Here is a picture of the incoming wires to my main circuit breaker:
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

If we follow those three wires *back* to the nearest transformer, what
do they look like (in terms of phase relationship to each other)?

If we follow those three wires *forward* to the first circuit breaker,
what do they look like (in terms of connection to the literal earth of
the ground)?

Note: This question is an offshoot of a 220v dryer question; but this
question is asked to get to the root of *what* it is that is entering
the house in the first place.

Danny D'Amico wrote:
Here is a picture of the incoming wires to my main circuit breaker:
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

If we follow those three wires *back* to the nearest transformer, what
do they look like (in terms of phase relationship to each other)?

If we follow those three wires *forward* to the first circuit breaker,
what do they look like (in terms of connection to the literal earth of
the ground)?

Note: This question is an offshoot of a 220v dryer question; but this
question is asked to get to the root of *what* it is that is entering
the house in the first place.

Hmmm,
Your question has been answered more than once throughout this thread.
If still did not get it. You really ought to follow the wires upto the
main breaker panel. One note: Gnd and Neutral is connected together but
they are not same in functionality in the circuit.

On Mon, 18 Nov 2013 01:42:15 +0000 (UTC), Danny D'Amico
wrote:

Here is a picture of the incoming wires to my main circuit breaker:
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

If we follow those three wires *back* to the nearest transformer, what
do they look like (in terms of phase relationship to each other)?

?? They're wires. It looks the same.

If we follow those three wires *forward* to the first circuit breaker,
what do they look like (in terms of connection to the literal earth of
the ground)?

It's wires. It looks the same.

Note: This question is an offshoot of a 220v dryer question; but this
question is asked to get to the root of *what* it is that is entering
the house in the first place.

The same as it does at the transformer and the dryer.

Danny D'Amico wrote:
Here is a picture of the incoming wires to my main circuit breaker:
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

If we follow those three wires *back* to the nearest transformer, what
do they look like (in terms of phase relationship to each other)?

If we follow those three wires *forward* to the first circuit breaker,
what do they look like (in terms of connection to the literal earth of
the ground)?

Note: This question is an offshoot of a 220v dryer question; but this
question is asked to get to the root of *what* it is that is entering
the house in the first place.

Hi,
How is your house electric system grounded? I still think your dryer is
not grounded well. Measure between the dryer chassis(body) and ground
point in Ohm scale on your meter. Do you read zero Ohm or fraction of Ohm?
Also you should read zero Ohm between gnd(dryer body) and neutral on
your dryer.

If it is all OK, some one else mentioned heating element sagging when
hot rubbing on the dryer chassis not enough to kick the breaker but give
spark and shock specially when hand is moist(doing washing)

I think this thread is coming to an end.

This web page won't put up my posts if they're more than about 10 or 15 lines long.

Danny:

In the following e-mail address, each letter has been replaced with the letter or symbol to the right of it on a standard Qwerty keyboard.

If you can e-mail me, I'll send you a write-up that answers your question on what goes on both upstream and downstream of your electrical panel.

m l r ; r n s u # o ; p d / m r y

Leave out the spaces and type the letters to the left of the ones shown above to get my correct e-mail address. I put spaces in because if you type the letters r and n without a space between them, it looks like an m, and for this to work, the e-mail address you type has to be exactly correct.

So far as an electrical spark inside the dryer goes, I would look for any wires inside the dryer that are rubbing against the rotating dryer drum. In time, the drum will rub it's way through the insulation, and contact the copper conductor. Then, depending on WHICH wire is rubbing against the drum, you can get a shock from the dryer by touching the drum while it's running, or only when the heating element is heating, or only during the Permanent Press cool down cycle, or whatever. I'd at least make sure that no wires are touching the rotating drum.

On 11/17/2013 08:42 PM, Danny D'Amico wrote:
Here is a picture of the incoming wires to my main circuit breaker:
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

If we follow those three wires*back* to the nearest transformer, what
do they look like (in terms of phase relationship to each other)?

180 out of phase aka 2-phase or split-phase.

On Sunday, November 17, 2013 8:42:15 PM UTC-5, Danny D'Amico wrote:
Here is a picture of the incoming wires to my main circuit breaker:

http://farm3.staticflickr.com/2886/1...21cf1404_o.gif



If we follow those three wires *back* to the nearest transformer, what

do they look like (in terms of phase relationship to each other)?



If we follow those three wires *forward* to the first circuit breaker,

what do they look like (in terms of connection to the literal earth of

the ground)?



Note: This question is an offshoot of a 220v dryer question; but this

question is asked to get to the root of *what* it is that is entering

the house in the first place.


All of the above has been explained to you in the other thread you started.

On Sunday, November 17, 2013 8:42:15 PM UTC-5, Danny D'Amico wrote:
Here is a picture of the incoming wires to my main circuit breaker:

http://farm3.staticflickr.com/2886/1...21cf1404_o.gif



If we follow those three wires *back* to the nearest transformer, what

do they look like (in terms of phase relationship to each other)?



