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Re: I Need Electrical Help!

Original poster: "Eric Davidson by way of Terry Fritz <twftesla-at-uswest-dot-net>" <edavidson-at-icva.gov>

"Professor" Drew,

I would argue that making the proper connection and trying to "share" (2) 15
amp breakers to get 30 amperes, could be considerably more complex that you
may first imagine.  The first problem is phasing.  Its almost certain that
the school has 3 phase service, so you must divorce yourself from the
scenario found in your home, that being a 120-0-120 volt,  single phase
service.  Most (not all)120 volt single phase loads are fed from a 3 phase
120Y/208 volt panel (this connection allows for a grounded neutral
conductor), meaning 120 volts from any phase to neutral, and 208 volts phase
to phase. If this is indeed the case, you will never be able to get 240
volts from your wiring contraption, only 208.  As far as load sharing is
concerned, the loads would be 120 degrees apart, not 180, and you would not
be able to get (2) 120 volt circuits of opposite POLARITY (the 120 volt
circuits in a home supplied with single phase service are NOT out of phase,
or different phases, their POLARITY is opposite, a common mistake you see
alot on this list). There are other connections used in feeder panels, delta
and balanced T connections, which could supply 240 volts or (2) 120 volt
circuits of opposite polarity. Though I dont think it will blow up in your
face, I would check with the person in charge of the utilities at the school
before you try anything, especially when it is potentially dangerous, as is
a Tesla coil, and being done in a school full of curious kids. I hope this
helps. Coil safe!


> Ok,
> i know that my pt is going to suck up a lot of power, I know that it needs
> to be current limited, I know that i need a big line filter and a fast
> circuit breaker, but what are the do's and don'ts of operating a small pt
> a tesla coil.
> I have read allot about them, and i already have my control unit built and
> ready to use. I want to operate my coil on standard wall plug power, but
 > plugs can only handle 15a at the most. There are no 30a plugs anywhere in
> the school, except for in the shop for the welders. I thought about this
> problem for awhile and i think i have a solution. I haven't tried this yet
> but that's why i'm asking, so i will know if it will blow up in my face or
> not.
> My plan was to take two extension cords and clip off the female
> i will then use a multimeter to test and see if the neutrals and the
> are on the right wires. Sometimes i have noticed that the hot and the
> are mixed up on non professionally installed wall plugs. I plan on taking
> the hots and the grounds on the cords and connecting them together and
> attaching a length of 30a rated wire to them and using marettes to hold
> together. This i think will allow 15a to flow through each cord and 30a
> through the bigger cord to my 120-240v step up transformer and then to my
> pt. I will be sort of sharing two 15 amp breakers to get 30 amps.
> Is this possible or will i burn the school down? It may not be code but
 > it work? Somebody let me know before i go ahead and try it anyway!
>                                                      Up here in Canada,
>                                                      "Professor" Drew