Appreciate any information regarding following situation.
Bought an older house 13 years ago (central Texas). It was the
original =91ranch=92 house that owned all the acreage around that sold was
off for what is now high-density residential surrounding my few acres.
Today the city utility crew came out to change electric meter to
digital, as I watched the testing and installation of new meter, they
told me I had 3-phase and one leg was =91out=92. This surprised me as I
had no idea I had 3 phase power in residential area and have been
using rotary converters to make 3 phase (for motors) for several
years. The meter crew mentioned the need to call in others as a fuse
or breaker on a transformer must be open. They also mentioned that
since one leg of my 3 phase was out that I have likely been paying
more for my electrical bill than I should. An hour later another
(puzzled) crew came out and again verified (to their amazement) I have
a 3 phase meter and 3 phase going into wall of my house. They then
went to the pole and fixed the =91problem=92. They returned and said I had
3-phase coming off of 2 transformers on the pole and one transformer
was switched =93off=94 for some very long time. They said they fixed the
issue (took only 10 minutes), and tested the meter connections, and
confirmed that I again have 3 phase power to house=85I was astounded as
I have spent some resources on 3-phase equipment and converters for
such.
Coming out of the exterior electric meter box are 2 conduits =96 one
goes to a a more modern added breaker box that drives my machine/wood
shop, swimming pool pump, and lights for an old tennis court (This is
a =91normal=92 single phase 220 volt box), and the second =913-phase=92
conduit from meter box is going inside house wall to a throw switch
box with 3 large fuses and an old breaker box mounted above that. It
never dawned on me till today why there was 3 fuses inside the main
throw switch box.
I have a variety of 3 phase motorized equipment in my shop (which is
powered by a later-added-on breaker box that I am sure is 220 single
phase box)
I run an old metal lathe (2HP) and mill (3HP), and two 5 HP saws soon
to be hooked up and another 5 HP lathe soon to be refurbished - all
running 3 phase motors (although none run simultaneously). I have
been using (noisy) converters to run these and recently obtained 10
horse 3-phase motor and capacitors to make a larger rotary phase
converter (yet to be completed). Main point being I do use 3 phase
motors - But now, today - to my amazement =96 I find I have 3 phase
power to my house.
I have a degree from a community college in electronics =96 but it was
20 years ago and obtained just for my curiosity - so I know a little
about electronics =96 but no professional experience, and so still have
some
Questions:
What is going on here?
Have I indeed been paying too much for electric bill with one leg out
on 3-phase service?
I have read/heard somewhere in the past that 2 transformer 3-phase
isn=92t same as industrial service 3-phase =96 is there a difference
between residential 3-phase and industrial 3-phase?
Can I simply take a lines from each of the 3 fuses in the main throw
switch box and have true 3-phase to my shop (at the other side of
house ..of course)?? And would that be a better, more balanced, and
cheaper source of three phase (considering question above about =932
transformer 3-phase=94) than my rotary converters??
In the past I have had issues with lines going to this old breaker box
in that some lines some lines seem to trip breakers far too easily,
and any decent size motor in my shop dims all house lights on start,
but not the Air Conditioner. And I go through light bulbs like crazy =96
could these be manifestations of a leg being =93out=94?? (In the past I
had a visitor who worked for power company suggest I had lousy ground
connection (neutral did he mean?)..Size of service box was OK)
This house had no grounded electric receptacles. As I slowly fix this
house up - I have added new receptacles and run grounds in important
rooms (mainly a room full of computers for my business) =96=96 but I have
been running the new ground wires into the single phase (later-added
on) breaker box grounding bar =96 but the current for these lines comes
from the old 3 phase breaker box=85I am really properly grounded on
these =93updated=94 circuits=85?..Seeing that one box is single phase and
another is 3 phase..??
Further references are solicited.

Posted by Norman Webb on November 3, 2008, 6:22 pm

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See embedded answers below

tabers7823@mypacks.net wrote in message ...
Appreciate any information regarding following situation.
Bought an older house 13 years ago (central Texas). It was the
original ‘ranch’ house that owned all the acreage around that sold was
off for what is now high-density residential surrounding my few acres.
Today the city utility crew came out to change electric meter to
digital, as I watched the testing and installation of new meter, they
told me I had 3-phase and one leg was ‘out’. This surprised me as I
had no idea I had 3 phase power in residential area and have been
using rotary converters to make 3 phase (for motors) for several
years. The meter crew mentioned the need to call in others as a fuse
or breaker on a transformer must be open. They also mentioned that
since one leg of my 3 phase was out that I have likely been paying
more for my electrical bill than I should. An hour later another
(puzzled) crew came out and again verified (to their amazement) I have
a 3 phase meter and 3 phase going into wall of my house. They then
went to the pole and fixed the ‘problem’. They returned and said I had
3-phase coming off of 2 transformers on the pole and one transformer
was switched “off” for some very long time. They said they fixed the
issue (took only 10 minutes), and tested the meter connections, and
confirmed that I again have 3 phase power to house…I was astounded as
I have spent some resources on 3-phase equipment and converters for
such.
Coming out of the exterior electric meter box are 2 conduits – one
goes to a a more modern added breaker box that drives my machine/wood
shop, swimming pool pump, and lights for an old tennis court (This is
a ‘normal’ single phase 220 volt box), and the second ‘3-phase’
conduit from meter box is going inside house wall to a throw switch
box with 3 large fuses and an old breaker box mounted above that. It
never dawned on me till today why there was 3 fuses inside the main
throw switch box.
I have a variety of 3 phase motorized equipment in my shop (which is
powered by a later-added-on breaker box that I am sure is 220 single
phase box)
I run an old metal lathe (2HP) and mill (3HP), and two 5 HP saws soon
to be hooked up and another 5 HP lathe soon to be refurbished - all
running 3 phase motors (although none run simultaneously). I have
been using (noisy) converters to run these and recently obtained 10
horse 3-phase motor and capacitors to make a larger rotary phase
converter (yet to be completed). Main point being I do use 3 phase
motors - But now, today - to my amazement – I find I have 3 phase
power to my house.
I have a degree from a community college in electronics – but it was
20 years ago and obtained just for my curiosity - so I know a little
about electronics – but no professional experience, and so still have
some
Questions:
What is going on here?
Have I indeed been paying too much for electric bill with one leg out
on 3-phase service?

