Split phase

[Silly Sausage]

Thats exactly what you will see.

Cheers

On two channels.
I think Tony means L1 & L2 on ONE channel!

 

[Knobhead]

Thats exactly what you will see.

Cheers

Wrong!

Stop playing the smart arse. Learn about transformer phase and vector diagrams.

 

[davesparks]

Well isn't that pretty! I think it's going to peak at a bit more than 240V though.
You could easily create that trace on an oscilloscope screen, but it's not an accurate representation of what is going on.

 

[Knobhead]

I think √2 comes in to it somewhere doesn’t it Dave?

I don’t think we’re wrong, but you never know.

240V RMS = 339.41V peak→base line.

 

[ElectroChem]

240V RMS = 339.41V peak→peak.

Wouldn't the peak-to-peak be twice that Tony?

 

[Barry White]

Well isn't that pretty! I think it's going to peak at a bit more than 240V though.
You could easily create that trace on an oscilloscope screen, but it's not an accurate representation of what is going on.

was a rough representation so I used RMS voltages it was my representation of what I thought I would see would you like to draw it please

 

[Knobhead]

Wouldn't the peak-to-peak be twice that Tony?

I was altering it while you posted

 

[Knobhead]

was a rough representation so I used RMS voltages it was my representation of what I thought I would see would you like to draw it please

You used peak→base line which would give 169V RMS.

I did the drawing years ago and it's on photobucket for use elsewhere.

 

[ElectroChem]

I was altering it while you posted

Gotta be quick around here, there's always some smart-arse apprentice looking to score a point off the boss!

 

[Knobhead]

Gotta be quick around here, there's always some smart-arse apprentice looking to score a point off the boss!

True, many years ago I was the apprentice. I also got my arse kicked when I got things wrong.

I worked with some real old barstewards, learnt a lot from them though.
Up until about ten years ago I still phoned my old foreman for a chat. At 85+ he told me where to look for a fault in a 2000HP motor he’d never even seen. He was spot on the mark.

Can’t phone him now, R.I.P. Ted

 

[GEOFF S]

I think √2 comes in to it somewhere doesn’t it Dave?

I don’t think we’re wrong, but you never know.

240V RMS = 339.41V peak→base line.

Its called the crest factor, and it takes you from peak to RMS, although under certain condtions(Fault) the crest value can be greater.

Stop playing the smart arse. Learn about transformer phase and vector diagrams.

Okay, if the vectors are in phase, or 180 Degrees apart you get the same answer, though from reading J & P transformer book and other publications they state 180 degree, some were 90 degree.


Cheers

 

[Barry White]

FFs its centre tapped there would be a sine wave above and below the base line

take 2 comming in a mo

 

[GEOFF S]

Take three

For the "in phase vectors" to add we need a series connection within the Tx, this isnt the case, and it the vectors were 180 degree apart and wired in series they would subtract.

The Tx is center tapped, extract.

Center-tap transformer. The tapping point is in the exact center of the secondary winding providing a common connection for two equal but opposite secondary voltages. With the center-tap grounded, the output

V[SUB]A[/SUB]​

will be positive in nature with respect to the ground, while the voltage at the other secondary,

V[SUB]B[/SUB]​

will be negative and opposite in nature, that is they are 180[SUP]o[/SUP] electrical degrees out-of-phase with each other.

Now VA= NA/NP * VP
VB= NB/NP* VP

230 at 0 Degrees plus 230 at 180 degree = 460 Volts

 

[GEOFF S]

Take four

If we have a winding that delivers 480 volts, we earth one end(0 V and reference) and tap 1/4, 1/2 and end we would measure 120 v, 240 v and 480 v all in phase from that reference.

If we center tap the winding and earth(0 v and reference) what we would see is at the end of one winding 240 + and the other end 240 -.

So the two phases from the center tap reference are 180 degrees apart.

Cheers

 

[Knobhead]

Your just not getting this are you. Convention with transformers is governed by angular orientation of the windings not the output waveform.

I’m not continuing this further on here due to constraints imposed on me by the moderators.

some were 90 degree.

90° phase displacement. Explain for the other members.

 

[Leyland30]

This is quite simple, its classed as a single phase three wire system. In effect two phases 180 degree apart, the neutral point being at the center between the two phases.

They cant be in phase, draw out two vectors with the same direction and magnitude.

Cheers

Agree, the wave forms are 180 degree apart.

 

[Leyland30]

Jimmer, did you get it sorted.