How does 50hz motor differ from 60hz motor?

[petrus bitbyter]

"Richard Crowley" <rcrowley7@xprt.net> schreef in bericht
news:vup2c4bgpa3831@corp.supernews.com...

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:3FEB7F8F.692BCB21@earthlink.net...
Thinker wrote:

The ONLY 3 phase motors in a home in North America are the drive
motors in you computer disks!

Maybe in a trailer park, or an older subdivision, but I have been in a
number of homes with three phase power for the air conditioning,
commercial grade kitchen equipment, and some had an elevator from the
basement, to the first and second floors. BTW, they didn't have a
personal computer in the house.

It is one thing to say that residential 3-Phase isn't common, but
quite another to make a blanket statement that it doesn't exist at all.

In 50 years up and down the west coast of the US, I have
NEVER seen 3-phase power in a residence. Even in large
multi-million dollar houses, they have conventional 240V
with grounded center-tap (120V branch circuits). Only 3-
phase I've seen was for shop/farm power.

Which only shows the world to be a little bit larger then the US west coast.
We have three phase all over the country although most common households are
connected to one phase only. The day I need more then 5kW I can ask for
three phase and I'll get it. They may even refuse to deliver more then 5kW
on a single phase as it makes load balancing more difficult. So only small
companies or offices do *not* have three phases. (That 5kW may have been
raised lately to 6 - or 7.5kW as they try to standardise the mains over
whole the EC.)

petrus


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[Richard Crowley]

"Richard Crowley" schreef ...
In 50 years up and down the west coast of the US, I have
NEVER seen 3-phase power in a residence. Even in large
multi-million dollar houses, they have conventional 240V
with grounded center-tap (120V branch circuits). Only 3-
phase I've seen was for shop/farm power.

"petrus bitbyter" wrote ...

Which only shows the world to be a little bit larger then the
US west coast. We have three phase all over the country
although most common households are connected to one
phase only.

Of course, same here (and likely most places). But I thought
we were discussing what was actually WIRED INTO THE
HOUSE. Although it is not necessarily common deep
within large residential areas to see all three phases going
down the street past your home. You can save money by not
distributing what you will likely never need in the forseeable
future.

Reminds me of the story of the power utility guy giving
his friend directions to his house. Went something like...
"Follow the 38K feeder to the fourth stepdown, turn
left and follow the 19K branch to the second crossover,
turn right, two blocks past the isolation switch, and I live
at the third transformer."

 

[Myron Samila]

Our entire residential city grid isn't even wired for 3phase here in TORONTO!! (not the
GTA, just surrounding areas).

The transformers on the street are 1phase 220V, there is not 3 phase power running on the
poles, that would have a huge effect on balancing the phases.

Comes from the step down from the transformer station as 1ph.

--
Myron Samila
Toronto, ON Canada
Samila Racing
http://204.101.251.229/myronx19
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:3FECE0E1.56F58541@earthlink.net...

Richard Crowley wrote:

In 50 years up and down the west coast of the US, I have
NEVER seen 3-phase power in a residence. Even in large
multi-million dollar houses, they have conventional 240V
with grounded center-tap (120V branch circuits). Only 3-
phase I've seen was for shop/farm power.

I readily admit its not common, but there is a home near Mt Dora,
Florida with three phase power. They also have a large Onan three phase
electric start generator. I worked on several systems there, including
cleaning the control wiring on the generator. It was owned by the family
who owned and ran Sullivan's nurseries, and Sullivan's Trailway Lounge
in Orlando. The property had three, three phase feeds. One for the main
house, and two for several eight inch wells. They also had a pair of
large diesel powered water pumps to provide water to the nursery, if the
power was out very long. No, the office wasn't in the main house. It was
on the feed to the main well pumps, quite a ways from the house. The
property was probably over 3000 acres. They had bought a number of farms
around their large home to build their nursery over the years, and they
were in the process of turning it into a golf course and a large
subdivision when the owner died.

There are other large homes in what was rural areas with three phase
at the street, and they have it in their homes. There is no problem
getting three phase service in Florida, if it passes your property. Its
up to the utility and the state regulations to decide if you can have
three phase. I can't get it here at home because this small subdivision
is on a single phase. It doesn't matter, because I don't have anything a
small three phase converter couldn't handle. The mother of a friend of
mine was a local office manager for Florida Power. She could make a
couple calls and get any answer you needed. Some were rather
interesting, compared to the way they ran things in SW Ohio.
--
Merry Christmas!

