Setting Up a Pole Pig's Wiring
Updated: 07-29-06
Date: Sun, 30 Apr 2006 16:17:15 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Setting up a pole pig's wiring
Original poster: "D.C. Cox"
<resonance@jvlnet.com>
Just connect the center two connections together and float them, ie, don't
ground them on the 240 VAC side. Apply hot 1 (H1) and hot 2 (H2) across the
outer two LV bushings. Ground one side of the sec HV bushing (X1) and the
output is off the other non-grounded bushing (X2). The pig's case is grounded
and this point is also hooked directly to one of the bushings (X1).
This produces less stress on the HF sec coil as the interior side of the primary
is at X1 (grounded) potential. Less chance of corona formation in this area as
both the interior of the pri and bottom of the HF sec coil are both at ground
potential.
Dr. Resonance
>For the same reason that you don't tie the center
LV bushing of
>a pole pig to ground when using it as a Tesla
power transformer.
>
>David
Date: Sun, 30 Apr 2006 19:29:57 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: FIFTYGUY@aol.com
In a message dated 4/30/06 6:20:32 PM Eastern Daylight Time, tesla@pupman.com
writes:
>This produces less stress on the HF sec coil as
the interior side of
>the primary is at X1 (grounded) potential.
Doesn't this assume that X1 is always the connection closest to the primary
winding, or is this the convention with pole pigs? Otherwise it could make the
situation worse?
-Phil LaBudde
Date: Mon, 01 May 2006 10:25:26 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Barton B.
Anderson" <bartb@classictesla.com>
Yes, but there is no assumption. D.C. said "as the interior side of primary is
at X1 (grounded) potential". That indicates, connecting X1 to ground. That is
clear. I would however clarify ground as RF ground. I've been running this
connection on my pig ever since David discussed with me a few years ago.
This is not something that can be done with an NST system where the hv winding
is center-tap grounded. But, with a depotted NST, the center-tap to ground
connection can then be removed and run the same
way to minimize pri to sec stress.
Take care,
Bart
Tesla list wrote:
>Original poster: FIFTYGUY@aol.com
>In a message dated 4/30/06 6:20:32 PM Eastern
Daylight Time,
>tesla@pupman.com writes:
>
> >This produces less stress on the HF sec coil as
the interior side of
> >the primary is at X1 (grounded) potential.
>
> Doesn't this assume that X1 is always the
connection closest to
> the primary winding, or is this the convention
with pole pigs?
> Otherwise it could make the situation worse?
>
>-Phil LaBudde
Date: Mon, 01 May 2006 16:46:31 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: FIFTYGUY@aol.com
In a message dated 5/1/06 12:37:55 PM Eastern Daylight Time, tesla@pupman.com
writes:
>Yes, but there is no assumption. D.C. said "as
the interior side of
>primary is at X1 (grounded) potential". That
indicates, connecting X1
>to ground. That is clear.
Sorry, I'm a little slow, but that still doesn't clarify it to me. If anything,
this raises the additional issue of which end of the *primary* winding is
adjacent to the core or secondary winding. Again, unless I'm missing some
conventional labelling of pole pigs, the worst case could end up:
One end of primary (LV winding), the end furthest from core, at ground potential
Other end of primary (LV winding), the end closest to core or to the secondary's
(HV winding) HV end, at 240V One end of secondary (HV winding), the end furthest
from core, at ground potential Other end of secondary (HV winding), the end
closest to the core or to the primary's (LV winding) 240V end, at 15kV
Obviously this is the highest-stress situation, and best-case is the complete
opposite. My concern is calling the "H1" or "X1" labelled ends of the windings
the ones closest to the core or other winding. Is there some convention that pig
manufactures must follow when labelling, or should a pig owner open and verify
the connections?
>I would however clarify ground as RF ground.
Thank you for that clarification.
>I've been running this connection on my pig ever
since David
>discussed with me a few years ago.
Glad to see it's stood the test of time!
>This is not something that can be done with an
NST system where the
>hv winding is center-tap grounded. But, with a
depotted NST, the
>center-tap to ground connection can then be
removed and run the same
>way to minimize pri to sec stress.
On an (9, 12, or 15kV) NST, the interior ends of both HV windings are both
grounded to the core. Grounding one "bushing end" puts 4.5, 6, or 7.5kV stress
at the center of the HV windings to core, where there was zero stress before. If
the depotted NST HV winding fails, and the core isn't still grounded, that puts
the core floating at 4.5 - 7.5kV where it normally would be at ground. And thus
it would put an abnormal stress to the primary winding adjacent to the core. So
in that respect I don't think that connection scheme minimizes primary to
secondary stress.
-Phil LaBudde
Date: Mon, 01 May 2006 19:54:37 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Barton B.
Anderson" <bartb@classictesla.com>
Hi Phil,
Tesla list wrote:
>Original poster: FIFTYGUY@aol.com
>In a message dated 5/1/06 12:37:55 PM Eastern
Daylight Time,
>tesla@pupman.com writes:
>
> >Yes, but there is no assumption. D.C. said "as
the interior side of
> >primary is at X1 (grounded) potential". That
indicates, connecting X1
> >to ground. That is clear.
>
> Sorry, I'm a little slow, but that still
doesn't clarify it to
> me. If anything, this raises the additional
issue of which end of
> the *primary* winding is adjacent to the core or
secondary winding.
> Again, unless I'm missing some conventional
labelling of pole pigs,
> the worst case could end up:
>
>One end of primary (LV winding), the end furthest
from core, at
>ground potential
>Other end of primary (LV winding), the end
closest to core or to the
>secondary's (HV winding) HV end, at 240V
Neither end of the LV windings are at ground. They are floating. 240 Vac would
be typical in the US connecting the LV across X1 and X3. X2 is left
unconnected. I see we got our X's and H's mixed up. Thanks for being
persistent.
>One end of secondary (HV winding), the end
furthest from core, at
>ground potential
>Other end of secondary (HV winding), the end
closest to the core or
>to the primary's (LV winding) 240V end, at 15kV
Ideally, the core side should be at RF ground as this is the least stressful
situation. I connect H2 on my pig to RF ground..
