Re: Explain 3 Phase

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jason Petrou by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jasonp-at-btinternet-dot-com>

> Could someone please explain 3 phase power to me and the hooks up
> configurations that go with that? i've heard of it here on the ttesla list
> and also been looking at some substations that has labels on them
> indicating 3 phase power. looking over some of the pictures of coilers
> using pigs i have seen 3 hookups on the low voltage side of the pig. i was
> wondering how these are hooked up. is the middle post ground?

3 phase is an industrial power supply that runs to large places like school,
industries and down your road. If you look at a normal outlet on a
oscilliscope you will se that it is a 50Hz sine wave. However, if you look
at a 3-phase supply on a 3 channel oscilliscope you will see that there are
3 sine waves, all offset from each other by 1/3 of a division. Thus, the
p.d. is greater because where you have a peak, you have a rise of a slope
instead of nothing. 3 phase is used to transmit power, but normal home
outlets are single phase

>also, 240 runs into the home, how do we derive only 120 from that? ive
>noticed that the 240 outlet is 4 pronged. i think i once came accross a
> post that described how to get 240 using 2 120 outlets. could i get an
> explination on how to do that?

If you are talking about a normal supply, to get 240 from a 120 outlet, you
would need a step up tranny. to do the other way round, use a step down.
simple. If you are talking about 3-phase, then the same thing, but you need
to split up the phases using a splitter (dont ask me how it works) then feed
it itno 3 trannies (or 3 separate coils on the same core) and then join it
back together (I think)

> lastly, when a person gets 3 phase power to their house, doesnt most
> equipment run on single phase? im just not fully clear on it. is there a
> second phase also? thanks

If you get 3-phase to your home, (eg. for a kiln or some seriously power
hungry device) they just run a 3-phase cable straight of the street into
your distributor board

> somewhat confused and amazed,
> fox

Have fun

Jason
"If it doesn't work, Increase the voltage!"