Take care, and God bless.
Michael A. Terrell
Central Florida

 

[Myron Samila]

In Canada, we step down using a three phase isolation transformer usually stepping down
from 600V


Three Phase you get a potential of 208Volts between two phases
Three Phase you get a potential of 110Volts between Ground & Hot of any phase
Single Phase you get a potential of 220Volts between Phase A and Phase B
Single Phase you get a potential of 120Volts between Ground & Hot of any phase

This is assuming a step down transformer is used for regular low voltage AC requirements.

What I meant to say about European voltage in *ALMOST* every respect is that there is a
220V+ potential between Hot and Ground, I thought that was pretty clear. Valencia Spain
is 230V, I was there recently working with a design team of a professional amplifier, then
in the UK, 240V was used as the primaries and the amp had problems, They were using a 115
O 115V transformer, it worked on 'any voltage'. Meaning, we could wire it here for 120V,
but, we were over voltage because the primaries were wired for 115V. Same with the UK,
across the two 115V primaries, instead of feeding 230V, they were feeding it 240V, blowing
up components in the amp.

--
Myron Samila
Toronto, ON Canada
Samila Racing
http://204.101.251.229/myronx19
"petrus bitbyter" <p.kralt@hccnet.nl> wrote in message
news:%NXGb.345256$G77.34901@amsnews02.chello.com...

"Michael A. Terrell" <mike.terrell@earthlink.net> schreef in bericht
news:3FEB9962.6A1E5419@earthlink.net...

No, Petrus. A typical North American home uses 240 VAC center tapped
single phase with the center tap grounded. Low power circuits are 120
VAC, while larger items are on dedicated 240 VAC circuits. If three
phase passes your house, it is to allow the utility company to select a
single phase for load balancing.

When I was a kid I grew up in a subdivision of identical houses. The
main road had three phase, with a single pair of wires going down each
street, and a power transformer for every four houses.

These days, you may find only one or two homes per transformer to
keep distribution problems from affecting as many homes. If a branch
breaks a wire and shorts a single transformer, it only affects a couple
homes. If a transformer goes bad a smaller crew can replace it, and if
a new home is built, it is easier to supply the extra electricity.


--
Merry Christmas!

Take care, and God bless.
Michael A. Terrell
Central Florida

Michael,

*That* I did not know. Thanks for the correction.

When I was a boy we had 127V. I remember the day it all has to change to
220V. We had to do without washing machine and vacuum cleaner for some days
as they has to be modified.

Some twenty years later I lived - with eight other students - in a house
that used two 127V phases to become 220V. As only one hot was monitored by
the kWh meter some students used (by that time old) 127V equipment to reduce
their costs.

Merry Christmas and a happy new year too.

petrus


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[Michael A. Terrell]

Mjolinor wrote:

Were these three phase LV feeds? I have worked a lot at FPL and never seen
an LV feed at three phase, in fact I have never seen a three phase 11kv /
110-0-110 at FPL at all either in storage, training or transformer
rebuilding yards.

First of all, are you aware that there is "Florida Power", and
"Florida Power & Light"? Two different companies. BTW, "Florida Power"
recently changed their name to "Progress Energy"


The house had a pad mounted transformer like you see for a small
strip mall. They had 120/208 three phase fed to two 200 amp panels that
I know of. The owner died a few years ago, and the property ws on the
market so I can't call and get any details. The one thing to keep in
mind is there is a different rate structure for three phase power. I ran
into a "Progress Energy" tech the other day and saw he had a pile of
current transformers in his truck I talked with him a couple minutes,
then he told me he had just replaced the C-ts at the Microdyne plant in
Ocala (I worked there till they started closing the plant) because the
meters were not showing any power use for the security lighting, and
several other small loads.

There was a small house next to CH55's (WACX, Orlando) original TV
tower in Lisbon, Florida that had three phase power as well. The
transmitter building and the house were on the same meter. "Florida
Power" contacted the station to tell them they were going to pull out
the transformers because the transmitter was no longer in service, but
changed their minds when they were informed there were several repeaters
on the site that needed air conditioned, and it used three phase. It was
cheaper to leave three phase service than replace all the three phase
equipment in the two buildings.


--
Merry Christmas!

Take care, and God bless.
Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

Myron Samila wrote:

Our entire residential city grid isn't even wired for 3phase here in TORONTO!! (not the
GTA, just surrounding areas).

The transformers on the street are 1phase 220V, there is not 3 phase power running on the
poles, that would have a huge effect on balancing the phases.

Comes from the step down from the transformer station as 1ph.