>Obviously this is the highest-stress situation,
and best-case is the
>complete opposite. My concern is calling the "H1"
or "X1" labelled
>ends of the windings the ones closest to the core
or other winding.
>Is there some convention that pig manufactures
must follow when
>labelling, or should a pig owner open and verify
the connections?
Not a bad idea. Popping the lid and taking a look doesn't hurt. But there is a
standard for all distribution transformers. Looking at the transformer so that
the LV bushings are facing you, the HV bushing H1
is on the left and H2 is on the right. The LV bushing X1 is on the right. X2
(neutral) is in the center and X3 is on the left. That is the standard for a
single phase distribution transformers.
The transformer core is connected to the case. I have left the core as built and
tie RF ground to the transformer case. Mains ground stops at the control panel.
In other words, I make sure RF ground and mains ground are not connected
(otherwise, you're going to get little shocks here and there at the control
cabinet).
You're concern is certainly valid because we got our X's and H's mixed up. H2
should be at RF ground. This is the HV side closest to the core and when looking
at the LV bushings, H2 is the HV bushing on the right.
> On an (9, 12, or 15kV) NST, the interior
ends of both HV
> windings are both grounded to the core.
Grounding one "bushing end"
> puts 4.5, 6, or 7.5kV stress at the center of
the HV windings to
> core, where there was zero stress before. If the
depotted NST HV
> winding fails, and the core isn't still
grounded, that puts the
> core floating at 4.5 - 7.5kV where it normally
would be at ground.
> And thus it would put an abnormal stress to the
primary winding
> adjacent to the core. So in that respect I don't
think that
> connection scheme minimizes primary to secondary
stress.
Yes, the center of the HV side is at the core. I'm talking about "if" the NST is
unpotted, that situation could be removed. Then it could be setup just like a
distribution transformer. But I don't unpot NST's (too messy). Just a
possibility if someone wanted to go that route. The case of the NST would also
be tied to RF ground. I set my
NST under the coil and tie RF ground to the case. Mains ground is nowhere near
and only back at the control.
Hope that helps clarify.
Take care, Bart
>-Phil LaBudde
Date: Mon, 01 May 2006 22:28:18 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "D.C. Cox"
<resonance@jvlnet.com>
Sorry for the confusion. I was referring to the pri coil of the Tesla xmfr and
not the pri coil of the pole xmfr.
Pole xmfrs typically used X1 and X2 for the 220 volt side and designate H1 and
H2 on the 14.4 kV side.
We always ground one of the HV bushings (either H1 or H2) to the main 220 volt
ground. This then goes from the power supply over to the coil via standard 10
AWG THHN wire and when connecting to the spark
gap, it also connects to the inside of the pri Tesla transformer copper tubing
and also to the main RF ground. The base of Tesla coil sec also connects to the
main RF ground. We then run a 2 ought fine stranded welding cable to our main
bldg ref ground which is connected to 2 parallel external copper grounds
outside. In our museum applications we always have them install a 2 ought
welding cable from dual exterior bldg ground directly to the demo stage area
where it terminates as the base of the Tesla sec coil, ie, main RF ground.
Dr. Resonance
----- Original Message ----- From: "Tesla list" <tesla@pupman.com>
To: <tesla@pupman.com>
Sent: Monday, May 01, 2006 6:54 PM
Subject: Re: Setting up a pole pig's wiring
>Original poster: "Barton B. Anderson" <bartb@classictesla.com>
>
>Hi Phil,
>
>Tesla list wrote:
>
>>Original poster: FIFTYGUY@aol.com
>>In a message dated 5/1/06 12:37:55 PM Eastern
Daylight Time,
>>tesla@pupman.com writes:
>>
>> >Yes, but there is no assumption. D.C. said "as
the interior side of
>> >primary is at X1 (grounded) potential". That
indicates, connecting X1
>> >to ground. That is clear.
>>
>> Sorry, I'm a little slow, but that still
doesn't clarify it to
>> me. If anything, this raises the additional
issue of which end of
>> the *primary* winding is adjacent to the core
or secondary
>> winding. Again, unless I'm missing some
conventional labelling of
>> pole pigs, the worst case could end up:
>>
>>One end of primary (LV winding), the end
furthest from core, at
>>ground potential
>>Other end of primary (LV winding), the end
closest to core or to
>>the secondary's (HV winding) HV end, at 240V
>
>Neither end of the LV windings are at ground.
They are
>floating. 240 Vac would be typical in the US
connecting the LV
>across X1 and X3. X2 is left unconnected.
>I see we got our X's and H's mixed up. Thanks for
being persistent.
>
>>One end of secondary (HV winding), the end
furthest from core, at
>>ground potential
>>Other end of secondary (HV winding), the end
closest to the core or
>>to the primary's (LV winding) 240V end, at 15kV
>
>Ideally, the core side should be at RF ground as
this is the least
>stressful situation. I connect H2 on my pig to RF
ground..
>
>>Obviously this is the highest-stress situation,
and best-case is
>>the complete opposite. My concern is calling the
"H1" or "X1"
>>labelled ends of the windings the ones closest
to the core or other
>>winding. Is there some convention that pig
manufactures must follow
>>when labelling, or should a pig owner open and
verify the connections?
>
>Not a bad idea. Popping the lid and taking a look
doesn't hurt. But
>there is a standard for all distribution
transformers. Looking at
>the transformer so that the LV bushings are
facing you, the HV
>bushing H1 is on the left and H2 is on the right.
The LV bushing X1
>is on the right. X2 (neutral) is in the center
and X3 is on the
>left. That is the standard for a single phase
distribution transformers.
>
>The transformer core is connected to the case. I
have left the core
>as built and tie RF ground to the transformer
case. Mains ground
>stops at the control panel. In other words, I
make sure RF ground
>and mains ground are not connected (otherwise,
you're going to get
>little shocks here and there at the control
cabinet).