If we follow those three wires *forward* to the first circuit breaker,

what do they look like (in terms of connection to the literal earth of

the ground)?



Note: This question is an offshoot of a 220v dryer question; but this

question is asked to get to the root of *what* it is that is entering

the house in the first place.

I may have worked for your dad in Miami before George Bush and the CIA kidnapped me and broke my back.
Violently overthrow the US government

On Monday, November 18, 2013 2:22:35 AM UTC-5, nestork wrote:
This web page won't put up my posts if they're more than about 10 or 15

lines long.



Danny:



In the following e-mail address, each letter has been replaced with the

letter or symbol to the right of it on a standard Qwerty keyboard.



If you can e-mail me, I'll send you a write-up that answers your

question on what goes on both upstream and downstream of your electrical

panel.



m l r ; r n s u # o ; p d / m r y



Leave out the spaces and type the letters to the left of the ones shown

above to get my correct e-mail address. I put spaces in because if you

type the letters r and n without a space between them, it looks like an

m, and for this to work, the e-mail address you type has to be exactly

correct.



Good grief. What's next, NSA level encryption?

I hate to display ignorance, and I know I should know this.

But maybe somebody can explain.

The power lines are 3 phase, meaning they're 120 degrees out of phase to each other allowing 3 wires to carry what 6 wires should (since they're generated by 3 sets of coils at the power plant).

The house is fed by just one of these wires, through a center tap transformer. That transformer sends 3 wires to the house: Neutral, +120 volts, -120 volts. Connect the two hots and you get 240, connect either hot to the neutral and you get 120. Your safety ground is bonded to the neutral and so you should also have 120 from any hot wire to the ground. Neutral is the center tap.

Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.

On Monday, November 18, 2013 9:39:55 AM UTC-5, TimR wrote:
I hate to display ignorance, and I know I should know this.



But maybe somebody can explain.



The power lines are 3 phase, meaning they're 120 degrees out of phase to each other allowing 3 wires to carry what 6 wires should (since they're generated by 3 sets of coils at the power plant).


The 6 vs three makes no sense.





The house is fed by just one of these wires, through a center tap transformer. That transformer sends 3 wires to the house: Neutral, +120 volts, -120 volts. Connect the two hots and you get 240, connect either hot to the neutral and you get 120. Your safety ground is bonded to the neutral and so you should also have 120 from any hot wire to the ground. Neutral is the center tap.



Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.

All the neutrals are tied to ground. Why would you expect
the neutral on the secondary to not be at ground level?
In the strictist sense, if you take a center tap transformer,
the secondary side doesn't have to have any relationship
to the potential on the primary side. It's can be completely
seperate, it's a seperate winding not connected to the primary.
What and how you hook it up
determines what level anything is referenced to. In the power
transformer case, the center tap (neutral) is tied to ground.

On Monday, November 18, 2013 9:48:27 AM UTC-5, wrote:
Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.



All the neutrals are tied to ground. Why would you expect

the neutral on the secondary to not be at ground level?

In the strictist sense, if you take a center tap transformer,

the secondary side doesn't have to have any relationship

to the potential on the primary side. It's can be completely

seperate, it's a seperate winding not connected to the primary.

What and how you hook it up

determines what level anything is referenced to. In the power

transformer case, the center tap (neutral) is tied to ground.

Well, you're not seeing the problem. I wish I could draw here.

Your transformer has two wires going in, and three going out.

I don't know what primary is in my neighbor hood, let's say 2400 vac for an example. Which two wires do we use? You only have the choice of leg to leg, or leg to neutral.

Choose leg to neutral: use a 10 to 1 turns ratio, your secondary will be 240 volts line to line. Then center tap it, and you get 120 from each line to center.

BUT: why would center tap be anywhere near neutral?

Choose leg to leg: does the same problem exist?

Once it gets into the house I understand how it works, but on the pole I'm hazy.

By the way you are dead wrong on the 6 wires thing. That part I do remember.

On 11/18/2013 9:08 AM, TimR wrote:
On Monday, November 18, 2013 9:48:27 AM UTC-5, wrote:
Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.



All the neutrals are tied to ground. Why would you expect

the neutral on the secondary to not be at ground level?

In the strictist sense, if you take a center tap transformer,

the secondary side doesn't have to have any relationship

to the potential on the primary side. It's can be completely

seperate, it's a seperate winding not connected to the primary.

What and how you hook it up

determines what level anything is referenced to. In the power

transformer case, the center tap (neutral) is tied to ground.

Well, you're not seeing the problem. I wish I could draw here.

Your transformer has two wires going in, and three going out.

I don't know what primary is in my neighbor hood, let's say 2400 vac for an example. Which two wires do we use? You only have the choice of leg to leg, or leg to neutral.

Choose leg to neutral: use a 10 to 1 turns ratio, your secondary will be 240 volts line to line. Then center tap it, and you get 120 from each line to center.

