Re: Ballasting a Pole Pig (Revisited)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>

If you haven't already done so, you might try simply
measuring the resistance of the pig windings, both the
HV and LV.  Off hand, I can't think of what
resistances would be "normal" for a pig the size of
yours, and it probably varies quite a bit, even for
pigs of the same rating.  Still, you should definitely
*not* see a dead short or and open circuit on the HV
side.  LV side may appear very close to a dead short,
even if it is fine, however if you have a very
accurate DMM then you may be able to measure the two
120V windings in turn (they should be the same) and
then observe that the 240V lugs present double the
resistance of the 120V lugs.

Have you popped the lid on the pig to see if there are
any signs of internal arcing?  Murky oil would
definitely be a bad sign.  If, with the HV side
unconnected, you cannot supply power to the LV side
without tripping a breaker (even with no ballast) then
something is definitely wrong.

Another thing to be mindful of with pigs is that
sometimes one of the LV lugs is not connected to
anything inside the can.  This would be the case if
the pig was used as part of a three-pack of
transformers used to supply 208V three-phase power.
In such an application, the two 120V windings are
configured in parallel rather than series.  A look
inside the can should make it obvious if this is the
case.  If it is, then you may inadvertently be putting
240V into what should be a 120V winding, or you may
effectively have one lead connected to nothing (though
the latter would certainly not explain the breaker
blowing!).

aaron

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: "C. Sibley" <a37chevy@xxxxxxxxx>
>
> I am unable to get any arc from the pig, at any
> power
> setting...
>
>
> --- Tesla list <tesla@xxxxxxxxxx> wrote:
>
>  > Original poster: "Gerry  Reynolds"
>  > <gerryreynolds@xxxxxxxxxxxxx>
>  >
>  > Hi Curt,
>  >
>  > Is the low voltage at the input of the pig with
> the
>  > JL arcing??  If
>  > so, the pig output is essentially shorted and
> will
>  > reflect to the
>  > input as a near short.   Open the JL so no arcing
>  > (no load on the PIG
>  > output) and see if the input voltage is at the
>  > variac output.    You
>  > can also remove the pig and drive just the welder
>  > with the variac and
>  > measure its primary current with various output
>  > current settings.  I
>  > bet with the welder set to max current, it will
>  > easily trip a 15A
>  > circuit breaker.  My welder draws 30 amps at its
> max
>  > setting (iirc)
>  >
>  > Gerry R.
>  >
>  > >Original poster: "C. Sibley"
> <a37chevy@xxxxxxxxx>
>  > >
>  > >David,
>  > >
>  > >I only have a 15A 220V circuit to play with, and
> am
>  > in
>  > >the process of getting the electrical upgraded.
> I
>  > can
>  > >run the setup for longer periods with the welder
>  > set
>  > >to a lower current.  But at the lower currents
> the
>  > >voltage to the pig is essentially zero.  I have
>  > >verified and cleaned all of the hookups.
>  > >
>  > >I'll try one of the other ballast methods and
> let
>  > the
>  > >list know what I find.
>  > >
>  > >Curt.
>  >
>  >
>  >
>  >
>
>
>