### Don't think so. The old three phase meter should have been measuring
power total for each phase.

I have read/heard somewhere in the past that 2 transformer 3-phase
isn’t same as industrial service 3-phase – is there a difference
between residential 3-phase and industrial 3-phase?

##### three phase is three phase. There is difference whether it is used as
a star or delta configuration. (I did electrical engineering nearly 30 years
ago ,so I am a bit rusty too)

####How many wires are on the power poles out the front? 4 wires means three
phase. I haven't heard of two trnasformer, three phase. Is it Single primary
with three secondary windings?

Can I simply take a lines from each of the 3 fuses in the main throw
switch box and have true 3-phase to my shop (at the other side of
house ..of course)??

#### yes. Better have an electrician do it.

And would that be a better, more balanced, and
cheaper source of three phase (considering question above about “2
transformer 3-phase”) than my rotary converters??

#### if we are talking single phase motor driving 3 phase generator then
direct connection has to be more efficient.

In the past I have had issues with lines going to this old breaker box
in that some lines some lines seem to trip breakers far too easily,
and any decent size motor in my shop dims all house lights on start,
but not the Air Conditioner.

#### chech the wiring size to your mains breaker and from the mains breaker
to your workshop.

And I go through light bulbs like crazy –
could these be manifestations of a leg being “out”?? (In the past I
had a visitor who worked for power company suggest I had lousy ground
connection (neutral did he mean?)..Size of service box was OK)
This house had no grounded electric receptacles. As I slowly fix this
house up - I have added new receptacles and run grounds in important
rooms (mainly a room full of computers for my business) –– but I have
been running the new ground wires into the single phase (later-added
on) breaker box grounding bar – but the current for these lines comes
from the old 3 phase breaker box…I am really properly grounded on
these “updated” circuits…?..Seeing that one box is single phase and
another is 3 phase..??

### I would get the grounding checked pretty quickly to make sure all
grounds are at the same potential. Preferably 0v.

Further references are solicited.

Posted by Norman Webb on November 3, 2008, 6:27 pm

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Norman Webb wrote in message

>I have read/heard somewhere in the past that 2 transformer 3-phase

>isn’t same as industrial service 3-phase – is there a difference

>between residential 3-phase and industrial 3-phase?

>##### three phase is three phase. There is difference whether it is used as

>a star or delta configuration. (I did electrical engineering nearly 30

years

>ago ,so I am a bit rusty too)

>####How many wires are on the power poles out the front? 4 wires means

three

>phase. I haven't heard of two trnasformer, three phase. Is it Single

primary

>with three secondary windings?

Just looked at my statement above. Three phase has each phase out of phase
by 120 deg so I can't figure out how it would work.

Posted by Pete C. on November 3, 2008, 7:04 pm

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Norman Webb wrote:

> Norman Webb wrote in message

> >

> >I have read/heard somewhere in the past that 2 transformer 3-phase

> >isn’t same as industrial service 3-phase – is there a difference

> >between residential 3-phase and industrial 3-phase?

> >

> >##### three phase is three phase. There is difference whether it is used as

> >a star or delta configuration. (I did electrical engineering nearly 30

> years

> >ago ,so I am a bit rusty too)

> >

> >####How many wires are on the power poles out the front? 4 wires means

> three

> >phase. I haven't heard of two trnasformer, three phase. Is it Single

> primary

> >with three secondary windings?

> Just looked at my statement above. Three phase has each phase out of phase

> by 120 deg so I can't figure out how it would work.

Two transformer three phase is "open delta", and it is indeed "real"
three phase.

Posted by on November 3, 2008, 8:06 pm

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> Norman Webb wrote:

> > Norman Webb wrote in message

> > >I have read/heard somewhere in the past that 2 transformer 3-phase

> > >isn=92t same as industrial service 3-phase =96 is there a difference

> > >between residential 3-phase and industrial 3-phase?

> > >##### three phase is three phase. There is difference whether it is us=

ed as

> > >a star or delta configuration. (I did electrical engineering nearly 30

> > years

> > >ago ,so I am a bit rusty too)

> > >####How many wires are on the power poles out the front? 4 wires means

> > three

> > >phase. I haven't heard of two trnasformer, three phase. Is it Single

> > primary

> > >with three secondary windings?

> > Just looked at my statement above. Three phase has each phase out of ph=

ase

> > by 120 deg so I can't figure out how it would work.

> Two transformer three phase is "open delta", and it is indeed "real"

> three phase.- Hide quoted text -

> - Show quoted text -

Thank you Pete C. - the term "Open Delta" did it for me - finding lots
of information in internet using that keyword - I get it now - thanks
for the clue...and seems it is NOT as good as a true (closed) delta -
as "open delta'' simply leaves out a winding on triangle
side..? ...but still that 3-phase setup has to better than my rotary
converters...esp considering the variety of motors I am driving (i.e.
can't balance converter specifically for one motor/load)..Is thia
what some call "farm 3-phase"...????

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