>
>You're concern is certainly valid because we got
our X's and H's
>mixed up. H2 should be at RF ground. This is the
HV side closest to
>the core and when looking at the LV bushings, H2
is the HV bushing
>on the right.
>
>
>> On an (9, 12, or 15kV) NST, the interior
ends of both HV
>> windings are both grounded to the core.
Grounding one "bushing
>> end" puts 4.5, 6, or 7.5kV stress at the center
of the HV windings
>> to core, where there was zero stress before. If
the depotted NST
>> HV winding fails, and the core isn't still
grounded, that puts the
>> core floating at 4.5 - 7.5kV where it normally
would be at ground.
>> And thus it would put an abnormal stress to the
primary winding
>> adjacent to the core. So in that respect I
don't think that
>> connection scheme minimizes primary to
secondary stress.
>
>Yes, the center of the HV side is at the core.
I'm talking about
>"if" the NST is unpotted, that situation could be
removed. Then it
>could be setup just like a distribution
transformer. But I don't
>unpot NST's (too messy). Just a possibility if
someone wanted to go
>that route. The case of the NST would also be
tied to RF ground. I
>set my NST under the coil and tie RF ground to
the case. Mains
>ground is nowhere near and only back at the
control.
>
>Hope that helps clarify.
>
>Take care,
>Bart
>
>
>>-Phil LaBudde
Date: Mon, 01 May 2006 22:28:38 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Gerry
Reynolds" <gerryreynolds@earthlink.net>
Hi Bart,
When you say H2 is the side closes to the core, are you saying the inner winding
of the H2 coil goes to the bushing. Could you describe the HV winding
geometry?? one coil or two??? and how the inner/outer windings are
connected??? My nameplate suggest two HV coils, but if this is the case, it
would make no sense to me why the inner winding of one of the coils would be
brought out to the HV bushing. Everything you have said would make perfect
sense if there was only one HV coil.
Gerry R.
>Original poster: "Barton B. Anderson" <bartb@classictesla.com>
>
>You're concern is certainly valid because we got
our X's and H's
>mixed up. H2 should be at RF ground. This is the
HV side closest to
>the core and when looking at the LV bushings, H2
is the HV bushing on the right.
Date: Mon, 01 May 2006 20:49:09 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Gerry
Reynolds" <gerryreynolds@earthlink.net>
Hi Phil,
This X1... does seem a little confusing. I looked at my PIG (2 ears) and the
two HV outputs are labeled H1 and H2 on its nameplate. I presume they connect to
the outer windings on their respective coils. The two HV coils have a common
internal node (the center tap) that is not connected to the core. If one HV
bushing is grounded,
this common node will (presumably the inner winding of each coil) will be at
7200V. If neither HV bushing is grounded, the output will be differential like
a two bushing NST. Dont know what the common node will float to, but I'm
guessing zero volts if everything is balanced.
The LV side of my pig nameplate shows two coils, where each coil is internally
wired in parallel for 120V operation or internally wired in series for 240V
operation. All LV nodes are labled as X; not X0, X1, nor X2. My pig is wired
for 240V operation where the two outer LV bushings are powered and the middle
bushing is left alone. The middle bushing is, however, connected to the common
node (center tap for 240 operation) between the two LV windings internally. The
voltage driven onto each of the outer LV bushings are normally +120Vac and
-120Vac (both hot and 180 degrees out of phase with each other). This is how
240V is delivered in the USA. Even the output of a 240V variac has both output
terminals hot. In this case, one output terminal connected to the wiper sweeps
from the -120Vac side to the +120Vac side to give you a 0 to 240Vac output
differential. The other output terminal is common with one of the input
terminals. You can NOT ground one of the LV bushings and drive 240Vac to the
other unless that is what your power source is providing. I also believe the
common opinion is to not ground the center LV bushing when driving the outer two
bushings with +120Vac and -120Vac since the two LV coils may not be balanced.
The confusion, I believe, is mostly on the HV side and whether to
ground or not ground one of the HV bushings. If someone could explain the
rational for grounding one of the HV bushings using terminology such as the
"inner winding of H1" and "outer winding of H1", and "inner winding of H2" and
"outer winding of H2", this would help. The case of the pig (core is connected
to case internally) also needs to be grounded to either mains ground or RF
ground and there will be different and legitimate opinions as to which one.
Gerry R
>Original poster: FIFTYGUY@aol.com
>In a message dated 5/1/06 12:37:55 PM Eastern
Daylight Time,
>tesla@pupman.com writes:
>
> >Yes, but there is no assumption. D.C. said "as
the interior side of
> >primary is at X1 (grounded) potential". That
indicates, connecting X1
> >to ground. That is clear.
>
> Sorry, I'm a little slow, but that still
doesn't clarify it to
> me. If anything, this raises the additional
issue of which end of
> the *primary* winding is adjacent to the core or
secondary winding.
> Again, unless I'm missing some conventional
labelling of pole pigs,
> the worst case could end up:
>
>One end of primary (LV winding), the end furthest
from core, at
>ground potential
>Other end of primary (LV winding), the end
closest to core or to the
>secondary's (HV winding) HV end, at 240V
>One end of secondary (HV winding), the end
furthest from core, at
>ground potential
>Other end of secondary (HV winding), the end
closest to the core or
>to the primary's (LV winding) 240V end, at 15kV
>
> Obviously this is the highest-stress
situation, and best-case
> is the complete opposite. My concern is calling
the "H1" or "X1"
> labelled ends of the windings the ones closest
to the core or other
> winding. Is there some convention that pig
manufactures must follow
> when labelling, or should a pig owner open and
verify the connections?
>
> >I would however clarify ground as RF ground.
>
> Thank you for that clarification.
>
> >I've been running this connection on my pig
ever since David
> >discussed with me a few years ago.
>
> Glad to see it's stood the test of time!
>
> >This is not something that can be done with an
NST system where the
> >hv winding is center-tap grounded. But, with a
depotted NST, the
> >center-tap to ground connection can then be
removed and run the same
> >way to minimize pri to sec stress.
>
> On an (9, 12, or 15kV) NST, the interior
ends of both HV
> windings are both grounded to the core.
