Re: Setting up a pole pig's wiring

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

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 transformers 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@xxxxxxxxx>
>
> 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@xxxxxxxxxx> wrote:
>
> > Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>
> >
> >
> > 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@xxxxxxxxxxxxx>
> >
> >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.