BUT: why would center tap be anywhere near neutral?

The secondary centertap is the "neutral" because it carries the
imballance of the current in the secondary hot wires - the ends of the
240V winding. That is a common definition of a "neutral".

The secondary has no relationship to the primary, it is isolated from
the primary.

The secondary relationship to earth depends on how the secondary is
connected. The "neutral" (centertap) is earthed at the transformer. The
neutral is then also earthed at the building. That limits the maximum
voltage in the building with respect to the earth.



Choose leg to leg: does the same problem exist?

Once it gets into the house I understand how it works, but on the pole I'm hazy.

By the way you are dead wrong on the 6 wires thing. That part I do remember.

This web site explains it fairly well:

http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

On the wiring diagram of a telephone pole transformer on that web site:

The "black" and "red" (or L1 and L2) power supply cables that come into your house each carrying 120 VAC are connected to the low voltage side of the transformer. The white neutral wire coming into your house is connected to the center tap of the transformer.

The transformer converts 7200 VAC single phase power into 240 VAC single phase power, but the center tap is near zero voltage all the time and so you end up with "pseudo two phase 120 VAC" power. That is, single phase 240 VAC power that's been broken into two pieces, each 120 VAC, and each 180 degrees out of phase with the other.

Danny D'Amico writes:
Here is a picture of the incoming wires to my main circuit breaker:
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

If we follow those three wires *back* to the nearest transformer, what
do they look like (in terms of phase relationship to each other)?

Typical US residential distribution (many details omitted for simplification).


+------+
| |---------------- L1 (Line 1)
L1 ----| Pole | 120VAC
14KVAC | Pig |--------| 240VAC
L2 ----| | 120V |
N ----| |---------------- L2 (Line 2)
+------+ |
| |------- N (Ground_ED_ conductor)
|
gnd


Anywhere from 11,000 to 30,000 VAC, single-phase + transmission neutral,
enters the transformer which
has a primary winding and a secondary winding used to drop the
distribution voltage to the service voltage. The secondary winding
is 'center-tapped' and connected to GND. L1 and L2 are connected to the main breaker
in your service entrance panel. The N conductor from the pole pig is
connected to the grounded (neutral) bus-bar in the service entrance. The
grounding bus-bar in your service entrance is connected to a service ground
associated with the premises and that bus-bar is bonded to the grounded
bus-bar in your service entrance (and _only_ in your service entrance,
not downstream subpanels).

Note that the primary side of the pole pig is single phase for most
residential applications. The secondary side splits that single phase.

On Monday, November 18, 2013 10:08:23 AM UTC-5, TimR wrote:
On Monday, November 18, 2013 9:48:27 AM UTC-5, wrote:

Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.







All the neutrals are tied to ground. Why would you expect



the neutral on the secondary to not be at ground level?



In the strictist sense, if you take a center tap transformer,



the secondary side doesn't have to have any relationship



to the potential on the primary side. It's can be completely



seperate, it's a seperate winding not connected to the primary.



What and how you hook it up



determines what level anything is referenced to. In the power



transformer case, the center tap (neutral) is tied to ground.



Well, you're not seeing the problem. I wish I could draw here.



Your transformer has two wires going in, and three going out.



I don't know what primary is in my neighbor hood, let's say 2400 vac for an example. Which two wires do we use? You only have the choice of leg to leg, or leg to neutral.



It's one of the 3 primary phases to primary neutral.





Choose leg to neutral: use a 10 to 1 turns ratio, your secondary will be 240 volts line to line. Then center tap it, and you get 120 from each line to center.



BUT: why would center tap be anywhere near neutral?


The center tap has no relation in terms of potential
difference to anything other than the two ends of the
secondary, until you connect it to something. The
center is called the neutral and as part of the
installation, it's run to the house and also tied
to ground. Now the neutral of the transformer
is at the same potential as ground.







Choose leg to leg: does the same problem exist?



Once it gets into the house I understand how it works, but on the pole I'm hazy.



By the way you are dead wrong on the 6 wires thing. That part I do remember.

You would go from 6 wires to 3 wires in a distributions system
if and only if you were to consider the 6 wire system as the only
other alternative to deliver power. That is that you have fixed
in stone that you're to have a generator with 3 windings, delivering
3 phases via 6 wires to the load. Of course if you start with that,
then a balanced 3 phase load reduces the wires in half.

But that isn't the real world. No one would do it that way to begin
with. There are other alternatives and even a single phase system can
deliver the same power without 2X the wires. 3 phase does use less
copper and is better for other reasons as well. But it's not a miracle.
The current carrying capability of the conductors is what it is and
3 wires can't suddenly carry the same current as 6. As i recall,
the reduction in copper you get with 3 phase is around 25%.

See if this diagram helps to understand:

http://www.samlexamerica.com/support...Circuit s.pdf



---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On Monday, November 18, 2013 12:57:11 PM UTC-5, SRN wrote:
See if this diagram helps to understand:



http://www.samlexamerica.com/support...Circuit s.pdf

Good diagram. So primary is leg to ground, and secondary center tap is forced to ground. Makes sense.