--
Myron Samila

A lot of subdivisions only have a single phase per street service
because there is no zoning for commercial service.


--
Merry Christmas!

Take care, and God bless.
Michael A. Terrell
Central Florida

 

[petrus bitbyter]

"Richard Crowley" <rcrowley7@xprt.net> schreef in bericht
news:vurb5do497ekb1@corp.supernews.com...

"Richard Crowley" schreef ...
In 50 years up and down the west coast of the US, I have
NEVER seen 3-phase power in a residence. Even in large
multi-million dollar houses, they have conventional 240V
with grounded center-tap (120V branch circuits). Only 3-
phase I've seen was for shop/farm power.


"petrus bitbyter" wrote ...
Which only shows the world to be a little bit larger then the
US west coast. We have three phase all over the country
although most common households are connected to one
phase only.

Of course, same here (and likely most places). But I thought
we were discussing what was actually WIRED INTO THE
HOUSE. Although it is not necessarily common deep
within large residential areas to see all three phases going
down the street past your home. You can save money by not
distributing what you will likely never need in the forseeable
future.

Reminds me of the story of the power utility guy giving
his friend directions to his house. Went something like...
"Follow the 38K feeder to the fourth stepdown, turn
left and follow the 19K branch to the second crossover,
turn right, two blocks past the isolation switch, and I live
at the third transformer."


Some things are really different here. I have an old radio from the fifties

that has a voltage carousel with eight different mains voltages ranging from
110V to 240V. That's where we came from. The mains were standardized to 220V
over the years but there are still local exceptions. During the last few
years the voltage was slowly raised to 230V and it is said to become 240V
over time.

Where I live (in the Netherlands) power production and distribution is done
in a three phase system. For all I know there are no air lines left except
for >100kV. So a power utility guy will get lost. Local transformers step
down from 10kV or 25kV to 400/230V. They have to service tens to hundreds of
houses. The power cable ends up in a house in a sealed black box. There one
phase is selected and connected to the kWh meter via a 25A fuse. (It may be
somewhat over 25A these days.) If you are a power user you get three phases.
For instance, one of our neighbours has an electric cooking-range and has
three phases. Commonly called "powercurrent". So if someone needs more then
the usual (~5kW) power for whatever reason they only have to rearange some
connections and replace the kWh meter for a three phase type. This way they
can do almost all control and maintenance without digging. Digging is by far
the most expensive part of the laying of the power grid so they want to do
it only once.

petrus


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[Jim Thompson]

"Richard Crowley" <rcrowley7@xprt.net> schreef in bericht
news:vurb5do497ekb1@corp.supernews.com...
"Richard Crowley" schreef ...
In 50 years up and down the west coast of the US, I have
NEVER seen 3-phase power in a residence. Even in large
multi-million dollar houses, they have conventional 240V
with grounded center-tap (120V branch circuits). Only 3-
phase I've seen was for shop/farm power.


[snip]

I had three-phase power in the first house I bought in Scottsdale,
Arizona (in 1964).

It was in an area bounded by 68th St. on the west, Scottsdale Rd.on
the east, Oak St. on the south, and Thomas Rd. on the north.

Had a nice three-phase Goettl air conditioner that purred like a
kitten ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Tomi Holger Engdahl]

"petrus bitbyter" <p.kralt@hccnet.nl> writes:

Most countries in western Europe used 220V for a long time. These days it
has been raised to 230V.

This is true.

It is said that it eventualy will become 240V.

To my knowledge there is no plans for the voltage to
become 240V in Europe. 230V is the standardized voltage
throughout Europe.

The voltage between two phases raised accordingly.

Yes. 230V from neutral to phase and 400V between phases nowadays.

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

 

[Wade Hassler]

"Myron Samila" <myronx19@no.spam.sympatico.ca> wrote in message news:<lVIGb.13621$d%1.2809129@news20.bellglobal.com>...

SNIP
I have worked on massive beam saws that cut up to 8 sheets stacked of wood per pass (CNC
X/Y), (Holz Her, Homag, Holzma), wild stuff. Massive motors, induction. They use current
sensors (PLC) to measure how dull the blade is.

SNIP

I watched one of these saws being commissioned once. The do-or-die
moment is when the saw generates its _own_ blade-guide by cutting
through the load-beam, a 4" square box channel about ten feet long.
Made a huge noise and attracted everybody in the factory, fingers in
ears and cigarettes on lips. The ceremony is especially important to
those who checked blade's axial runout.
Wade Hassler