residential wiring, panel box

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iwire

iwire

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Staff member
Location
Massachusetts
Re: residential wiring, panel box

Ron if the legs are not 180 apart the neutral would carry the total load not just the imbalance.

As Charlie pointed out if you put a scope on the two legs one is going up as the other is coming down.

We need another of Ed's great diagrams. :)
 
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ronaldrc

Senior Member
Location
Tennessee
Re: residential wiring, panel box

Bob it is one voltage rising and falling at the same time the neutral is just a center tap.

The 90 degrees in two phase is a difference in time not polarity.

I have to disagree on this one.

Ronald :)

[ December 05, 2004, 05:52 PM: Message edited by: ronaldrc ]
 
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Ed MacLaren

Senior Member
Re: residential wiring, panel box

The 90 degreees in two phase is a difference in time not polarity.
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I would have to agree with that statement. The strict definition of "phase" refers to "time" not "polarity". It is easy to confuse the two.

A two-phase system has two separate voltages (C and D in sketch) that are displaced in time 90 degrees (one quarter of a full cycle), in the same way that a three phase system has three separate voltages displaced in time by 120 degrees.

Until the wye or delta connection is made, a three phase alternator or transformer winding is simply three single phase circuits.

A and B in the sketch represent two separate voltages that are 180 degrees out of phase.

In a single phase system, one terminal is maximum positive at the same instant that the other terminal is maximum negative. There is no time difference.

The opposite polarities of a single phase voltage waveform is represented by F and G in the sketch, but both represent the voltage at the same terminal of the supply.

Ed

Phase4.gif


[ December 05, 2004, 05:54 PM: Message edited by: Ed MacLaren ]
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
Re: residential wiring, panel box

Originally posted by ronaldrc:
Bob if we would tap the secondary of the single phase 2 more times would it become 4 phase?

Ronald :)
Click to expand...
Ronald I never said we had two phase like the old two phase systems.

What I did say is the two legs are 180 degrees apart.

Bob
 
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ronaldrc

Senior Member
Location
Tennessee
Re: residential wiring, panel box

Bob where all on the same page here.As Bennie would probably say its all about words here.

If everyone here wants to call something 180 degrees out because one is positive and one is negative its OK with me.

As you know the reason we have a balance neutral is because of equal and opposing electrical forces.

Ronald :)
 
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ronaldrc

Senior Member
Location
Tennessee
Re: residential wiring, panel box

And here I tried to pick on Roger.

I wonder if Roger goes to bars if he does I bet he starts fights and leaves. :p
 
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Ed MacLaren

Senior Member
Re: residential wiring, panel box

What I did say is the two legs are 180 degrees apart.
Click to expand...
180 degrees of what? :) :)

As you know, in electrical engineering, certain "conventions" have been adopted.

The unit chosen to denote the time differences within a cycle is degrees, 360 degrees being a full cycle.

The method chosen to denote the polarity of any point in a circuit in relation to any other point are the terms "negative" and "positive".
The unit that is used to denote the amount, or the degree, that one point in a circuit is more negative or more positive than any other point, is the volt.

What is true, is that a given terminal of a voltage supply will be maximum negative 180 degrees after that same terminal was maximum positive.
In North America that would be .00833 seconds later.

Ed
 
roger

roger

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Staff member
Location
Fl
Occupation
Retired Electrician
Re: residential wiring, panel box

Hello Ronald,
And here I tried to pick on Roger.

I wonder if Roger goes to bars if he does I bet he starts fights and leaves.
Click to expand...
in my bar days I didn't start them, but I stayed for all of them, probably why I have more aches and pains than I should have. :D

Actually I was saying the same thing as Ed but with not near as good of an explanation.

I will admit I should have said 180 deg between + and - in lieu of 180 deg out (note I did not say out of PHASE ;) ).

Roger
 
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ronaldrc

Senior Member
Location
Tennessee
Re: residential wiring, panel box

Hi Roger in my bar days I never started one but I sure did leave when they started,but I still have the acnes and pains. :D
 
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