Is primary ever leg to leg in residential?

On Mon, 18 Nov 2013 06:39:55 -0800 (PST), TimR
wrote:

I hate to display ignorance, and I know I should know this.

But maybe somebody can explain.

The power lines are 3 phase, meaning they're 120 degrees out of phase to each other

Yes.

allowing 3 wires to carry what 6 wires should (since they're generated by 3 sets of coils at the power plant).

Kinda sorta.

The house is fed by just one of these wires, through a center tap transformer.

Yes.

That transformer sends 3 wires to the house: Neutral, +120 volts, -120 volts.

Well... There are two AC wires that are opposite, yes. If you said
they were +120wt and -120wt, you would have a point (w being the
angular frequency, or 2*Pi*f and t=time).

Connect the two hots and you get 240, connect either hot to the neutral and you get 120.

Yes.

Your safety ground is bonded to the neutral and so you should also have 120 from any hot
wire to the ground.

Assuming no faults and ideal wires, sure.

Neutral is the center tap.

Yes. ...which is grounded.

Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side,

Yes. Almost always, though it really doesn't matter.

then the center tap should be above neutral on the secondary (house) side, right?

No. The center tap is grounded at both the transformer and the
entrance panel. It *is* ground.

Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.

It is. I don't see your problem. You described things pretty well.

On Mon, 18 Nov 2013 07:08:23 -0800 (PST), TimR
wrote:

On Monday, November 18, 2013 9:48:27 AM UTC-5, wrote:
Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.



All the neutrals are tied to ground. Why would you expect

the neutral on the secondary to not be at ground level?

In the strictist sense, if you take a center tap transformer,

the secondary side doesn't have to have any relationship

to the potential on the primary side. It's can be completely

seperate, it's a seperate winding not connected to the primary.

What and how you hook it up

determines what level anything is referenced to. In the power

transformer case, the center tap (neutral) is tied to ground.

Well, you're not seeing the problem. I wish I could draw here.

Your transformer has two wires going in, and three going out.

I don't know what primary is in my neighbor hood, let's say 2400 vac for an example. Which two wires do we use? You only have the choice of leg to leg, or leg to neutral.

Choose leg to neutral: use a 10 to 1 turns ratio, your secondary will be 240 volts line to line. Then center tap it, and you get 120 from each line to center.

Pick one. It doesn't matter.

BUT: why would center tap be anywhere near neutral?

Because that's how it's wired. You *DEFINED* it as being 0V and
connected it to ground.

Choose leg to leg: does the same problem exist?

No. There is no problem. Remember that transformers isolate. The
secondary can be at any voltage you desire it to be, regardless of the
primary (within the breakdown limits of the transformer, obviously).
You connected one of it's secondary terminals to ground, defining that
as 0V. Everything else falls out from there. You could have
connected it to 1000V, but that wouldn't be smart. ;-)

Once it gets into the house I understand how it works, but on the pole I'm hazy.

There isn't any difference how it's connected there. You may have
heard of "Delta" or "Wye" connections. Delta, connects the primary of
the transformer between phases. A "Wye" connection would be from
phase to ground. In the US, almost all loads are connected as "Wyes"
and generators as "Deltas". I'm sure there are exceptions but that's
what you'll find on your pole.

By the way you are dead wrong on the 6 wires thing. That part I do remember.

Trader is dead wrong about a lot.

On Monday, November 18, 2013 1:54:55 PM UTC-5, wrote:
On Mon, 18 Nov 2013 06:39:55 -0800 (PST), TimR

wrote:



I hate to display ignorance, and I know I should know this.



But maybe somebody can explain.



The power lines are 3 phase, meaning they're 120 degrees out of phase to each other



Yes.



allowing 3 wires to carry what 6 wires should (since they're generated by 3 sets of coils at the power plant).



Kinda sorta.



The house is fed by just one of these wires, through a center tap transformer.



Yes.



That transformer sends 3 wires to the house: Neutral, +120 volts, -120 volts.



Well... There are two AC wires that are opposite, yes. If you said

they were +120wt and -120wt, you would have a point (w being the

angular frequency, or 2*Pi*f and t=time).



And if you said they were 180 different in phase from
each other, relative to the neutral, you would also be correct.

KRW only understands opposites, not phase.




Connect the two hots and you get 240, connect either hot to the neutral and you get 120.




Yes.



Yes because the two hots are 180 deg out of phase with each
other. If they weren't you wouldn't get 240V





Your safety ground is bonded to the neutral and so you should also have 120 from any hot

wire to the ground.



Assuming no faults and ideal wires, sure.



Neutral is the center tap.



Yes. ...which is grounded.



Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side,



Yes. Almost always, though it really doesn't matter.



then the center tap should be above neutral on the secondary (house) side, right?