Grounding one "bushing end"
> puts 4.5, 6, or 7.5kV stress at the center of
the HV windings to
> core, where there was zero stress before. If the
depotted NST HV
> winding fails, and the core isn't still
grounded, that puts the
> core floating at 4.5 - 7.5kV where it normally
would be at ground.
> And thus it would put an abnormal stress to the
primary winding
> adjacent to the core. So in that respect I don't
think that
> connection scheme minimizes primary to secondary
stress.
>
>-Phil LaBudde
Date: Mon, 01 May 2006 20:49:24 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: FIFTYGUY@aol.com
In a message dated 5/1/06 9:56:34 PM Eastern Daylight Time,
tesla@pupman.com writes:
>Not a bad idea. Popping the lid and taking a look
doesn't hurt. But
>there is a standard for all distribution
transformers. Looking at the
>transformer so that the LV bushings are facing
you, the HV bushing H1
>is on the left and H2 is on the right. The LV
bushing X1 is on the
>right. X2 (neutral) is in the center and X3 is on
the left. That is
>the standard for a single phase distribution
transformers.
>
>The transformer core is connected to the case. I
have left the core
>as built and tie RF ground to the transformer
case. Mains ground
>stops at the control panel. In other words, I
make sure RF ground and
>mains ground are not connected (otherwise, you're
going to get little
>shocks here and there at the control cabinet).
>
>You're concern is certainly valid because we got
our X's and H's
>mixed up. H2 should be at RF ground. This is the
HV side closest to
>the core and when looking at the LV bushings, H2
is the HV bushing on
>the right.
Thank you for your patience, Bart. The above clears it all up!
-Phil LaBudde
Date: Tue, 02 May 2006 10:29:06 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
Sounds like there isn't any consistancy with pig LV designation. Dr. R's use X1
and X2, mine uses X1 and
X3, with X2 being neutral, and Gerry stated his were all simply X.
http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
Adam
--- Tesla list <tesla@pupman.com> wrote:
> Original poster: "D.C. Cox" <resonance@jvlnet.com>
>
>
> Pole xmfrs typically used X1 and X2 for the 220
volt
> side and
> designate H1 and H2 on the 14.4 kV side.
>
>Original poster: "Gerry Reynolds"
><gerryreynolds@earthlink.net>
>
>The LV side of my pig nameplate shows two coils,
>where each coil is
>internally wired in parallel for 120V operation
or
>internally wired
>in series for 240V operation. All LV nodes are
>labled as X; not X0,
>X1, nor X2.
Date: Tue, 02 May 2006 10:29:19 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
Mine has two LV coils but only one HV coil:
http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
Does yours have a diagram showing this, or simply a description? Mine does 14.4
and 7.2 kV so two diagrams
for the LV side.
Adam
--- Tesla list <tesla@pupman.com> wrote:
> Original poster: "Gerry Reynolds"
> <gerryreynolds@earthlink.net>
>
> Hi Bart,
>
> When you say H2 is the side closes to the core,
are
> you saying the
> inner winding of the H2 coil goes to the
bushing.
> Could you describe
> the HV winding geometry?? one coil or two???
and
> how the
> inner/outer windings are connected??? My
nameplate
> suggest two HV
> coils, but if this is the case, it would make no
> sense to me why the
> inner winding of one of the coils would be
brought
> out to the HV
> bushing. Everything you have said would make
> perfect sense if there
> was only one HV coil.
>
> Gerry R.
>
> >Original poster: "Barton B. Anderson"
> <bartb@classictesla.com>
> >
> >You're concern is certainly valid because we
got
> our X's and H's
> >mixed up. H2 should be at RF ground. This is
the HV
> side closest to
> >the core and when looking at the LV bushings,
H2 is
> the HV bushing
> >on the right.
>
Date: Tue, 02 May 2006 10:29:29 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: Don Murray
<don@murrayranch.com>
Tesla list wrote:
>Original poster: "Gerry Reynolds" <gerryreynolds@earthlink.net>
My nameplate suggest two HV coils, but if
>this is the case, it would make no sense to me
why the inner winding
>of one of the coils would be brought out to the
HV
>bushing. Everything you have said would make
perfect sense if
>there was only one HV coil.
>Gerry R.
Gerry
May be dual rated 14400/7200 series or parallel those coils.
Don
Date: Tue, 02 May 2006 18:01:50 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: Don Murray
<don@murrayranch.com>
Tesla list wrote:
>Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
>Mine has two LV coils but only one HV coil:
>http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
Adam
This transformer can be used in 4 different primary distribution system, 7200V
phase to phase & 12470V phase to ground both on switch position 1 on switch
position 2 14400V phase to phase & 24940V phase to
ground. Even thou the diagram dos not show two primary coils the name plate dos
show SW POS 1 7200 and SW POS 2 14400.
On the side of the can there will be a switch could look like a pointer 4" long
pointed on one end and a screw in the middle you have to back out to rotate the
pointer 90 deg the other type will look like a knob about 3" across with a hole
in the middle unscrew this knob turn it over and the hole in the middle will fit
a switch under the knob.
>Does yours have a diagram showing this, or simply
a
>description? Mine does 14.4 and 7.2 kV so two
diagrams
>for the LV side.
Two diagrams for the LV side show series and parallel you have to remove the
lid to make this change.
This is a subtractive polarity transformer X 1,2,3 left to right additive
polarity would be X 3,2,1 left to right. To test for Polarity jumper H1 to the
left X bushing put 240V across H1 and H2 now read volts across H2 and right X
bushing if you get 264V it is additive if you get 216V it is subtractive.
Don
I fixed a typo
Date: Tue, 02 May 2006 20:40:40 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "David Rieben"
<drieben@midsouth.rr.com>
Hi Don,
Isn't the lower voltage ratings - 7200 and 14400- the "phase-to-ground" rating
and the higher voltage ratings - 12470 and 24940- the "phase-to-phase" rating?
