wire and find out where it goes. Odds
are that it is supposed to be terminated to the center terminal.

[Danny D'Amico]

On Fri, 15 Nov 2013 23:40:45 -0600, Nightcrawler® wrote:

> I have a simple question that might clear some things up. The
> two hot wires, are they wrapped around a bare cable that is
> secured at the house and the power pole?

I do not know the answer to that question, but, I do know that
all the hot wires on the distribution power poles are supposedly bare.

[Mark Lloyd]

On 11/16/2013 05:31 AM, Stormin Mormon wrote:
> On 11/15/2013 7:58 PM, k...@attt.bizz wrote:
>>
>>> So, there is no ground that I know of, if I understood this correctly.
>>> That's why I asked if you guys ADD a ground wire in this situation?
>>> http://farm4.staticflickr.com/3753/10862565466_e2473a60a8_o.gif
>>
>> The ground is a must, for safety. At one time, it was allowed to run
>> the timer current though ground. A neutral conductor is now required
>> for that current.
>>
>
> I've been trying to figure if the cold wire of a
> three wire dryer is a neutral or ground. I'd thought
> it was a ground, but some folks on the list and
> on the web thought it's a neutral.
>

I'm looking at the receptacle chart at
www.repeater-builder.com/tech-info/pdfs/nema-non-locking.pdf

The normal three-wire dryer receptacle appears to be on line 10
(125/250V). This receptacle has 2 hots and neutral. This is different
from line 6 (250V with ground).

--
39 days until The winter celebration (Wednesday December 25, 2013 12:00
AM for 1 day).

Mark Lloyd
http://notstupid.us

"It is the creationists who blasphemously are claiming that God is
cheating us in a stupid way." [J. W. Nienhuys]

[sam E]

On 11/16/2013 10:34 AM, k...@attt.bizz wrote:
> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
> <Grolea...@FreeShell.org> wrote:
>
>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>>> out of phase.
>>
>> Same thing
>
> No, it's not. It's one phase.
>

If the angle between the phases was anything other than 180, would you
call it 2 phase? If so, why this oddity?

[Danny D'Amico]

On Fri, 15 Nov 2013 23:19:41 -0500, Ralph Mowery wrote:

> I don't see any provision for a strap from the dryer frame to the center
> neutral connection for that particular dryer. It would be good to know where
> that white wire that is under the ground screw comes from.

I think this white wire is the 'strap':
http://farm3.staticflickr.com/2869/10891120223_3aa4c91eba_o.gif

> can you give the make and model of the dryer so I
> can look for a wiring diagram for it ? If you have the book for it, it may
> have the diagram in it for a 4 and 3 wire hookup.

It's a Whirlpool Duet Sport (from Costco); I don't have any manuals.

Sorry this took so long. I had to switch newsservers because aioe
was triplicating posts, and then dropping them because of the errors. Sigh.

[Mark Lloyd]

On 11/16/2013 10:44 AM, Stormin Mormon wrote:
> On 11/16/2013 11:35 AM, k...@attt.bizz wrote:
>> On Sat, 16 Nov 2013 06:31:21 -0500, Stormin Mormon

>>> I've been trying to figure if the cold wire of a
>>> three wire dryer is a neutral or ground. I'd thought
>>> it was a ground, but some folks on the list and
>>> on the web thought it's a neutral.
>>

>> It *is* a ground. It's connected to the case of the appliance. Would
>> you connect a neutral to the case?
>>
>
> Oh, now I'm all confused.
>

I remember something about a ground connection being no more than 1V
from true ground. According to that definition, the third wire could be
ground.

Then neutral is a grounded current carrying conductor. This wire is
neutral too.

[Mark Lloyd]

On 11/16/2013 11:09 AM, k...@attt.bizz wrote:
> On Sat, 16 Nov 2013 09:54:39 -0700, Tony Hwang <drag...@shaw.ca>
> wrote:
>

>> k...@attt.bizz wrote:
>>> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>>> <Grolea...@FreeShell.org> wrote:
>>>
>>>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>>>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>>>>> out of phase.
>>>>
>>>> Same thing
>>>
>>> No, it's not. It's one phase.
>>>

>> Hi,
>> It's called bi-phase. aka Edison circuit.
>

> Wrong. It's called "split-phase". ...because that's *exactly* what
> it is.