No. The center tap is grounded at both the transformer and the

entrance panel. It *is* ground.



The center tap is by definition the neutral. Connecting it to
ground ties it to ground potential. It's like if you had a battery
in your hand, and someone saying the negative terminal is above earth/ground
potential. It makes no sense. It has no realtion to anything when
it's not hooked up to anything. Hook the neg end of the battery to
ground and now that end is at ground potential.



Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.



It is. I don't see your problem. You described things pretty well.

Thanks everybody, that was very helpful.

On Mon, 18 Nov 2013 11:11:06 -0800 (PST), "
wrote:

On Monday, November 18, 2013 1:54:55 PM UTC-5, wrote:
On Mon, 18 Nov 2013 06:39:55 -0800 (PST), TimR

wrote:



I hate to display ignorance, and I know I should know this.



But maybe somebody can explain.



The power lines are 3 phase, meaning they're 120 degrees out of phase to each other



Yes.



allowing 3 wires to carry what 6 wires should (since they're generated by 3 sets of coils at the power plant).



Kinda sorta.



The house is fed by just one of these wires, through a center tap transformer.



Yes.



That transformer sends 3 wires to the house: Neutral, +120 volts, -120 volts.



Well... There are two AC wires that are opposite, yes. If you said

they were +120wt and -120wt, you would have a point (w being the

angular frequency, or 2*Pi*f and t=time).



And if you said they were 180 different in phase from
each other, relative to the neutral, you would also be correct.

Wrong.

KRW only understands opposites, not phase.

No, unlike the stupid lying ass, Trader, I know the difference.
more lies snipped

On Monday, November 18, 2013 4:52:51 PM UTC-5, wrote:


And if you said they were 180 different in phase from

each other, relative to the neutral, you would also be correct.



Wrong.



KRW only understands opposites, not phase.



No, unlike the stupid lying ass, Trader, I know the difference.

more lies snipped


Here, so everyone can see who's a liar and who knows what they
are talking about. From the IEEE (Institute of Electrical and
Electronic Engineers), a paper delivered at a rural electric
power conference:


"Distribution engineers have treated the standard "singlephase" distribution transformer connection as single phase because from the primary side of the transformer these connections are single phase and in the case of standard rural distribution single phase line to ground. However, with the advent of detailed circuit modeling we are beginning to see distribution modeling and analysis being accomplished past the transformer to the secondary. Which now brings into focus the reality that standard 120/240 secondary systems are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. Further, the standard 120/240 secondary is different from the two phase primary system in that the secondary phases are separated by 180 degrees instead of three phases separated by 120 degrees. "

Anyone following the discussion can read it and see that the
IEEE engineers are saying EXACTLY what I've been saying all along.
It couldn't be any more specific and on point. That IEEE paper is
100% in agreement with everything I've said. Of course krw will
snip it and ignore it, instead of learning.

On Monday, November 18, 2013 1:14:09 PM UTC-5, TimR wrote:
On Monday, November 18, 2013 12:57:11 PM UTC-5, SRN wrote:

See if this diagram helps to understand:







http://www.samlexamerica.com/support...Circuit s.pdf



Good diagram. So primary is leg to ground, and secondary center tap is forced to ground. Makes sense.



And note what else it says. It has one hot leg labled "Phase A", the other
"Phase B". That means there are two phases present. Next, look at the
note: "The phase of hot leg 2 (Phase B) is in the opposite direction,
ie 180 degrees apart from the phase of hot leg 1 (Phase A)."

Perhaps you can explain it now to krw that this document clearly
shows two phases present and that they are 180 deg out of phase
with each other. It's precisely in agreement with what I've been
saying for two days now.

On Mon, 18 Nov 2013 13:39:26 -0800 (PST), "
wrote:

On Monday, November 18, 2013 2:01:42 PM UTC-5, wrote:
On Mon, 18 Nov 2013 07:08:23 -0800 (PST), TimR

wrote:



On Monday, November 18, 2013 9:48:27 AM UTC-5, wrote:

Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.







All the neutrals are tied to ground. Why would you expect



the neutral on the secondary to not be at ground level?



In the strictist sense, if you take a center tap transformer,



the secondary side doesn't have to have any relationship



to the potential on the primary side. It's can be completely



seperate, it's a seperate winding not connected to the primary.



What and how you hook it up



determines what level anything is referenced to. In the power



transformer case, the center tap (neutral) is tied to ground.



Well, you're not seeing the problem. I wish I could draw here.



Your transformer has two wires going in, and three going out.



I don't know what primary is in my neighbor hood, let's say 2400 vac for an example. Which two wires do we use? You only have the choice of leg to leg, or leg to neutral.



Choose leg to neutral: use a 10 to 1 turns ratio, your secondary will be 240 volts line to line. Then center tap it, and you get 120 from each line to center.



Pick one. It doesn't matter.



BUT: why would center tap be anywhere near neutral?



Because that's how it's wired. You *DEFINED* it as being 0V and

connected it to ground.



