ATTN Mr Melrose

[leitmotif]

Phil
Here we go again.
There is a post entitled What do you call this voltage?
A week ago there was one from Maddy in Egypt

Both of these had to do with what is line to line line to center tap etc, etc, etc.

Appears to me there is much confusion regarding delta and wye and Edison 3 wire not only here is USA but throughtout the world just to make it more confusing.

I am not getting down on the guy asking the question
- I did not know enough to ask the question at one time
and I sure did not know the answer at one time either.
Someone taught me. It is a good question and deserves answer.

I would suggest a standing thread (or whatever you call it) that could be referred to so that when this question comes up again
and it will
the poster can refer to the standing thread and get his question answered with a standard common to all applications answer.

I would be more than happy to write it and have it written once and for all.

Dan Bentler

 

[tragically1969]

Its Phil Melore !!

 

[OZEE]

There are a lot of "standard questions" that could be answered that way. But it doesn't matter if nobody ever uses the search function to find them...

 

[leitmotif]

There are a lot of "standard questions" that could be answered that way. But it doesn't matter if nobody ever uses the search function to find them...

Completely agree.

Phil has
Sticky: Our Newest PLC Book... Released Today!

Under that would be another sticky:
"common electrical distribution"
(or whatevery you would call it)
You would find what I posted in "what is this voltage" -- copied below

If you are talking your house the three conductors on the service drop from the pole are Edison 3 wire.

Here is how it all works.
At the utility substation they bring in 3 phase.
Incoming is let us say 115,000 Volt phase to phase (primary distribution).
They will often reduce this to secondary distribution say 12,500 phase to phase 3 phase.

FOR COMMERCIAL
GOING OUT they go with the 12.5 to commercial at the service drop they put in a transformer 12.5 primary to say 480 secondary withe the secondary connected wye. They run a 4 conductor drop 3 hots and the common from all 3 phases (also called star point)
AT CUSTOMER SERVICE
3 phases are connected to the hots and the common to the neutral bus. The common can now be called the
neutral (GROUNDED CONDUCTOR) and is BONDED to the ground electrode system consisting of ground rods and or a water pipe. It is white or gray, at ground potential, carries current ie the imbalance between the phases.
This is also where the GROUNDING CONDUCTOR is derived. It is green, is at ground potential and normally carries no current

Both teh neutral white (GROUNDED) and ground (green) GROUNDING are often connected to the same bus ie neutral buss.

The three hots ie phases A B and C are often color coded in order Brown Orange Yellow between any two you will have 480.
Between any phase (Brown Orange or YEllow and the Neutral (GROUNDED Conductor) you will have 277.

Between neutral and ground you should have no potential but there may be some say 2 to 5 volt
and you should always have a fairly low resistance say 2 to 5 ohms.

The same is for 208 / 120 4 wire wye except the commonly colors for phases are Black Red Blue.

Now then for residential
SUBSTATION brings out two legs of 12,5 to the neighborhood. AT your house they put in the transformer with 12,5 primary and a 240 secondary. The secondary winding is centertapped (common) so that voltage from a leg of 240 to common is 120.
This is Edison 3 wire service.
AT RESIDENCE they bring in the 3 wires. Two connect to the hot bus these are often just black but we will do it right and make one black and other red. The common if done right is phase taped white at the mast head and in the panel. It is connected to the neutral bus. The neutral bus is connect to the ground grid - anything connected to neutral bus is at ground potential.
The neutral (GROUNDED) conductor is white current carrying. It will carry the imbalance of current between the two hots on a 240 load (dryer range etc) or will carry a current equal to the hot on a 120 load.
The ground (GROUNDING) green or bare or green with yellow stipe also connected to the neutral buss (in the main panel ONLY)

IN feeder panels fed by the main panel there is a separate bus for the neutral (GROUNDED current carrying white) this is floated ie not bonded to ground (ONLY in main panel) nor to the enclosure and another for the ground (GROUNDING) green etc non current carrying - this bus is bonded is bonded to the enclosure.

 

[leitmotif]

Its Phil Melore !!

I gotta keep my phases in mind or the motor goes wrong.
I gotta keep my womens names straight or life goes wrong.
Now you add another criteria!!!!
Lawzy a man's work is never done

Dan Bentler

 

[tomalbright]

After doing some reading, I am in a dilemma. I don't know if the feed going to my house (pole) is three-phase, or three single phases!

I noticed you didn't include phase descriptions in your writeup. The Wiki articles are pretty good, as well, but nothing is all in one place. Looks like a difference between household distribution, and commercial regarding phases.

Ah, more confusion...

 

[tomalbright]

I gotta keep my phases in mind or the motor goes wrong.
I gotta keep my womens names straight or life goes wrong.

All you gotta do is swap two phases.
All you gotta do is swap two wom...

Never mind.

 

[leitmotif]

After doing some reading, I am in a dilemma. I don't know if the feed going to my house (pole) is three-phase, or three single phases!

I noticed you didn't include phase descriptions in your writeup. The Wiki articles are pretty good, as well, but nothing is all in one place. Looks like a difference between household distribution, and commercial regarding phases.

Ah, more confusion...

Am I feeling twinges in my leg from you pulling on it
OR
Are you serious - my description of single phase Edison 3 wire (should I have said that??)is confusing?

Dan Bentler

 

[tomalbright]

No... I actually didn't know that home wiring was three single phases. (I only have 2 wires at home, dunno about the service feed.) Is that the same as Edison 3 wire? That's different from what I know "three phase" to be.

 

[Oakley]

Residential service is typically 2 phases (to ground).

 

[tomalbright]

I am in full agreement. I did mention "pole" in my post. Here's the article I was reading:

http://en.wikipedia.org/wiki/Single_phase_electric_power

Is that a real deal or a bunch of hooey? As far as the service provided, that is...

 

[eebads2391]

So . . . It Is two phase ! , (grin)


Slightly OT

Here in England , in factories we got three phase wired in the colour code Red Yellow Blue , with black as the neutral

In 2004 it changed to Brown Black Grey , with blue as a neutral

and when you use the three cores of a new colour coded piece of steel wire armoured cable ( colours = brown black grey )and run it as a single phase suppy , you get British electrical engineers arguing over which colour code to use

Brown as phase , grey as neutral and black as earth

OR Brown as phase , black as neutral and grey as earth

( The answer is the first one with the cores sleeved: )

grey sleeved neutral , black sleeved green and yellow )

 

[Phil Melore]

There are a lot of "standard questions" that could be answered that way. But it doesn't matter if nobody ever uses the search function to find them...

Hi Dan,

I think ozee said it best above as it applies to many topics. We'd end up with 100+ stickies...
Granted the search function does need some improvement though

Enjoy,

 

[JeffKiper]

Phil Thank you for all of your time that you devote to helping others help others.
sorry I know it is OT but I think it needs to be said evey know and then

 

[TimWilborne]

Phil, delete this if it's out of line.

Ron was big into preserving quality content. We have tried to continue this tradition on Patchn making it so users can contribute articles for this very purpose.

The feature hasn't really been advertised yet but is fully implemented
http://www.patchn.com/index.php?option=com_content&task=category&sectionid=7&id=29&Itemid=77

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