MWBC Question - Overloading Neutral Wire? - Electrical - Page 3 - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools
Display Modes
Old 07-04-2010, 06:54 PM   #31
I=E/R
 
a7ecorsair's Avatar
 
Join Date: May 2010
Location: Minnesota
Posts: 2,052
Rewards Points: 1,000
Default


Quote:
Originally Posted by TheVillageIdiot View Post
I assume (based on your avatar) that you were an A7 pilot or support person? If so, thank you for your service. If you on the other hand you built or worked for LTV (or one of the technology providers), thank you for supporting our nations finest.
This is just a reply to this comment and not part of the discussion...
11 years maintenance on the whole A7 family (Navy) Radar, computer, Inertial Navigation, Heads-Up Display, and weapons delivery including FLIR. All at Lemoore or on a carrier! Dang, I miss those birds....
Do you have a connection the A7?

Last edited by a7ecorsair; 07-04-2010 at 06:57 PM.
a7ecorsair is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-04-2010, 06:57 PM   #32
nap
You talking to me?
 
nap's Avatar
 
Join Date: Dec 2007
Location: sw mi
Posts: 7,551
Rewards Points: 6,290
Default


Quote:
Originally Posted by a7ecorsair View Post
Dang, I miss those birds....
Hopefully the enemy said that same thing with regularity as well.
nap is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-04-2010, 07:01 PM   #33
nap
You talking to me?
 
nap's Avatar
 
Join Date: Dec 2007
Location: sw mi
Posts: 7,551
Rewards Points: 6,290
Default


Quote:
Originally Posted by Wildie View Post
I don't understand where you are finding multiple phases, when we are only dealing with one phase. (one single phase)
I would be grateful if you would explain how we get multiple phases from a single phase source.
in that particular statement, he was speaking of 3 phase power so there would be multiple phases, obviously.

as to phases in a 120/240 system; I believe it is simply a misnomer that has permeated the trade and been accepted as the term of choice. Obviously there is only 1 phase but when trying to explain, using the term phase is synonymous with leg or whatever term you happen to use. Doesn't make it the correct term, just the one that gets used.

'Tis but thy name that is my enemy;
Thou art thyself, though not a Montague.
What's Montague? it is nor hand, nor foot,
Nor arm, nor face, nor any other part
Belonging to a man. O, be some other name!
What's in a name? that which we call a rose
By any other name would smell as sweet;
So Romeo would, were he not Romeo call'd,
Retain that dear perfection which he owes
Without that title. Romeo, doff thy name,
And for that name which is no part of thee
Take all myself.
nap is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-04-2010, 07:19 PM   #34
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Rewards Points: 1,000
Default


Quote:
Originally Posted by TheVillageIdiot View Post
Something for YOU to think about!

In the US and CANADA, residential service panels are fed with (2) 120V feeds derived from a CENTER TAPPED transformer. The center tap is the NEUTRAL and the other two legs (poles) are HOT and 180 degrees OUT OF PHASE with regard to each other. That is, when one leg is at -170V the other leg is at +170V




http://www.beananimal.com/articles/e...he-reefer.aspx

Sure both poles are derived from the same sine wave, but both poles have a complete sine wave that is exactly 180 degrees opposed from the pole on the other side of the neutral. Play all the word games you want, the two sine waves derived from the transformer are 180 degrees out of phase.

You stuffed your foot in your mouth and have tried to play word games to make it look as if others were the ones who erred.
TVI. if you study this link to Wikepedia ( http://en.wikipedia.org/wiki/Three-phase ) it has an excellent article about 3 phase power.
The wave forms shown will never ever be seen on an oscilloscope, in a home that is single phase serviced.

Your diagram that you have provided, is exactly the same as the one provided to our electrical class in 1950.

What I am attempting to do, is make the point that the term ' PHASE' should never, ever be used in conjunction with single phase, residential service.

The 220 volt poles in single phase services were mistakenly called phases in early years, as the term seemed to fit, but in reality, was incorrect.
Sadly, many such as yourself, fail to grasp the significance, and unfortunately are continuing misinform those who are attempting to understand.

I'll attach a diagram of a 3 phase wave form. A wave form such as this is never to be seen in a single phased application.

Hows it feel to have both your feet in your mouth!
Attached Thumbnails
MWBC Question - Overloading Neutral Wire?-3-phase-wave.jpg  

Last edited by Wildie; 07-04-2010 at 07:21 PM. Reason: Spelling!
Wildie is offline   Reply With Quote
Old 07-04-2010, 07:23 PM   #35
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default


So how do you refer to them other then being out of phase with each other ?

Is there a correct term ?



Scuba_Dave is offline   Reply With Quote
Old 07-04-2010, 07:33 PM   #36
nap
You talking to me?
 
nap's Avatar
 
Join Date: Dec 2007
Location: sw mi
Posts: 7,551
Rewards Points: 6,290
Default


Quote:
Originally Posted by Scuba_Dave View Post
So how do you refer to them other then being out of phase with each other ?

Is there a correct term ?
yes: phase

the problem is: there is "a phase" as we see on the scopes and then there being "in or out of phase" synonymous with the term sync.

