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#127197 - 05/11/01 03:20 AM Wye schematic - 3rd in the series  
Scott35  Offline

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[Linked Image]

Here's one of a 4 wire Wye, using three separate 1 phase transformers - as would be on a pole mounted transformer bank.

Note the complete difference in how the coils are wired here, as to the Delta method??

These coils [split coils] are in Parallel - so each transformer has 120 VAC output. On the Delta, each transformer's split coils are in series, so each transformer has 240 VAC output [the bottom coil is center tapped for the neutral].

Comments??

Scott SET - sorry for the text!!


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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#127198 - 05/11/01 07:39 AM Re: Wye schematic - 3rd in the series  
sparky  Offline
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Joined: Oct 2000
Posts: 5,303
Scott...
pictures! this is great!

ok, first, how do we describe this? is it a 208/120Y , 480/277Y ? do we only describe the secondary ?

[Linked Image]


#127199 - 05/11/01 02:24 PM Re: Wye schematic - 3rd in the series  
Scott35  Offline

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Steve,

For ease of discussion [not sure what that means?? [Linked Image] - joke], let's only view the secondary of this transformer.
FYI: The primary could be either Delta or Wye, it makes no difference to the secondary.

This monster is using the before mentioned single phase split coil transformers [covered in the "Delta schematic" thread].
It's using 3 separate transformers - one for each "phase".

This schematic would be how a 208Y/120 VAC 3 phase 4 wire Wye is connected - using split coil transformers having 120/240 VAC outputs.
For a 480Y/277 VAC 3 phase 4 wire Wye, the transformers might be split coil [if there's any which have 480/277 outputs], but most likely the transformers will have a single coil, which is wound for 277 VAC output.

Back to the above schematic:
The split coil secondaries on each transformer are connected in parallel, so the output voltage from each transformer coil is 120 VAC [much different than the delta one, isn't it??].
The X2/X4 ends of each transformer connect to the common jumper, whereas the X1/X3 ends run straight out - forming the output for that phase. Relative polarity in this case is setup so that each coil is in a series additive connection through the "jumper wire" and their respective X2/X4 outputs.
BTW: X1/X3 get connected together - so do X2/X4.

The "jumper wire" on this arrangement is tapped into and thus becomes the common neutral. If this was to be a 3 wire system only, no tap to the jumper is made. Tapping the jumper makes it a 4 wire [AKA multiwire] system.

Reviewing the schematic, you will see that each transformer coil's output is 120 VAC - so if you take your Wiggy and measure voltage from any one of the output phase ends to the common jumper wire, you will get a reading of 120 VAC.
Connecting the Wiggy across any two phase outputs will give a reading of 208 VAC [120 VAC x 1.732].
If you have an intellegent Octopus, it could simultainiously connect Wiggys across all of the phases, showing that theres also 208 VAC potential between L-L-L [3 phase].
If you own such Octopus, please let me know where to get one!! Needed ASAP!!

Scott SET - putting the "Wye" in "Why the heck won't he just make some sense" [Linked Image]


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#127200 - 05/11/01 02:35 PM Re: Wye schematic - 3rd in the series  
Scott35  Offline

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I forgot to mention that both schematics shown are the same - I just included them both to demonstrate how their symbols are configured.

In other words, the uppermost schematic is drawn out in the familiar Wye fashion - it's drawn with one winding at 0 degrees on the Y axis, then the other two windings are attached at 120 degree intervals from the Y axis [this is to reflect electrical degrees - somewhat..].

The drawing below it shows how everything relates to the symbolic schematic - it shows how everything gets connected exactly the same as the Wye schematic, but looks more simpler due to being an easier to read 1 line schematic.

I was hoping these methods will help persons visualise the symbolic connection easier [try to make it easier to visualise how they end up connected], which is the reason for posting both types of schematic drawings.

Scott SET - clogging your head with endless non important trivia

P.S. - had a typo to edit out!!

[This message has been edited by Scott35 (edited 05-11-2001).]


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#127201 - 05/19/01 06:44 PM Re: Wye schematic - 3rd in the series  
Scott35  Offline

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Anaheim, CA. USA
OK, the editing has been successful!! Hur-rayeeee!!!!! [Linked Image] [Linked Image] Queetohs yang fong [Linked Image] [I was watching Get Smart and someone just said that - sounded good, so I included it here].

On the subject of Get Smart, why the heck won't they just trash that Cone-Of-Silence??
That sucker is always broken!! Way too much overhead on that piece of equipment.

Oh, the schematic in this thread should make more sence now - even if the joker that posted it's message context doesn't make any [Linked Image] [this is applied to SET!!]

Any comments on these topics [schematic, or Control's reluctance in getting rid of malfunctioning security equipment]??

Scott SET


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#127202 - 05/19/01 07:05 PM Re: Wye schematic - 3rd in the series  
sparky  Offline
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Joined: Oct 2000
Posts: 5,303
if the cone of silence really worked, i'd get one for the kids, but i suspect Kaos had some input in it's design... [Linked Image]

ok, so why parrallel coils?, why not series coils???


#127203 - 05/19/01 10:20 PM Re: Wye schematic - 3rd in the series  
Scott35  Offline

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Joined: Oct 2000
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I too suspect that Kaos was involved with some level of design here, as it's operation is inverted [can't hear conversation inside but if your outside it's clear as a bell].

Plans most likely have Siegfried's PE stamp on them [Linked Image]

Having the split coils connected in parallel on this arrangement produces 120 VAC in that coil. Connecting all three individual transformers in a Wye configuration where the voltage of each transformer is 120 VAC will produce 208 VAC L-L / L-L-L, or 120 VAC to the common - this is the common method of creating a 208Y/120 VAC 3 phase 4 wire Wye system when using 3 common type 1 phase 120/240 VAC split coil transformers [Utility Companies' pole mounted xformer banks].

If the split coils were connected in series additive, the voltage of each transformer will be 240 VAC.
Now if we connect the 3 individual transformers in a Wye configuration where the voltage of each transformer is 240 VAC, the L-L / L-L-L voltage will now be 416 VAC, and of course the voltage from any one of the three transformers to the common will be 240 VAC.
This would be a 416Y/240 VAC 3 phase 4 wire Wye system.
If the common is not used, then the system would just be a 416VAC 3 phase 3 wire Wye.

BTW: Can you see how the pictorial "Y" schematic is made up of 3 individual transformers?? That's why I wanted to have the pictorial schematic drawn above the 1 line schematic - so there's a visual relationship to use.

Scott SET


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#127204 - 03/09/06 01:07 AM Re: Wye schematic - 3rd in the series  
Scott35  Offline

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***BUMP***

Scott35


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!


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