|> >> Currently, the area around Vancouver BC. Other residential areas with
|> >> single-phase service: near Waterloo, Toronto, and St. Catharines
|> >> Ontario, near Montreal Quebec.
|> >> Where do you live that has full three-phase MV on top of every pole on
|> >> every street in a residential area? And three transformers on every
|> >> pole that has a transformer?
|> >The transformers aren't on every pole (every third), but the wires
|> >are. I see it all over. All you have to do is look.
|> I *have* looked where I live. I've told you what I see (a single MV
|> wire on the top of the vast majority of poles in residential areas).
If I ever get there, I'll tell you what I see, if I make it back. But
I have read some descriptions that would suggest something like 380Y/220
for three phase.
|> The next level up the distribution hierarchy is 3-phase, so 3-phase
|> lines do pass through residential areas, but only one phase is tapped
|> for the line of poles down each street or alley.
|> Again, where do you see 3-phase on every pole?
| Illinois, New York, Vermont (haven't looked here in OH).
Maybe you should. You'll find a LOT of 208Y/120, some 480Y/277 (larger
buildings), and maybe some leftover 240D/120, as well as single phase
service in 240/120. But do take your camera if you are convinced there
are some "6 star" services around.
|> Tell us some places.
|> Even when there are 3 phases, do the transformers occur in groups of 3?
And how many lugs on each are wired up? Does each transformer have the
same number of MV bushings (whether that be 1 each or 2 each)?
|> Or do you mostly get one transformer per pole, tapping only one of the
|> 3-phase MV lines? (That's what I see when there does happen to be
|> 3-phase distribution).
| One pig per pole, three wires going between poles, under the MV
That's single phase 240/120 of the Edison split phase variety. No three
phase services there.
Look for cases of THREE transformers, each with the same number of MV
bushings (either all have 1 or all have 2 each), and at least 3 LV lugs
connected on all three. If only 2 lugs are connected on all three, then
you have a wye system, usually 208Y/120 but 480Y/277 is possible (600Y/347
is very rare except in Canada). If 2 lugs are connected on 2 transformers
and 3 lugs are connected on one transformer, it is probably 240D/120.
Other possibilities also exist. Be sure to get a number of photos at many
different angles to get an unambiguous view of exactly how all the wires
are connected. If you see one with 3 lugs connected on each of 3 separate
transformers, where the middle lugs of each are connected together, and
all the outer lugs, plus the joined middle lugs as one wire, supply 7 wires
into whatever building is served, then be sure to get a LOT of photos.
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
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