mivey
Senior Member
All wound together on a common core but with the center leads brought out it gets classed as a multiwinding transformer.
May I ask a question about the single vs two phase stuff
- Thread starter Russs57
- Start date
- Status
mivey
Senior Member
It is too cumbersome and disorganized. A lot of good info buried in there but too much bickering. I offered to clean it up but there were too many hurt feelings for that to happen.
I have almost all of it saved and thought of posting a scrubbed version outside the forum but I really have minimal interest. I never look at it because it is very hard to trace all the side conversations and paths and is not entertaining due to the amount of fussing.
I had several hundred posts and got caught up in the bickering as did most of the main contributors. Not our best moment on the forum.
mivey
Senior Member
Hear! Hear! The snarkiness takes all the fun out of it.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
Not for everyone, I am sorry to say.
drktmplr12
Senior Member
- Location
- South Florida
- Occupation
- Electrical Engineer
current is not the work performed. cancelled current means the sine waves are added together on the neutral and the result is zero.
Ummm (E)(I)=P therefore current is work
E*I = S. E*I*cos (pf) = P. the equation you provided does not prove current is work.
how is current the work being performed? work is power per unit time. current is most certainly proportional to work, if that's what you are meaning to say.
a series circuit isn't "created" by having balanced loads on l1-n and l2-n. there are two current phasors that meet at the neutral and add (KCL) on the path back to the center tap. when you add the current phasors and the loads are equal, they cancel because they are 180 degrees out of phase with one another and the same magnitude. the moment you have imbalanced load, the difference in magnitude will appear on the neutral.
magnetic fields are created due to movement of charge.
current is the movement of electrons in response to an electric field. work is power per unit time.
Yeah, and it's flowing because work is being done
current is flowing because the electrons forming a continuous path were subjected to an electric field. the work done depends on the current and voltage together.
let me ask the forum a question.
what if i operate a low power factor load on one leg of a split phase transformer while keeping the other leg purely resistive? how does this impact the magnetic field within the first and second halves of the secondary winding, if at all? will there be an measurable response in the opposite winding?
the current on l1-n will experience a phase shift. the current on l2-n will not. two phasors.
buffalonymann
Senior Member
- Location
- NC
we'll have to agree to disagree on this
not really
we need to agree he is right and you are wrong
EVERY ONE but you agrees
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
If I'm looking at the two current waveforms, and I want to know how much instantaneous current is flowing on the neutral at a given point in time, do I need to use phasor math or can I just use simple subtraction?
Or, for a more practical take on the question: If I'm hooking up unbalanced loads or sources to a split-phase system, based on maximum nameplate currents of the equipment, do I need to know any phasor math to size my conductors correctly? Or can I do it with elementary-school-level addition and subtraction?
drktmplr12
Senior Member
- Location
- South Florida
- Occupation
- Electrical Engineer
It requires phasor math if loads are anything other than resistive. If you can calculate the hypotenuse of a triangle you can do phasor math.
Sent from my Pixel 2 using Tapatalk
Sent from my Pixel 2 using Tapatalk
Russs57
Senior Member
- Location
- Miami, Florida, USA
- Occupation
- Maintenance Engineer
So let’s say my goal is to create a -1 reproduction of a complex wave form ( music).
If I wish to use passive devices I could use a center tapped transformer, center tapped choke, or center tapped auto transformer. Are there other choices? If I’m looking for greatest bandwidth, linearity, and constant Z....which is the best choice?
If I wish to use passive devices I could use a center tapped transformer, center tapped choke, or center tapped auto transformer. Are there other choices? If I’m looking for greatest bandwidth, linearity, and constant Z....which is the best choice?
it can be shown mathematically the neut will always be less than or equal to the largest line current
if they differ it will be between them, closer to the larger
if you use a full size neut you are good UNLESS the devices are non-linear and have high thd
someone posted an algebraic equation to calculate it
3 ph equation
just leave C out for 3W
http://forums.mikeholt.com/showthread.php?t=144531&p=1390895#post1390895
should work, have crunched the numbers for a 120/240/1 ckt
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Please do not post that thread or what you have of it.
Nobody, definitely including me personally, came of that quagmire completely clean.:ashamed1:
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
You could use one of these:
https://www.amazon.com/Shure-A95U-Transformer-Connector-Mating/dp/B0006IXJ5O
mivey
Senior Member
Yes, our behavior was quite embarrasing. You weren't modding at the time but even the mods got in on the bad behavior. Best forgotten as many hurtful words were exchanged and no need to expose old wounds.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
I agree.
mivey
Senior Member
Disagree if you like but that is how it is with utility distribution transformers.
Dual leads are brought out and the windings can be connected in series or parallel. So even if you wanted to make a weak case on tap terminology for a single lead, that is not what we have.
Some links that may help you understand:
https://www.electronics-tutorials.ws/transformer/multiple-winding-transformers.html
http://www.idc-online.com/technical...engineering/Multiple_Winding_Transformers.pdf
SG-1
Senior Member
- Location
- Ware Shoals, South Carolina
First, thanks for those links, Mivey. Great training material.
Second some things I have learned from being here all these years:
If GAR or Mivey are trying to tell you something it is best to listen, because they know.
A very esteemed member here taught me this years ago.
The general formula to determine the number of phases in any system is: 360 degrees divided by the angular displacement between the phases equals the number of phases in that system.
360/120=3phases
360/180=2phases
360/360=1phase
360/90=4phases, but since only half of the system was needed & used it became misnamed two phase. An is still causing much confusion to this date.
The beauty of a real 2 phase system is that with an angular displacement of 180 degrees the math stays on the real number line, at least for resistive loads or adding the voltages between coils.
- Status