"phase" has a meaning. There's still 2 of them. "split-phase" sounds
right too.

> Two-phase is something entirely different (and quite rare).
>

I think I've heard about that. Are the phases 90 degrees apart?

The fact that there is this different 2 phase system doesn't prevent the
usual one from being 2 phase. That's be like saying you don't have 2
colors of holiday lights if they're just red and green.

[Mark Lloyd]

On 11/16/2013 12:50 PM, tra...@optonline.net wrote:

[snip]

> How those waveforms are derived, what else you call
> them in a particular application, doesn't change the
> fact of what they are and their relationship to each
> other. There are many ways that such voltage waveforms
> could be generated. It doesn't change the fact that in
> a 240V residential service the two hots are in fact
> 180 deg out of phase realtive to each other.
>

I think the people who are denying that it (residential 120/240) is
2-phase are considering the (1-phase) connection to the transformer
primary. You still have 2 phases inside.

You could be using 2 120V transformers (primaries in parallel,
secondaries in series with ground between then), a generator with a
2-phase (180 deg apart) output, or even 2 120V (synchronized)
generators. You still have 2 phases.

[Ralph Mowery]

"Danny D'Amico" <da...@is.invalid> wrote in message

news:l68m3g$qkj$4...@solani.org...

> On Fri, 15 Nov 2013 23:19:41 -0500, Ralph Mowery wrote:
>
>> I don't see any provision for a strap from the dryer frame to the center
>> neutral connection for that particular dryer. It would be good to know
>> where
>> that white wire that is under the ground screw comes from.
>
> I think this white wire is the 'strap':
> http://farm3.staticflickr.com/2869/10891120223_3aa4c91eba_o.gif
>
>> can you give the make and model of the dryer so I
>> can look for a wiring diagram for it ? If you have the book for it, it
>> may
>> have the diagram in it for a 4 and 3 wire hookup.
>
> It's a Whirlpool Duet Sport (from Costco); I don't have any manuals.
>

The manual is here:
https://docs.google.com/file/d/0B5If-wTgYWH5MDQ4MjcxMTEtZGI3Yy00MzRlLTlmMTMtZmVlMWMwZGU5MGI4/edit?usp=drive_web&hl=en&pli=1

From the manual, you seem to have it wired correctly for a 3 wire cord. The
white wire that is connected to the screw at the frame on the left side of
your picture goes to the neutral to give you 120 volt power where it is
needed. This is probably the way it comes from the factory as the diagram
says "neutral terminal linked to cabinet. The symble that looks like a 3
prong rake with the W over it is a symble for the frame of an electrical
device. The W is for a white wire.


That wire would be reconnected to a differant place if 4 wires are used.

If you unplug your dryer there should be way less than one ohm (small
ammount due to about 5 feet of wire) to the wire going from the neutral of
the plug to the center terminal on the dryer and also to the frame of the
dryer.

[Ralph Mowery]

"Mark Lloyd" <ma...@this.is.not.email.invalid> wrote in message
news:%rRhu.190560$eE7....@fx21.iad...

>
> I think the people who are denying that it (residential 120/240) is
> 2-phase are considering the (1-phase) connection to the transformer
> primary. You still have 2 phases inside.
>
> You could be using 2 120V transformers (primaries in parallel, secondaries
> in series with ground between then), a generator with a 2-phase (180 deg
> apart) output, or even 2 120V (synchronized) generators. You still have 2
> phases.
>

This single phase/two phase thing is almost as bad as the WD40 threads.

In the normal house at the pole (on the ground or where ever) the secondary
is a center tapped single phase feed to the house. There is very little 2
phase in the US. What is on the other side of the transformer going back
to the power company does not mater at all. The transformer converts it to
a center tapped single phase feed to the house.

[Nightcrawler®]

"Danny D'Amico" <da...@is.invalid> wrote in message news:l68l8t$qkj$3...@solani.org...

You can't go outside and look at it? It is rather obvious.