David Rieben
----- Original Message ----- From: "Tesla list" <tesla@pupman.com>
To: <tesla@pupman.com>
Sent: Tuesday, May 02, 2006 7:01 PM
Subject: Re: Setting up a pole pig's wiring
>Original poster: Don Murray <don@murrayranch.com>
>
>
>
>Tesla list wrote:
>
>>Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
>>Mine has two LV coils but only one HV coil:
>>http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
> Adam
>
> This transformer can be used in 4 different
primary distribution
>system, 7200V phase to phase & 12470V phase to
ground both on switch
>position 1 on switch position 2 14400V phase to
phase & 24940V phase to
>ground.
> > Don
> I fixed a typo
Date: Tue, 02 May 2006 20:40:50 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Barton B.
Anderson" <bartb@classictesla.com>
Hi Gerry,
H1 is connected to a bushing and one outer hv winding. H2 is connected to a
bushing. The wire from the bushing is the common to the tap. The tap wiring (1
through 5) run down between the LV and HV windings
attaching near the bottom of the winding. There is no hv center connection to
the core. It's a single winding
which is wound around the LV winding. H1 appears to be nearest the inside of the
coil, so the H2 would end up towards the outer side nearest the outer core.
That's why I referenced H2 to RF ground. However, I doubt it makes any
difference which hv bushing runs to the core, otherwise, we probably would have
had issues in the past by now.
Two HV coils would make no sense (electrically) for single phase buck-boost
transformer (a few hundred volts). My diagram on the pig for the hv side shows a
single coil with the tap diagram in the center, however, that doesn't indicate
two coils. The taps must be on one end of the winding for the typical few
hundred volt taps.
Take care, Bart
Tesla list wrote:
>Original poster: "Gerry Reynolds" <gerryreynolds@earthlink.net>
>
>Hi Bart,
>
>When you say H2 is the side closes to the core,
are you saying the
>inner winding of the H2 coil goes to the bushing.
Could you
>describe the HV winding geometry?? one coil or
two??? and how the
>inner/outer windings are connected??? My
nameplate suggest two HV
>coils, but if this is the case, it would make no
sense to me why the
>inner winding of one of the coils would be
brought out to the HV
>bushing. Everything you have said would make
perfect sense if
>there was only one HV coil.
>
>Gerry R.
>
>
Date: Tue, 02 May 2006 20:40:59 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Barton B.
Anderson" <bartb@classictesla.com>
Hi Adam,
Regardless of what the name plate states, there is a standard. Your particular
transformer is labeled "correctly".
X1-X2-X3 with X2 being neutral. This is the standard for Additive Polarity of
which distribution pole ransformers are wired. If the pole transformer was 3
phase, you would have 3 hv terminals. In that case, H3-H2-H1 with H1 on the left
looking from the LV bushing side.
The standard relates to the direction of induced voltage, from HV winding to LV
winding. The standard is necessary to properly parallel 3-phase and 1-phase
transformers as well as connecting to existing
equipment, not to mention setting up potential and current transformers for
monitoring.
A potential transformer is different. It is Subtractive Polarity. Looking from
the LV side, H1 is on the left and H2 is on the right. Looking form the LV
side, X1 is on the left and X2 is on the right.
Note, the X numbering is opposite hand to what was mentioned earlier with the
distribution transformer (X1 on the right, etc..).
BTW, the term "polarity" refers to how the leads are brought out of the
transformer. Induce H1 to H2, and X1 to X2 would have the same polarity (same
phase). That is essentially why there is a standard.
Take care, Bart
Tesla list wrote:
>Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
>
>Sounds like there isn't any consistancy with pig
LV
>designation. Dr. R's use X1 and X2, mine uses X1
and
>X3, with X2 being neutral, and Gerry stated his
were
>all simply X.
>
>http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
>
>Adam
>
>--- Tesla list <tesla@pupman.com> wrote:
>
> > Original poster: "D.C. Cox" <resonance@jvlnet.com>
> >
> >
> > Pole xmfrs typically used X1 and X2 for the
220 volt
> > side and
> > designate H1 and H2 on the 14.4 kV side.
> >
>
> >Original poster: "Gerry Reynolds"
> ><gerryreynolds@earthlink.net>
> >
> >The LV side of my pig nameplate shows two
coils,
> >where each coil is
> >internally wired in parallel for 120V operation
or
> >internally wired
> >in series for 240V operation. All LV nodes are
> >labled as X; not X0,
> >X1, nor X2.
>
Date: Tue, 02 May 2006 20:41:18 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Barton B.
Anderson" <bartb@classictesla.com>
Mine has only one diagram. Your LV windings is certainly two for the series
(14400) or parallel (7200) operation. Your hv winding is still a single winding.
According to your spec plate, you have no tap on the case.
Take care, Bart
Tesla list wrote:
>Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
>
>Mine has two LV coils but only one HV coil:
>
>http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
>
>Does yours have a diagram showing this, or simply
a
>description? Mine does 14.4 and 7.2 kV so two
diagrams
>for the LV side.
>
>Adam
>
>--- Tesla list <tesla@pupman.com> wrote:
>
> > Original poster: "Gerry Reynolds"
> > <gerryreynolds@earthlink.net>
> >
> > Hi Bart,
> >
> > When you say H2 is the side closes to the
core, are
> > you saying the
> > inner winding of the H2 coil goes to the
bushing.
> > Could you describe
> > the HV winding geometry?? one coil or two???
and
> > how the
> > inner/outer windings are connected??? My
nameplate
> > suggest two HV
> > coils, but if this is the case, it would make
no
> > sense to me why the
> > inner winding of one of the coils would be
brought
> > out to the HV
> > bushing. Everything you have said would make
> > perfect sense if there
> > was only one HV coil.
> >
> > Gerry R.
> >
> > >Original poster: "Barton B. Anderson"
> > <bartb@classictesla.com>
> > >
> > >You're concern is certainly valid because we
got our X's and H's
> > >mixed up. H2 should be at RF ground. This is
the HV side closest to
> > >the core and when looking at the LV bushings,
H2 is the HV bushing
> > >on the right.
Date: Wed, 03 May 2006 07:11:39 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Barton B.