While a single phase system has only one phase, the coexisting sine waves are out or phase with each other.
nap is offline   Reply With Quote
Old 07-04-2010, 07:45 PM   #37
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default


OK, that's what I thought
I just wasn't sure if there was another term
I actually was in a big discussion about this on a Christmas site & a Mod locked the thread
So we both went over to another Christmas site where an electrician basically said the same as what you did



Scuba_Dave is offline   Reply With Quote
Old 07-04-2010, 07:56 PM   #38
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Rewards Points: 1,000
Default


Quote:
Originally Posted by nap View Post
yes: phase

the problem is: there is "a phase" as we see on the scopes and then there being "in or out of phase" synonymous with the term sync.

While a single phase system has only one phase, the coexisting sine waves are out or phase with each other.
NOT! They are exactly in step with one another!
Wildie is offline   Reply With Quote
Old 07-04-2010, 08:06 PM   #39
nap
You talking to me?
 
nap's Avatar
 
Join Date: Dec 2007
Location: sw mi
Posts: 7,551
Rewards Points: 6,290
Default


Quote:
Originally Posted by Wildie View Post
NOT! They are exactly in step with one another!




If they were in phase with each other, they would both reach their positive peak at the same time. They are in sync yet out of phase with each other.

In other words, they are in exact opposing phase relationships with each other.
nap is offline   Reply With Quote
Old 07-04-2010, 08:22 PM   #40
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default


Quote:
Originally Posted by Wildie View Post
NOT! They are exactly in step with one another!
If that were the case you would never get 240v out of them



Scuba_Dave is offline   Reply With Quote
Old 07-04-2010, 08:35 PM   #41
I=E/R
 
a7ecorsair's Avatar
 
Join Date: May 2010
Location: Minnesota
Posts: 2,052
Rewards Points: 1,000
Default


Quote:
Originally Posted by TheVillageIdiot View Post
This waveform is correct. The 120 volt waveforms are exactly opposite because the 120 volts are neutral (ground) referenced. In this type of distribution system, the one side of the transformer primary is essentially grounded just like the neutral bus. On my transformer, the one side of the primary is connect to the center tap on the secondary so it is a grounded primary driving a center tapped secondary. As in any transformer the two outside legs of the secondary are 180 degrees different.
If we cut off the secondary neutral we will have a straight 240 volt secondary. In 240 wiring we don't have or need a neutral.
The 120 volts are out of phase because we have a ground reference center tapped transformer.
a7ecorsair is offline   Reply With Quote
Old 07-04-2010, 11:21 PM   #42
I=E/R
 
a7ecorsair's Avatar
 
Join Date: May 2010
Location: Minnesota
Posts: 2,052
Rewards Points: 1,000
Default


Some more on phasing.
Phase relationships of voltage or current only have meaning when a single device makes use of them. There is no single device that requires a connection to both bus bars and the neutral to operate.
Three phase power is used to run a single device with the most common being a three phase motor and the phase relationship will determine the direction of rotation. Swap any two leads and the motor will run the other direction.
a7ecorsair is offline   Reply With Quote
Old 07-05-2010, 05:21 AM   #43
Member
 
Join Date: Mar 2007
Location: Eighty Four, Pa.15330
Posts: 1,597
Rewards Points: 1,192
Default


Quote:
Originally Posted by a7ecorsair View Post
This is just a reply to this comment and not part of the discussion...
11 years maintenance on the whole A7 family (Navy) Radar, computer, Inertial Navigation, Heads-Up Display, and weapons delivery including FLIR. All at Lemoore or on a carrier! Dang, I miss those birds....
Do you have a connection the A7?
Make mine A 6 A VMA(AW)224
bobelectric is offline   Reply With Quote
Old 07-05-2010, 08:26 AM   #44
I=E/R
 
a7ecorsair's Avatar
 
Join Date: May 2010
Location: Minnesota
Posts: 2,052
Rewards Points: 1,000
Default


Quote:
Originally Posted by bobelectric View Post
Make mine A 6 A VMA(AW)224
Ah, so we have an Intruder
a7ecorsair is offline   Reply With Quote
Old 07-05-2010, 08:41 PM   #45
Member
 
Join Date: Jul 2008
Location: Canada (s/w ON.)
Posts: 2,294
Rewards Points: 1,000
Default


Quote:
Originally Posted by Scuba_Dave View Post
If that were the case you would never get 240v out of them
Its no different than negative and positive voltages coming from a drycell battery.
Batteries don't have phases and its the same with single phase, alternating current. At any given moment in time, one pole is negative, the other is positive, then during the other half of the cycle, the opposite is true!
If you think in terms of the voltages being D.C. that is rising and falling in amplitude and then the polarity being reversed for the other half of the cycle, its easier to grasp.
Wildie is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sharing Neutrals on the same phase electro Electrical 30 08-12-2010 02:10 PM
HALP! Master/Remote Dimmer troubles! Confuserated Electrical 9 02-12-2010 03:30 PM
Question about underground wire type Tmb9862 Electrical 9 11-26-2009 10:35 AM
Ground rod or not? brotherman Electrical 30 07-15-2008 04:58 PM
MWBC neutral handifoot Electrical 4 05-12-2008 07:54 PM




Top of Page | View New Posts