[Nightcrawler®]

"sam E" <sa...@dont.send.email.invalid> wrote in message news:3YQhu.454878$i75.4...@fx03.iad...

http://en.wikipedia.org/wiki/Two-phase_electric_power

[k...@attt.bizz]

On Sat, 16 Nov 2013 20:04:33 +0000 (UTC), Danny D'Amico
<da...@is.invalid> wrote:

>On Sat, 16 Nov 2013 10:50:51 -0800, tra...@optonline.net wrote:
>
>> It doesn't change the fact that in
>> a 240V residential service the two hots are in fact
>> 180 deg out of phase realtive to each other.
>
>I'm pretty sure I learned, long ago, that they're 120 degrees
>out of phase with each other.

Nope. If you must assign a phase relationship (though it's
technically wrong) it would be 180 degrees. The phases in a
three-phase system are 120 degrees apart. Remember, a circle is 360
degrees (what happened to metric?).

>The reason, IIRC, has to do with the fact that they generate
>electricity with three coils. And *those* three coils are wound
>symmetrically (i.e., in a Y or delta) which makes them 120 degrees
>out of sync.

Yes, the generators are three-phase, as is the distribution system.

>So, each of the three wires coming out of the power company
>(which are the three wires on the poles along the street) are
>120 degrees out of sync (if I'm correct).

So far, so good.

>You only get *two* of those wires going into your house.
>But they're still 120 degrees out of sync (AFAIK).

Nope, you only get one, and that one is split in half, using a
center-tapped transformer (center goes to ground/neutral).

>Besides, if they were 180 degrees out of sync, what would
>the third wire be on that pole?

You only see one of the three. Your neighbor might be 120degrees from
you (on another leg of the three phases) but you can't see that.

[k...@attt.bizz]

On Sat, 16 Nov 2013 15:09:54 -0600, Mark Lloyd
<ma...@this.is.not.email.invalid> wrote:

>On 11/16/2013 11:09 AM, k...@attt.bizz wrote:
>> On Sat, 16 Nov 2013 09:54:39 -0700, Tony Hwang <drag...@shaw.ca>
>> wrote:
>>
>>> k...@attt.bizz wrote:
>>>> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>>>> <Grolea...@FreeShell.org> wrote:
>>>>
>>>>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>>>>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>>>>>> out of phase.
>>>>>
>>>>> Same thing
>>>>
>>>> No, it's not. It's one phase.
>>>>
>>> Hi,
>>> It's called bi-phase. aka Edison circuit.
>>
>> Wrong. It's called "split-phase". ...because that's *exactly* what
>> it is.
>
>"phase" has a meaning. There's still 2 of them. "split-phase" sounds
>right too.
>
>> Two-phase is something entirely different (and quite rare).
>>
>
>I think I've heard about that. Are the phases 90 degrees apart?

Yes. From it, any variation or number of phases can be easily
generated (efficiently). It's just a little trig and a transformer.

>The fact that there is this different 2 phase system doesn't prevent the
>usual one from being 2 phase. That's be like saying you don't have 2
>colors of holiday lights if they're just red and green.

Words mean things. The proper term for the Edison connection is
"split-phase". It *is* a single phase that is split by a
center-tapped transformer (center grounded).

[k...@attt.bizz]

On Sat, 16 Nov 2013 13:51:46 -0600, Nightcrawler�
<dirty...@dirtcheap.org> wrote:

>
>"Tony Hwang" <drag...@shaw.ca> wrote in message news:prNhu.184076$lb1....@fx17.iad...
>> k...@attt.bizz wrote:
>>> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>>> <Grolea...@FreeShell.org> wrote:
>>>
>>>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>>>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>>>>> out of phase.
>>>>
>>>> Same thing
>>>
>>> No, it's not. It's one phase.
>>>
>> Hi,
>> It's called bi-phase. aka Edison circuit.
>
>No, it is single phase, or split phase. Only one phase is
>used and is center tapped to split the voltage. It is
>impossible for this circuit to be out of phase with itself.

+1

One leg is the opposite of the other by the very nature of the
transformer.

>Bi, or to be more precise, two-phase, is a rare entity that
>is primarily used in military applications, specifically in
>aviation. My old Air Force generator had the ability to
>provide two-phase, and pretty much anything else that you
>wanted from selection of voltage to three-phase delta or wye.
>

Precisely. It starts with the two phases in quadrature (90 degrees)
and a transformer to generate any desired phase relationship.