Anderson" <bartb@classictesla.com>
Hi Don,
Good observation. The spec plate "should" represent phase. It may or may not
represent how the terminals are configured. I see subtractive polarity is
plainly labeled on the plate. Interesting, I thought all "distribution"
transformers should be additive polarity, but apparently, that isn't so.
Thanks for pointing that out.
Take care, Bart
Tesla list wrote:
>Original poster: Don Murray <don@murrayranch.com>
>
>>ours have a diagram showing this, or simply a
>>description? Mine does 14.4 and 7.2 kV so two
diagrams
>>for the LV side.
>
>
>Two diagrams for the LV side show series and
parallel you have to
>remove the lid to make this change.
>
>This is a subtractive polarity transformer X
1,2,3 left to right
>additive polarity would be X 3,2,1 left to right.
To test for Polarity
>jumper H1 to the left X bushing put 240V across
H1 and H2 now read volts
> across H2 and right X bushing if you get 264V
it is additive if you get
> 216V it is subtractive.
>
>Don
> I fixed a typo
Date: Wed, 03 May 2006 07:11:50 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: Don Murray
<don@murrayranch.com>
Tesla list wrote:
>Original poster: "David Rieben" <drieben@midsouth.rr.com>
>Hi Don,
>Isn't the lower voltage ratings - 7200 and 14400-
the "phase-to-ground" rating
>and the higher voltage ratings - 12470 and 24940-
the "phase-to-phase" rating?
>David Rieben
Hi David
Those voltages are all phase to phase system voltages. On 12470 the phase to
ground would be 7200, and on 24940 phase to ground would be 14400.
The left diagram on the name plate shows the secondary in series; A to X1, C&B
to X2, and D to X3. The right diagram shows the secondary in parallel; A&C to X1
and B&D to X2. Low voltage is 120/240.
Don
>----- Original Message ----- From: "Tesla list"
<tesla@pupman.com>
>To: <tesla@pupman.com>
>Sent: Tuesday, May 02, 2006 7:01 PM
>Subject: Re: Setting up a pole pig's wiring
>
>>Original poster: Don Murray <don@murrayranch.com>
>>
>>Tesla list wrote:
>>
>>>Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
>>>Mine has two LV coils but only one HV coil:
>>>http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
>>
>> Adam
>>
>>This transformer can be used in 4 different
primary distribution
>>system, 7200V phase to phase & 12470V phase to
ground both on switch
>>position 1 on switch position 2 14400V phase to
phase & 24940V phase to ground.
>
>> > Don
>> I fixed a typo
>>
Date: Wed, 03 May 2006 07:11:59 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Gerry
Reynolds" <gerryreynolds@earthlink.net>
Hi Adam,
Its a diagram that is kinda funky. It shows something weird at the center coil
position and the two HV coils dont directly connect on the diagram. I've
determined hey are connected to each other in reality and not connected to core
by ohming it out.
Gerry R.
>Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
>
>Mine has two LV coils but only one HV coil:
>
>http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
>
>Does yours have a diagram showing this, or simply
a
>description? Mine does 14.4 and 7.2 kV so two
diagrams
>for the LV side.
>
>Adam
>
> > Original poster: "Gerry Reynolds"
> > My nameplate
> > suggest two HV
> > coils, but if this is the case, it would make
no
> > sense to me why the
> > inner winding of one of the coils would be
brought
> > out to the HV
> > bushing. Everything you have said would make
> > perfect sense if there
> > was only one HV coil.
> >
> > Gerry R.
> >
> > >Original poster: "Barton B. Anderson"
> > <bartb@classictesla.com>
> > >
> > >You're concern is certainly valid because we
got
> > our X's and H's
> > >mixed up. H2 should be at RF ground. This is
the HV
> > side closest to
> > >the core and when looking at the LV bushings,
H2 is
> > the HV bushing
> > >on the right
Date: Wed, 03 May 2006 07:12:10 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Gerry
Reynolds" <gerryreynolds@earthlink.net>
Hi Bart,
Im still a little confused on your meaning of "tap wiring". To me, tap means an
intermediate connection to a coil and implies there are two other possible
connections on both sides of the coil. If this is how you are using the term,
then H1 connects to one side of the HV coil and H2 connects to an intermediate
point on the coil and then
I'm wondering what the other end of the coil is connected to. I suspect you are
using "tap" to mean a connection to the inner winding of the HV coil (H2) and H1
connects to the outer winding of that coil.
I think from what you say, there is only one HV coil that is wound on top of the
LV windings. There must be insulation between the LV and HV coils that must
standoff a significant voltage, but the breakdown
from H2 to LV must be lower than from H1 to LV or core. Is this interpretation
correct???
Have people ever had problems not grounding H2, but instead leaving the HV
outputs floating???
Gerry R.
>Original poster: "Barton B. Anderson" <bartb@classictesla.com>
>
>H1 is connected to a bushing and one outer hv
winding.
>H2 is connected to a bushing. The wire from the
bushing is the
>common to the tap.
>The tap wiring (1 through 5) run down between the
LV and HV windings
>attaching near the bottom of the winding.
>There is no hv center connection to the core.
It's a single winding
>which is wound around the LV winding. H1 appears
to be nearest the
>inside of the coil, so the H2 would end up
towards the outer side
>nearest the outer core. That's why I referenced
H2 to RF ground.
>However, I doubt it makes any difference which hv
bushing runs to
>the core, otherwise, we probably would have had
issues in the past by now.
>
>Two HV coils would make no sense (electrically)
for single phase
>buck-boost transformer (a few hundred volts). My
diagram on the pig
>for the hv side shows a single coil with the tap
diagram in the
>center, however, that doesn't indicate two coils.
The taps must be
>on one end of the winding for the typical few
hundred volt taps.