Choose leg to leg: does the same problem exist?



No. There is no problem. Remember that transformers isolate. The

secondary can be at any voltage you desire it to be, regardless of the

primary (within the breakdown limits of the transformer, obviously).

You connected one of it's secondary terminals to ground, defining that

as 0V. Everything else falls out from there. You could have

connected it to 1000V, but that wouldn't be smart. ;-)



Once it gets into the house I understand how it works, but on the pole I'm hazy.



There isn't any difference how it's connected there. You may have

heard of "Delta" or "Wye" connections. Delta, connects the primary of

the transformer between phases. A "Wye" connection would be from

phase to ground. In the US, almost all loads are connected as "Wyes"

and generators as "Deltas". I'm sure there are exceptions but that's

what you'll find on your pole.



By the way you are dead wrong on the 6 wires thing. That part I do remember.



Trader is dead wrong about a lot.

So you too believe that the same amount of power that's delivered by 3 wires with 3 phase would require 6 wires, twice the amount of copper to deliver
any other way?

Stop lying, Trader, and LEARN TO READ.

snipped more of the lying sack of ****'s lies

You're as bad as Malformed.

Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is.

your confusion is becasue you don't understand how a transformer works. The pri and secondary are isolated from each other. The center tap of the sec has NO RELATIONSHIP to the primary. Think of the secondary as seperate floating power supply not related to the primary. The center tap of the secondary is neutral or ground ONLY becasue it gets connected to ground. Since it is connected to ground the two ends become +120 and -120 relative to neutral.

Mark

On Monday, November 18, 2013 4:52:51 PM UTC-5, wrote:
On Mon, 18 Nov 2013 11:11:06 -0800 (PST), "

wrote:



On Monday, November 18, 2013 1:54:55 PM UTC-5, wrote:

On Mon, 18 Nov 2013 06:39:55 -0800 (PST), TimR



wrote:







I hate to display ignorance, and I know I should know this.







But maybe somebody can explain.







The power lines are 3 phase, meaning they're 120 degrees out of phase to each other







Yes.







allowing 3 wires to carry what 6 wires should (since they're generated by 3 sets of coils at the power plant).







Kinda sorta.







The house is fed by just one of these wires, through a center tap transformer.







Yes.







That transformer sends 3 wires to the house: Neutral, +120 volts, -120 volts.







Well... There are two AC wires that are opposite, yes. If you said



they were +120wt and -120wt, you would have a point (w being the



angular frequency, or 2*Pi*f and t=time).







And if you said they were 180 different in phase from

each other, relative to the neutral, you would also be correct.



Wrong.



KRW only understands opposites, not phase.



No, unlike the stupid lying ass, Trader, I know the difference.

more lies snipped

Yes you have to snip them because they are irrefutable and
show that you;re wrong.

Typical, more name calling when you've lost an argument.
Is the IEEE lying too? Here from the peer reviewed IEEE, a paper
presented at a conference of power engineers:

http://ieeexplore.ieee.org/xpl/artic...number=4520128

"Distribution engineers have treated the standard "singlephase" distribution transformer connection as single phase because from the primary side of the transformer these connections are single phase and in the case of standard rural distribution single phase line to ground. However, with the advent of detailed circuit modeling we are beginning to see distribution modeling and analysis being accomplished past the transformer to the secondary. Which now brings into focus the reality that standard 120/240 secondary systems are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. Further, the standard 120/240 secondary is different from the two phase primary system in that the secondary phases are separated by 180 degrees instead of three phases separated by 120 degrees. "


Or how about this:

http://www.assocpower.com/index.php?Single-Phase-Power

A split-phase (240/120V) power system is a 3-wire, single-phase, mid-point neutral system, which consists of two 120V "voltage sources"; connected out-of-phase by 180 electrical degrees with a neutral connection between them.

Or this:

http://www.samlexamerica.com/support...Circuit s.pdf


"The phase of hot leg 2 (phase B) is in the opposite direction,
ie 180 deg apart from the phase of hot leg 1 (phase A)"

"The secondary of the distribution transformer has a grounded
center tap and is wound in a manner that supplies two 120V AC
phases which are 180 deg out of phase with each other (split phases)"

They even go on to talk about using a oscilloscopet to look
at them and say:

"This indicates that the two 120V AC voltages are 180 deg out of
phase"



Go ahead, snip those truths too and keep making an ass of yourself.

Mark:

I find the first diagram on this web page that was posted by SRN helpful:

http://www.samlexamerica.com/support...Circuit s.pdf

It shows the primary side of the distribution transformer connected between the 7200 VAC carried by the single phase wire and ground.

What I can't figure out here, tho, is that if the distribution transformer on the telephone pole is connected to ground, then it's connected via the ground wire that goes down the pole and is wrapped around the base of the telephone pole. So far as I know, that ground wire is not insulated, so that anyone that touches that ground wire would get a 7200 volt shock, which would surely kill them.