[k...@attt.bizz]

Probably. Not sure what your question is, but 2-phase, where the two
are 90 degrees apart is interesting in that any phase relationship and
any number of phases can be generated with simple transformers and a
(very small) bit of trigonometry. It's quite useful but exceedingly
rare.

Two phases generated 180 degrees from each other make no sense at all.
It's no more efficient (less, actually) than single-phase and much
less efficient than three-phase. There are all sorts of other
alternatives, as well. Six-phase is somewhat interesting at times but
it's not as efficient as three phase. There's a reason the world uses
three.

[k...@attt.bizz]

On Sat, 16 Nov 2013 20:18:17 +0000 (UTC), Danny D'Amico
<da...@is.invalid> wrote:

>On Sat, 16 Nov 2013 12:05:12 -0500, Ralph Mowery wrote:
>
>> As most dryers use the 120 volts from one leg to power the
>> control circuits and light , the third wire is acting as a neutral.
>
>Well, that answers my question as to whether the neutral is carrying
>current.
>
>Since there are 120v "things" on that dryer (e.g., the timer, the
>bulbs, etc.), there *must* be some current in that neutral (unless
>the loads are perfectly balanced).

Yes, though it's possible to balance the two, it would be quite
expensive to perfectly do so under all conditions. The fourth wire is
cheaper.

>So, in the case of my 3-wire dryer, the neutral is always carrying
>current, whereas a ground wire shouldn't normally be carrying current
>(because once you carry current, there is a chance that there will
>be resistance, and if there is resistance, you get a potential,
>whether you like it or not).

Sure.

>So, maybe, just maybe, my spark, is due to a high-resistance neutral?
>Geez. How do I check for a high-resistance neutral?

It would have to be a very high resistance neutral to get a spark.
Even if there is no neutral, the voltage on the common point (the
neutral on the dryer) would be very close to ground. The imbalance is
proportional to the ratio of the current in the heater and the timer.
You would measure resistance with an ohm meter. ;-)

[k...@attt.bizz]

On Sat, 16 Nov 2013 15:28:26 -0600, Mark Lloyd
<ma...@this.is.not.email.invalid> wrote:

>On 11/16/2013 12:50 PM, tra...@optonline.net wrote:
>
>[snip]
>
>> How those waveforms are derived, what else you call
>> them in a particular application, doesn't change the
>> fact of what they are and their relationship to each
>> other. There are many ways that such voltage waveforms
>> could be generated. It doesn't change the fact that in
>> a 240V residential service the two hots are in fact
>> 180 deg out of phase realtive to each other.
>>
>
>I think the people who are denying that it (residential 120/240) is
>2-phase are considering the (1-phase) connection to the transformer
>primary. You still have 2 phases inside.

No, that's wrong. You only have one phase. It is split into two
legs. Words mean things.

[tra...@optonline.net]

On Saturday, November 16, 2013 6:07:17 PM UTC-5, k...@attt.bizz wrote:
> On Sat, 16 Nov 2013 13:51:46 -0600, Nightcrawler®
>
> <dirty...@dirtcheap.org> wrote:
>
>
>
> >
>
> >"Tony Hwang" <drag...@shaw.ca> wrote in message news:prNhu.184076$lb1....@fx17.iad...
>
> >> k...@attt.bizz wrote:
>
> >>> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>
> >>> <Grolea...@FreeShell.org> wrote:
>
> >>>
>
> >>>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>
> >>>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>
> >>>>> out of phase.
>
> >>>>
>
> >>>> Same thing
>
> >>>
>
> >>> No, it's not. It's one phase.
>
> >>>
>
> >> Hi,
>
> >> It's called bi-phase. aka Edison circuit.
>
> >
>
> >No, it is single phase, or split phase. Only one phase is
>
> >used and is center tapped to split the voltage. It is
>
> >impossible for this circuit to be out of phase with itself.
>
>
>
> +1
>

No one is claiming anything is out of phase with itself.
The simple statement was made that one of the hot legs
of a 240V dryer is out of phase with the other by 180 degrees.
Look at them on a scope, what do you see? Phase in this
context is just the relationship of one waveform to another.
Two waveforms can differ in phase from 0 to 360 deg. With a
sine wave, when one differs from the other by 180 deg, they
can also be said to be the opposite of each other.