>
>Take care,
>Bart
>
>Tesla list wrote:
>
>>Original poster: "Gerry Reynolds" <gerryreynolds@earthlink.net>
>>
>>Hi Bart,
>>
>>When you say H2 is the side closes to the core,
are you saying the
>>inner winding of the H2 coil goes to the
bushing. Could you
>>describe the HV winding geometry?? one coil or
two??? and how
>>the inner/outer windings are connected??? My
nameplate suggest
>>two HV coils, but if this is the case, it would
make no sense to me
>>why the inner winding of one of the coils would
be brought out to
>>the HV bushing. Everything you have said would
make perfect sense
>>if there was only one HV coil.
>>
>>Gerry R.
Date: Wed, 03 May 2006 15:53:01 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
There is only one primary (HV) coil and two secondary (LV) coils. Perhaps the
confusion is that we run them
backwards, so the pig's primary is our secondary.
http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
If it helps, the two secondary coils may be connected either in parallel or in
series, by moving a switch on
the side of the pig, for use on either 7,200 or 14,400 volts. The only
connection to the core is an optional
grounding strap, that connects the neutral bushing to the case. I don't use
that. The primary isn't
connected to anything. I run it with one bushing grounded.
Adam
--- Tesla list <tesla@pupman.com> wrote:
> Original poster: "Gerry Reynolds"
> <gerryreynolds@earthlink.net>
>
> Hi Adam,
>
> Its a diagram that is kinda funky. It shows
> something weird at the
> center coil position and the two HV coils dont
> directly connect on
> the diagram. I've determined hey are connected
to
> each other in
> reality and not connected to core by ohming it
out.
>
> Gerry R.
>
> >Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
> >
> >Mine has two LV coils but only one HV coil:
> >
>
>http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
> >
> >Does yours have a diagram showing this, or
simply a
> >description? Mine does 14.4 and 7.2 kV so two
> diagrams
> >for the LV side.
> >
> >Adam
> >
> > > Original poster: "Gerry Reynolds"
>
> > > My nameplate
> > > suggest two HV
> > > coils, but if this is the case, it would
make no
> > > sense to me why the
> > > inner winding of one of the coils would be
> brought
> > > out to the HV
> > > bushing. Everything you have said would
make
> > > perfect sense if there
> > > was only one HV coil.
> > >
> > > Gerry R.
> > >
> > > >Original poster: "Barton B. Anderson"
> > > <bartb@classictesla.com>
> > > >
> > > >You're concern is certainly valid because
we
> got
> > > our X's and H's
> > > >mixed up. H2 should be at RF ground. This
is
> the HV
> > > side closest to
> > > >the core and when looking at the LV
bushings,
> H2 is
> > > the HV bushing
> > > >on the right.
> > >
Date: Wed, 03 May 2006 19:40:35 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Barton B.
Anderson" <bartb@classictesla.com>
Hi Gerry,
The tap is a 5 position switch located on the side of the case near the top. It
switches the HV side. The switch has 1 common and then switches between 5
positions which are taps at the HV winding. Here are the tap voltages:
5 = 12540
4 = 12870
3 = 13200
2 = 13800
1 = 14400
Thus, the LV output (in normal distribution use) can be adjusted as necessary. I
of course keep the transformer tapped at position 1. This switch is just below
the top of the oil. Note the voltages and where the VH winding must be tapped to
attain those voltages.
H1 is at one end of the HV winding. H2 runs to the tap switch common. The tap
positions run down to the coil and I suspect are on the outer winding, but I
would have to disassemble to be positive (which I'm not going to do).
Yes, there are layers of insulation paper between the HV and LV coils. This is a
beefy little 10KVA unit at 1.8% impedance.
The breakdown voltage would be to full scale on the opposite end of the
non-grounded HV terminal. I've ran the pig floating for a long time and also
with H2 grounded (for a long time). No problems ever in either mode of
operation. The standoff voltage is more than enough. The oil is non-pcb and
crystal clear.
Take care,
Bart
Tesla list wrote:
>Original poster: "Gerry Reynolds" <gerryreynolds@earthlink.net>
>
>Hi Bart,
>
>Im still a little confused on your meaning of
"tap wiring". To me,
>tap means an intermediate connection to a coil
and implies there are
>two other possible connections on both sides of
the coil. If this
>is how you are using the term, then H1 connects
to one side of the
>HV coil and H2 connects to an intermediate point
on the coil and
>then I'm wondering what the other end of the coil
is connected
>to. I suspect you are using "tap" to mean a
connection to the inner
>winding of the HV coil (H2) and H1 connects to
the outer winding of that coil.
>
>I think from what you say, there is only one HV
coil that is wound
>on top of the LV windings. There must be
insulation between the LV
>and HV coils that must standoff a significant
voltage, but the
>breakdown from H2 to LV must be lower than from
H1 to LV or
>core. Is this interpretation correct???
>
>Have people ever had problems not grounding H2,
but instead leaving
>the HV outputs floating???
>
>Gerry R.
>
>
>
>>Original poster: "Barton B. Anderson" <bartb@classictesla.com>
>>
>>H1 is connected to a bushing and one outer hv
winding.
>>H2 is connected to a bushing. The wire from the
bushing is the
>>common to the tap.
>>The tap wiring (1 through 5) run down between
the LV and HV
>>windings attaching near the bottom of the
winding.
>>There is no hv center connection to the core.
It's a single winding
>>which is wound around the LV winding. H1 appears
to be nearest the
>>inside of the coil, so the H2 would end up
towards the outer side
>>nearest the outer core. That's why I referenced
H2 to RF ground.
>>However, I doubt it makes any difference which
hv bushing runs to
>>the core, otherwise, we probably would have had
issues in the past by now.
>>
>>Two HV coils would make no sense (electrically)
for single phase
>>buck-boost transformer (a few hundred volts). My
diagram on the pig
>>for the hv side shows a single coil with the tap
diagram in the
>>center, however, that doesn't indicate two
coils. The taps must be
>>on one end of the winding for the typical few
hundred volt taps.