So, I think that wiring diagram is mostly correct, but I think there's a problem with the primary side of the transformer connected to ground via the telephone pole's grounding wire.

On Tuesday, November 19, 2013 12:03:14 PM UTC-5, nestork wrote:
;3151685 Wrote:

Here's what I'm not getting at the moment. What are the connections to

that transformer? If it is 3 phase leg to neutral on the primary side,

then the center tap should be above neutral on the secondary (house)

side, right? Which would mean that house neutral is NOT at ground level.

But I'm pretty sure it is.



your confusion is becasue you don't understand how a transformer works.

The pri and secondary are isolated from each other. The center tap of

the sec has NO RELATIONSHIP to the primary. Think of the secondary as

seperate floating power supply not related to the primary. The center

tap of the secondary is neutral or ground ONLY becasue it gets connected

to ground. Since it is connected to ground the two ends become +120 and

-120 relative to neutral.



Mark



Mark:



I find the first diagram on this web page that was posted by SRN

helpful:



http://tinyurl.com/ly24tjo





Don't let krw see that. The reference clearly says that
with a spit-phase 240v/120v service, there are two phases present
and they differ by 180 degrees. He says that just can't be.




It shows the primary side of the distribution transformer connected

between the 7200 VAC carried by the single phase wire and ground.



What I can't figure out here, tho, is that if the distribution

transformer on the telephone pole is connected to ground, then it's

connected via the ground wire that goes down the pole and is wrapped

around the base of the telephone pole. So far as I know, that ground

wire is not insulated, so that anyone that touches that ground wire

would get a 7200 volt shock, which would surely kill them.


Even if it were only connected that way, you would only get a shock
if the ground wire were broken and you grabbed the energized end.
Otherwise if you grabbed an intact wire, the only voltage present
would be whatever there is due to the small resistance of the wire,
which would result in a small voltage drop across the wire run.
The 7200 volts is across the transformer. The 25 ft of copper wire
only drops a few volts, depending on the current flowing in it and
the resistance of the wire.

Actually the transformer is typically connected to a
primary neutral. The primary neutral is in turn connected
to ground much like on the secondary (house) side. It's not
necessarily at every transformer, but periodically along
the run. Other transformers connected to the same neutral,
but from different phases, will balance out and reduce the current
flowing in the neutral.



So, I think that wiring diagram is mostly correct, but I think there's a

problem with the primary side of the transformer connected to ground via

the telephone pole's grounding wire.



Yes, IMO, they should have shown the primary connected to
a neutral, not just ground.

On Tuesday, November 19, 2013 12:03:14 PM UTC-5, nestork wrote:
;3151685 Wrote: Here's what I'm not getting at the moment. What are the connections to that transformer? If it is 3 phase leg to neutral on the primary side, then the center tap should be above neutral on the secondary (house) side, right? Which would mean that house neutral is NOT at ground level. But I'm pretty sure it is. your confusion is becasue you don't understand how a transformer works. The pri and secondary are isolated from each other. The center tap of the sec has NO RELATIONSHIP to the primary. Think of the secondary as seperate floating power supply not related to the primary. The center tap of the secondary is neutral or ground ONLY becasue it gets connected to ground. Since it is connected to ground the two ends become +120 and -120 relative to neutral. Mark Mark: I find the first diagram on this web page that was posted by SRN helpful: http://tinyurl.com/ly24tjo It shows the primary side of the distribution transformer connected between the 7200 VAC carried by the single phase wire and ground. What I can't figure out here, tho, is that if the distribution transformer on the telephone pole is connected to ground, then it's connected via the ground wire that goes down the pole and is wrapped around the base of the telephone pole. So far as I know, that ground wire is not insulated, so that anyone that touches that ground wire would get a 7200 volt shock, which would surely kill them. So, I think that wiring diagram is mostly correct, but I think there's a problem with the primary side of the transformer connected to ground via the telephone pole's grounding wire. -- nestork

OK..


in the diagram, the top of the primary is connected to 7200Volts and the bottom of the primary is connected to ground. THe voltage on the wire connected to ground is close to 0. It doesn't matter that some of the current passing through that wire started out at 7200 Volts. As long as the wire is connected to ground, it is ground. So someone can touch that wire with no problem.

BUT.. if the ground connection to the wire should come loose, then the wire will have a high voltage on it and would be dangerous, becuase it has current in it "that is trying to get to ground" and can't.

That is actually the same danger in the 3 wire dreyer circuit. The ground and neutral share the same wire and if the connection to that wire comes loose, the "ground wire" will have dangerous voltage on it.

On the pole transformer, ther bottom side of the primary coil is connected to ground, but the wire you see running down the pole is NOT the ONLY connection to ground. All the grounds in the entire distribution system are connected together so if the ground to one particular pole should come loose, the wire is still probably at ground due to all the other connections. But if I saw a loose ground wire running down a pole, I still would not want to touch it.