>
> One leg is the opposite of the other by the very nature of the
>
> transformer.
>

Correct. And when you have one sine wave that is the opposite
of the other, it's a 180 deg phase difference. Look at it
on a scope or graph it. It doesn't matter how exactly the waveform
difference is generated.

[tra...@optonline.net]

On Saturday, November 16, 2013 1:59:09 PM UTC-5, k...@attt.bizz wrote:
> On Sat, 16 Nov 2013 13:50:57 -0500, Wes Groleau

>
> <Grolea...@FreeShell.org> wrote:
>
>
>
> >On 11-16-2013, 11:34, k...@attt.bizz wrote:
>
> >> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>
> >> <Grolea...@FreeShell.org> wrote:
>
> >>
>
> >>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>
> >>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>
> >>>> out of phase.
>
> >>>
>
> >>> Same thing
>
> >>
>
> >> No, it's not. It's one phase.
>
> >
>

> >The reference is neutral. Each "hot" is 180º from the other when the
>
> >correct reference is used.
>
>
>

> No, it's not. Words mean things. Phase has a particular meaning

Yes and in electrical engineering, the most widely used context
of "phase" is simply the relationship of one cyclical waveform
to another. Hence, the two dryer hot legs are in fact 180 deg
out of phase with each other. Look at them on a scope. What do
you see?



and
>
> a phase shift and inversion are different things.

From the electron's perspective, a mathematical perspective,
a physics perspective, what exactly is the
difference between saying two signals, waveforms, circuit
points, etc are 180 deg out of phase or that one is the inversion
of the other?



In degenerate cases
>
> they may look the same but they're not. Call things by their proper
>
> names and communication gets easier. Or not, spread lies. Your
>
> choice.

He is calling things by their proper name. You're
insisting that a 180 def phase difference of two waveforms
must be called "opposite" and not a 180 deg phase difference.

http://en.wikipedia.org/wiki/Phase_(waves)

Phase difference is the difference, expressed in electrical degrees or time, between two waves having the same frequency and referenced to the same point in time.[1] Two oscillators that have the same frequency and no phase difference are said to be in phase. Two oscillators that have the same frequency and different phases have a phase difference, and the oscillators are said to be out of phase with each other. The amount by which such oscillators are out of phase with each other can be expressed in degrees from 0° to 360°, or in radians from 0 to 2π. If the phase difference is 180 degrees (π radians), then the two oscillators are said to be in antiphase.

[tra...@optonline.net]

On Saturday, November 16, 2013 3:01:43 PM UTC-5, Danny D'Amico wrote:

> On Sat, 16 Nov 2013 13:50:57 -0500, Wes Groleau wrote:
>
>
>
> > The reference is neutral. Each "hot" is 180º from the other when the
>
> > correct reference is used.
>
>
>

> I had posted a detailed answer but it got lost since aioe is eating up
>

> my posts, so, I'll reply again that I think they're 120 degrees out of
>
> phase.
>
>

I replied to your original post explaining why you're wrong.

>
> Here's why I think that.
>
>
>
> The 3 wires on the street distribution line are all hot wires.
>
> They come from a transformer (a whole series of them) which is wired
>
> with three coils. Hence, they're each 120 degrees out of phase with
>
> each other (Y or delta coils).
>
>
>
> Then you take *two* of those hot wires, and send them into your house.
>

> Those two are *still* 120 degrees out of phase (AFAIK).
>
>

That is where you're going wrong. You don't take two of the three
phase wires, you take ONE of them and put it through a center pole
step-down transformer. That gives you two hots and a center connection.
Between either hot and
the center connection you have 120V. Between the two hots you have
240V. The center tap becomes the neutral. If you look at the
waveforms of the two hots relative to the neutral, they are 180 deg
opposite each other.

