Tesla List wrote:
> > > >
> > > > Hey Fellow coilers,
> > > > Here's an easy one...I'm parallel'n some neon xformers that are all the same
> > > > model (Jeffersons) and though they are physically identical, some are out of
> > > > phase with the others and I have to cross-wire the odd ones. In other words,
> > > > instead of terminal A to A to A and B to B to B, its ABA and BAB (wish I
> > > > knew ascii art) So... on the "one" tranny that is different, do i also cross
> > > > over the secondaries? Or do they only have to be "in phase" on the primary
> > > > side? I never learned the electrical "basics", so any and all info on
> > > > transformers hows and whys will be avidly devoured. :o) Thanks in advance!
> > > >
> > > > Ken "electronics 101" Cravens
> > > >
> > > > [ You should have all the high voltage ends in phase, so that there
> > > > is a straight wire along both sides. This avoids crossing over
> > > > transformers and looks tidier. All you have to do is cross the inputs.
> > > > -- Chip ]
> > >
> > > ALL,
> > >
> > > Again, Chip remembers an earlier post of mine. Align all high voltage
> > > leads and knobs so they are "purdy" and straight! Cross over and rat's
> > > nest accordingly, to bring all in phase, all low voltage primary leads.
> > > Do this transformer by transformer (see my earlier post) never with an
> > > entire line!
> > >
> > > It appears that every day is a new day in the Neon sign Xfrmer business
> > > and the primary/secondary phasing is never done the same way twice in the
> > > same model.
> > >
> > > Finally, it is always only necessary to change only one side of any
> > > trnasformer to bring it in phase. Always fart around with the low
> > > voltage side only!!
> > How do you test the transformers to ensure that they are in phase?
> > [ Just replying here for convenience.
> > You need to make a guess at the phasing of the low voltage inputs first, and
> > just connect them as you guess.
> > Next, connect the HV leads from one side of each transformer. Then take
> > a piece of high voltage wire, hold it with a stick and masking tape, or
> > some other suitable method of insulating yourself and touch the wire to the
> > other unconnected HV lead. If you see just a tiny crackly spark, your
> > transformers are in correct phase. If you see a big bushy humming spark
> > that looks like fire, you are out of phase.
> > If in phase, you're done.
> > If out of phase, shut off the power and reverse the low voltage leads to
> > one transformer.
> > -- Chip ]
> OOOPS! I think you got it backwards! The small bushy arc means you are
> out of phase. The nice helthy arc means you are right on, and in phase!
> Richard Hull, TCBOR
> [ Well, actually, my literary skills are to blame. Here's what I meant:
> A B
> 3 3
> 3 3
> 3 3
> A' B'
> A and A' are the HV leads from xformer 1, B and B' are from xformer 2
> (the 3's are the coils) When A is connected to B and A' is connected to B'
> you'll get a big spark between A and A' (or B and B') as Richard Hull says.
> What I meant was that if you have A connected to B, and you touch A' to B'
> and there is no external connection between A and A', then you'll get a big
> bushy discharge between A' and B' when out of phase.
> If I'm still wrong, please correct me. I'll shut up, I swear :-) -- Chip]
You are correct! I just never tested for phasing this way.
*note: this is series connecting the OPEN coils (if out of phase) and
may exceed the voltage stand off of the windings to primary insultaion
when distance arced as Chip suggests. Also, the wires would need 30,000
volt insulation is using 15KV transformers. Be very careful if you opt
for this method.
The best way is to hook A to B and A' to B' and arc across the shunted
windings AB to AB'. This way the high voltage will immediately
magnetically shunt out in the insuing short to a lower, safer voltage.
Thus, no arc is a shorted condition (out of phase). A hot arc of normal
voltage (in phase).
Don't try this with non-shunted transformers! (boom!)
Richard Hull, TCBOR