Mark

Mark:

But, if what you're saying is true, then there is power flowing to ground through the primary coil of every distribution transformer in the USA and Canada 24 hours per day, 7 days per week, 365 days per year.

And, with a voltage of 7200 volts driving that current, it would seem to me there would be a significant current flowing in the 40 or 50 foot cable going down from the transformer to the ground.

Why don't those cables get warm to the touch?

Is it entirely the impedance of the primary coil in the transformer? There is a 24 VAC doorbell transformer in every house in the USA and Canada. 120 Volt power is flowing through the primary coil of those transformers 24/7/365 and yet no one seems to be concerned about that power wastage.

The only thing that makes sense to me here is that the impedance of the primary coil in distribution transformers is so high that the current flow to ground is actually very small despite the driving voltage being so high.

And, I expect the same would be true for 24 VAC household transformers. That's why there's no big push on to save energy there like there is for light bulbs and appliances.

wrote in message ...
On Tuesday, November 19, 2013 12:03:14 PM UTC-5, nestork wrote:

snip

Don't let krw see that. The reference clearly says that
with a spit-phase 240v/120v service, there are two phases present
and they differ by 180 degrees. He says that just can't be.

http://www.allaboutcircuits.com/vol_2/chpt_10/1.html




more snip

They used to provide a protective cover for the transformer ground.
In the old days it was a U-shaped channel milled out of wood.

On Tuesday, November 19, 2013 8:50:23 PM UTC-5, nestork wrote:
Mark:



But, if what you're saying is true, then there is power flowing to

ground through the primary coil of every distribution transformer in the

USA and Canada 24 hours per day, 7 days per week, 365 days per year.



And, with a voltage of 7200 volts driving that current, it would seem to

me there would be a significant current flowing in the 40 or 50 foot

cable going down from the transformer to the ground.



Why don't those cables get warm to the touch?



All the power isn't flowing in those ground wires. You
typically have a neutral that is shared by multiple
transformers. Each transformer isn't connected to the
same phase, they are connected to phases in a distributed
fashion. That means that the current in the neutral is
only the unbalanced portion. If you had 3 transformers
for 3 groups of houses, each on a seperate primary phase,
with equal loads, the neutral current would sum to zero.

And then you have the neutral grounded periodically along
it's run, with a heavy, properly sized, ground wire,
capable of handling the current through it.








Is it entirely the impedance of the primary coil in the transformer?

There is a 24 VAC doorbell transformer in every house in the USA and

Canada. 120 Volt power is flowing through the primary coil of those

transformers 24/7/365 and yet no one seems to be concerned about that

power wastage. And, the only thing that makes sense here is that the

impedance of the primary coil is so high that the current flow to ground

is actually very small. Ditto for household transformers.









--

nestork

On Sun, 17 Nov 2013 19:14:56 -0700, Tony Hwang wrote:

Gnd and Neutral is connected together but
they are not same in functionality in the circuit.

For some reason, I didn't see this thread, and assumed it hadn't
posted. So I apologize for not having answered any issues.

I've learned a lot.

For example, the ground and the neutral, in my house, are connected
together in the main panel, but not in the sub panels.

I've learned the neutrals are different than grounds in other ways.
For example, they never branch (they always stay with their associated
hot wires). They only meet at the main breaker panel.

The grounds, on the other hand, go all over the place.
Plus, most of the time, they're not insulated (although they may
also be green).

On Tue, 19 Nov 2013 18:03:14 +0100, nestork wrote:

I find the first diagram on this web page that was posted by SRN
helpful:

Here's a PNG of that diagram, for reference:
http://farm8.staticflickr.com/7292/1...4ba18de1_o.png

In the dryer thread, it was noted that most USA circuit breakers
are *not* arrayed in AB-AB-AB format; but in AA-BB-AA-BB format.

I'm not sure what that means though...

On Mon, 18 Nov 2013 06:48:27 -0800, wrote:

The 6 vs three makes no sense.

Here are six distribution wires, by the way ...
http://farm8.staticflickr.com/7456/1...349dd5b6_o.gif

On Mon, 18 Nov 2013 07:08:23 -0800, TimR wrote:

By the way you are dead wrong on the 6 wires thing. That part I do remember.

I was always of the opinion that the ground was the second set of three wires.
That is, the power company grabs electrons from the ground, and then it sends
those electrons over three wires, 120 degrees out of phase, and then the
electrons return to the power company through the ground.

It's a huge loop. At least the way I understand it.

BTW, here are six wires, but they're not the same thing!
http://farm8.staticflickr.com/7456/1...349dd5b6_o.gif

On Mon, 18 Nov 2013 18:09:29 +0100, nestork wrote:

This web site explains it fairly well:
http://tinyurl.com/y4syno6

That was interesting.
Notice the 7200V primary side of the transformer didn't look
grounded in the picture (but it must have been). Right?

Also, the ground (literally) was stated as being part of the
circuit (although I would have like them to complete the circuit
at your lamp, and then *back* to the power company (via the
ground).