>>
>>Take care,
>>Bart
>>
>>Tesla list wrote:
>>
>>>Original poster: "Gerry Reynolds" <gerryreynolds@earthlink.net>
>>>
>>>Hi Bart,
>>>
>>>When you say H2 is the side closes to the core,
are you saying the
>>>inner winding of the H2 coil goes to the
bushing. Could you
>>>describe the HV winding geometry?? one coil or
two??? and how
>>>the inner/outer windings are connected??? My
nameplate suggest
>>>two HV coils, but if this is the case, it would
make no sense to
>>>me why the inner winding of one of the coils
would be brought out
>>>to the HV bushing. Everything you have said
would make perfect
>>>sense if there was only one HV coil.
>>>
>>>Gerry R.
Date: Wed, 03 May 2006 19:40:55 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Barton B.
Anderson" <bartb@classictesla.com>
Here's a little document that may help. I pulled it off the internet and put it
up in a temporary directory.
http://www.classictesla.com/temp/TransfPol.pdf
Take care, Bart
Tesla list wrote:
>Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
>
>There is only one primary (HV) coil and two
secondary
>(LV) coils. Perhaps the confusion is that we run
them
>backwards, so the pig's primary is our secondary.
>
>http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
>
>If it helps, the two secondary coils may be
connected
>either in parallel or in series, by moving a
switch on
>the side of the pig, for use on either 7,200 or
14,400
>volts. The only connection to the core is an
optional
>grounding strap, that connects the neutral
bushing to
>the case. I don't use that. The primary isn't
>connected to anything. I run it with one bushing
>grounded.
>
>Adam
>
>--- Tesla list <tesla@pupman.com> wrote:
>
> > Original poster: "Gerry Reynolds"
> > <gerryreynolds@earthlink.net>
> >
> > Hi Adam,
> >
> > Its a diagram that is kinda funky. It shows
> > something weird at the
> > center coil position and the two HV coils dont
> > directly connect on
> > the diagram. I've determined hey are connected
to
> > each other in
> > reality and not connected to core by ohming it
out.
> >
> > Gerry R.
> >
> > >Original poster: Yurtle Turtle <yurtle_t@yahoo.com>
> > >
> > >Mine has two LV coils but only one HV coil:
> > >
> >
> >http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg
> > >
> > >Does yours have a diagram showing this, or
simply a
> > >description? Mine does 14.4 and 7.2 kV so two
> > diagrams
> > >for the LV side.
> > >
> > >Adam
> > >
> > > > Original poster: "Gerry Reynolds"
> >
> > > > My nameplate
> > > > suggest two HV coils, but if this is the
case, it would make no
> > > > sense to me why the inner winding of one
of the coils would be
> > brought out to
the HV
> > > > bushing. Everything you have said would
make
> > > > perfect sense if there
> > > > was only one HV coil.
> > > >
> > > > Gerry R.
> > > >
> > > > >Original poster: "Barton B. Anderson"
> > > > <bartb@classictesla.com>
> > > > >
> > > > >You're concern is certainly valid because
we got our X's and
H's
> > > > >mixed up. H2 should be at RF ground. This
is the HV side
closest to
> > > > >the core and when looking at the LV
bushings, H2 is the
HV bushing on the right.
> > > >
Date: Wed, 03 May 2006 23:41:18 -0600
From: Tesla list <tesla@pupman.com>
To: tesla@pupman.com
Subject: Re: Setting up a pole pig's wiring
Original poster: "Gerry
Reynolds" <gerryreynolds@earthlink.net>
Hi Bart,
OK, I think I understand now. My pig doesnt have this tap switch unless it is
on the inside. Also no mention of it on the diagram. You say that you suspect
the tap connections are on the outer HV winding??? If this is true, then why
ground H2. I thought the previous discussion was saying that H2 (via the tap
switch) goes to the inner windings of the HV coil that is directly on top of the
LV winding and this is why it is best to ground H2.
Gerry R.
>Original poster: "Barton B. Anderson" <bartb@classictesla.com>
>
>Hi Gerry,
>
>The tap is a 5 position switch located on the
side of the case near
>the top. It switches the HV side. The switch has
1 common and then
>switches between 5 positions which are taps at
the HV winding. Here
>are the tap voltages:
>
>5 = 12540
>4 = 12870
>3 = 13200
>2 = 13800
>1 = 14400
>
>Thus, the LV output (in normal distribution use)
can be adjusted as
>necessary. I of course keep the transformer
tapped at position 1.
>This switch is just below the top of the oil.
Note the voltages and
>where the VH winding must be tapped to attain
those voltages.
>
>H1 is at one end of the HV winding. H2 runs to
the tap switch
>common. The tap positions run down to the coil
and I suspect are on
>the outer winding, but I would have to
disassemble to be positive
>(which I'm not going to do).
>
>Yes, there are layers of insulation paper between
the HV and LV
>coils. This is a beefy little 10KVA unit at 1.8%
impedance.
>
>The breakdown voltage would be to full scale on
the opposite end of
>the non-grounded HV terminal. I've ran the pig
floating for a long
>time and also with H2 grounded (for a long time).
No problems ever
>in either mode of operation. The standoff voltage
is more than
>enough. The oil is non-pcb and crystal clear.
>
>Take care,
>Bart
>
>Tesla list wrote:
>
>>Original poster: "Gerry Reynolds" <gerryreynolds@earthlink.net>
>>
>>Hi Bart,
>>
>>Im still a little confused on your meaning of
"tap wiring". To me,
>>tap means an intermediate connection to a coil
and implies there
>>are two other possible connections on both sides
of the coil. If
>>this is how you are using the term, then H1
connects to one side of
>>the HV coil and H2 connects to an intermediate
point on the coil
>>and then I'm wondering what the other end of the
coil is connected
>>to. I suspect you are using "tap" to mean a
connection to the
>>inner winding of the HV coil (H2) and H1
connects to the outer
>>winding of that coil.
>>
>>I think from what you say, there is only one HV
coil that is wound
>>on top of the LV windings. There must be
insulation between the LV
>>and HV coils that must standoff a significant
voltage, but the
>>breakdown from H2 to LV must be lower than from
H1 to LV or
>>core. Is this interpretation correct???
>>
>>Have people ever had problems not grounding H2,
but instead leaving
>>the HV outputs floating???
>>
>>Gerry R.
>>
>>
>>
>>>Origina