>
> You stick a neutral wire in between (which is just a wire to ground at
>
> the poles) and now you have either two 120 volt circuits, or one three-wire
>
> 240 volt circuit.
>
>
>
> The key point is that they're 120 degrees out of phase. I don't remember
>
> the math, but that knocks the RMS (or whatever it's called) voltage to
>
> something like 208 volts (but I don't remember the exact equation).
>
>
>
> Anyway, since they're *not* 180 degrees out of phase, there will be
>
> current in the neutral. Actually, I guess if the two hot wires are
>
> not used for anything else, i.e., if they're a *dedicated* circuit,
>
> I'm not sure if any current still goes into the neutral.
>
>

Per the above, all that is wrong.

>
> Does anyone know if dryers are dedicated circuits?

Yes, at least every one I've ever seen.

>
> If so, is there any current going into the neutral?
>
>

Again, as others have pointed out, the unbalanced portion
of the load current, which might be lights, timer, etc.
is flowing in the neutral

>
> Note: If they were *not* dedicated circuits, then for sure there could
>
> easily be current in the neutral since the loads wouldn't be balanced
>
> all the time.

If a neutral is required for an appliance, then it should
always be assumed that current is flowing in it.

[tra...@optonline.net]

On Saturday, November 16, 2013 6:12:14 PM UTC-5, k...@attt.bizz wrote:
> On Sat, 16 Nov 2013 14:54:22 -0600, sam E
>
> <sa...@dont.send.email.invalid> wrote:
>
>
>
> >On 11/16/2013 10:34 AM, k...@attt.bizz wrote:
>
> >> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>
> >> <Grolea...@FreeShell.org> wrote:
>
> >>
>
> >>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>
> >>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>
> >>>> out of phase.
>
> >>>
>
> >>> Same thing
>
> >>
>
> >> No, it's not. It's one phase.
>
> >>
>
> >
>
> >If the angle between the phases was anything other than 180, would you
>
> >call it 2 phase? If so, why this oddity?
>
>
>
> Probably. Not sure what your question is,

I believe his question is the same one I have, which is why
you insist on referring to a 180 deg phase difference between two AC waveforms only as "opposite" and deny that it is also correct that they differ by 180 degrees in phase. 180 deg is just one possible relationship between two
waveforms, where one is the opposite of the other. And that is what
you have at the dryer connection.

but 2-phase, where the two
>
> are 90 degrees apart is interesting in that any phase relationship and
>
> any number of phases can be generated with simple transformers and a
>
> (very small) bit of trigonometry. It's quite useful but exceedingly
>
> rare.
>
>
>
> Two phases generated 180 degrees from each other make no sense at all.

Except of course to run the dryer, because regardless of
whatever you want to call it, there are two hots going to that
dryer that differ in phase by 180 deg. If you were in an EE
physics, or math course and they presented you with a voltage vs time
graph of two waveforms that you would get from an oscilloscope
hooked up to:

Hot 1 to neutral and
Hot 2 to neutral

And they asked, what is the phase relationship of these
two voltage waveforms, what would your answer be?

[Tony Hwang]

k...@attt.bizz wrote:
> On Sat, 16 Nov 2013 09:54:39 -0700, Tony Hwang <drag...@shaw.ca>
> wrote:
>

>> k...@attt.bizz wrote:
>>> On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
>>> <Grolea...@FreeShell.org> wrote:
>>>
>>>> On 11-15-2013, 19:58, k...@attt.bizz wrote:
>>>>> 180 degrees, but technically, no. It's opposite sign, not 180 degrees
>>>>> out of phase.
>>>>
>>>> Same thing
>>>
>>> No, it's not. It's one phase.
>>>

>> Hi,
>> It's called bi-phase. aka Edison circuit.
>

> Wrong. It's called "split-phase". ...because that's *exactly* what

> it is. Two-phase is something entirely different (and quite rare).
>
Hi,
Draw the wiring out to visualize, it is just one winding with center tap!

[Nightcrawler®]

"Tony Hwang" <drag...@shaw.ca> wrote in message news:GsUhu.184114$0q6.1...@fx26.iad...

> Hi,
> Draw the wiring out to visualize, it is just one winding with center tap!

two-phase and split phase are different. Reference previous link to two-phase

http://en.wikipedia.org/wiki/Split-phase_electric_power