Transformer

Status
Not open for further replies.
hhsting said:
On the picture seems like red and black wires are secondary conductors. I dont see EGC and neutral going to secondary conduit. Should not the secondary 240/120V single phase have 2 phase, one neutral and one EGC?
Click to expand...
It's all there, primary EGC, SBJ, secondary SSBJ and GEC. As I said prior there is no neutral.
 
infinity said:
It's all there, primary EGC, SBJ, secondary SSBJ and GEC. As I said prior there is no neutral.
Click to expand...

Ok but if there were neutral It would connect where the empty not connected to anything bolt is on the transformer bus is which also has bolt connection to the green wire to EGC bar?
 
hhsting said:
Ok but if there were neutral It would connect where the empty not connected to anything bolt is on the transformer bus is which also has bolt connection to the green wire to EGC bar?
Click to expand...
Yes that bus connects the ends of the two coils together (midpoint) so the neutral would connect there just like the SBJ.
 
FWIW, there is a multiple transformer circuit that can take three phase input and deliver single phase output with the load power distributed equally over all three primary phases.
If your goal is to drive a very large single phase load in a balanced fashion from a three phase service, it is the only way to go.
 
electrofelon said:

Leyton transformer connections

Recently a discussion of the 'Leyton' transformer connection came up: http://forums.mikeholt.com/showthread.php?t=182511 The 'Leyton' connection is purported to convert a single phase load into a balanced three phase load. Hugh Leyton had previously joined the MH forum, but has not been active...
forums.mikeholt.com
Click to expand...
Most links are broken. I can't find a diagram anywhere in there.
 
I was going to comment when the Leyton connection was brought up, but electrofelon linked the thread I started on the topic.

I think I can draw a diagram from memory later.

Jon
 
This is my recollection of the Leyton connection:

leyton transformer from memory.png

It is clear that current from X1 to X0 is reflected as current on the H1 to H3 coil.

It is also clear that the current from X2 to X0 flows on both of the low voltage coils, and that the current must be exactly the same in each coil. Thus the current in the H1 to H2 coil must be the same as the H2 to H3 coil (neglecting the slight magnetizing current).

Since the current flowing from H1 to H2 is the same as the current flowing from H2 to H3, no line current is required on the H2 terminal.

Thus all three of the transformer coils are loaded, but there is single phase loading on the circuit feeding the transformer, because only H1 and H3 show line current (again, ignoring magnetizing current).

I believe that this work has only been theoretical, however in the last thread on the subject there were claims that Leyton built and measured this connection.

-Jon
 
winnie said:
This is my recollection of the Leyton connection:
Click to expand...
Back in 1978, I proposed and discussed this this connection to an engineer (Jerry Frank?) from Sorgel Electric. I was told that it works on paper and with generator windings, but it is not physically possible with standard transformer construction techniques.
 
jim dungar said:
Back in 1978, I proposed and discussed this this connection to an engineer (Jerry Frank?) from Sorgel Electric. I was told that it works on paper and with generator windings, but it is not physically possible with standard transformer construction techniques.
Click to expand...

Interesting.

My understanding is that it loads all of the coils (which means that in a generator your alternator has 2/3 of the 3 phase KVA rather than 1/3), but that it doesn't in any way 'load the third leg'. I admit, worth finding out more.

-Jon
 
winnie said:
Interesting.

My understanding is that it loads all of the coils (which means that in a generator your alternator has 2/3 of the 3 phase KVA rather than 1/3), but that it doesn't in any way 'load the third leg'. I admit, worth finding out more.

-Jon
Click to expand...
From vague memories the issue involved a transformer having primary and secondary windings on a common core while a generator had only one set of windings.
 
Status
Not open for further replies.
Top