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Default What's the largest Main Breaker available?

Most homes have a 100A to 200A main breaker. Industrial buildings and
farms often have a 300A or 400A main. Factories with lots of electrical
machinery have multiple main panels, (often 3 phase), but what is the
largest main breaker that is sold?


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Default What's the largest Main Breaker available?

On Apr 3, 7:21*pm, wrote:
Most homes have a 100A to 200A main breaker. *Industrial buildings and
farms often have a 300A or 400A main. *Factories with lots of electrical
machinery have multiple main panels, (often 3 phase), but what is the
largest main breaker that is sold?


In America
http://images.uk.ask.com/fr?q=air+bl...tart%253D0&qt=


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Default What's the largest Main Breaker available?

On Apr 3, 7:21*pm, wrote:
Most homes have a 100A to 200A main breaker. *Industrial buildings and
farms often have a 300A or 400A main. *Factories with lots of electrical
machinery have multiple main panels, (often 3 phase), but what is the
largest main breaker that is sold?


Seen operating here.
http://www.youtube.com/watch?v=NfSYQRorDgM
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Default What's the largest Main Breaker available?

On Apr 4, 6:30*am, Duesenberg wrote:
On 4/4/2012 9:20 AM, dpb wrote:



On 4/4/2012 4:55 AM, Ed Pawlowski wrote:
On Tue, 03 Apr 2012 22:07:50 -0500, wrote:
We have a 1200A in or plant, but I know they do make a 4000A. I
don't know the biggest for sure though.


Geezzzzzz as if that aint enough power!!!! I'd hate to have to pay that
electric bill. ...


All of our machines run on 440V 3ph. Keeps the wire size down.


I live it when a visitor says "wow, this is a big place, you must make
tons of money". They go into shock when I tell them the electric bill
last month was $30,000, the gas bill was $20,000 but goes up when we
turn the heat on.


Take a look at Alcoa and be thankful for small favors that it's that
small...


2010 _purchased_ electricity consumption was 55,883,973 MWhr; total
corporate direct energy consumption was 278,437,149 MWhr


--


* I read that Iceland, being a cheap source of energy because of
geothermal, was attracting aluminium plants which require massive
amounts of electricity...


Once on a visit to Alcoa aluminum plant I saw a weird long shaped
structure on the manufacturing floor, approx 20 feet long, 6 inch by
18 inch cross section. It was tapered at one end. As I stared at it,
my escort-guide told me that that item was a 'breaker' used on high
tension power lines, and a utility company had just blown one and
needed this replacement !!!! Any guess as to its current rating? Hate
to be UNDER that when it went off!
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Default What's the largest Main Breaker available?

On Apr 4, 10:20*am, Robert Macy wrote:
On Apr 4, 6:30*am, Duesenberg wrote:





On 4/4/2012 9:20 AM, dpb wrote:


On 4/4/2012 4:55 AM, Ed Pawlowski wrote:
On Tue, 03 Apr 2012 22:07:50 -0500, wrote:
We have a 1200A in or plant, but I know they do make a 4000A. I
don't know the biggest for sure though.


Geezzzzzz as if that aint enough power!!!! I'd hate to have to pay that
electric bill. ...


All of our machines run on 440V 3ph. Keeps the wire size down.


I live it when a visitor says "wow, this is a big place, you must make
tons of money". They go into shock when I tell them the electric bill
last month was $30,000, the gas bill was $20,000 but goes up when we
turn the heat on.


Take a look at Alcoa and be thankful for small favors that it's that
small...


2010 _purchased_ electricity consumption was 55,883,973 MWhr; total
corporate direct energy consumption was 278,437,149 MWhr


--


* I read that Iceland, being a cheap source of energy because of
geothermal, was attracting aluminium plants which require massive
amounts of electricity...


Once on a visit to Alcoa aluminum plant I saw a weird long shaped
structure on the manufacturing floor, approx 20 feet long, 6 inch by
18 inch cross section. It was tapered at one end. As I stared at it,
my escort-guide told me that that item was a 'breaker' used on high
tension power lines, and a utility company had just blown one and
needed this replacement !!!! *Any guess as to its current rating? Hate
to be UNDER that when it went off!


I used to repair machines at westinghouse Beaver PA that made switch
gear of all sizes it was a fascinating place. They offered me a job
but I declined, just a few years later everyone with less than 20
years experience lost their jobs in layoffs. Later 2/3rds of the plant
was demolished, just the slab showing where the old deparments remains
today...

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Default What's the largest Main Breaker available?

In article , tangerine3
@toyotamail.com says...

Most homes have a 100A to 200A main breaker. Industrial buildings and
farms often have a 300A or 400A main. Factories with lots of electrical
machinery have multiple main panels, (often 3 phase), but what is the
largest main breaker that is sold?



For the the power company's high voltage electric lines, it is called a
"Recloser". Also when the voltage increases, the amperage decreases, so
these are not rated at very high amperages, but are rated for high
voltages...

http://en.wikipedia.org/wiki/Recloser


http://power.indiabizclub.com/catalo...ecloser~madras
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Default What's the largest Main Breaker available?

On Apr 4, 10:43*pm, wrote:
On Tue, 03 Apr 2012 23:48:53 -0400, wrote:
Geezzzzzz as if that aint enough power!!!! *I'd hate to have to pay that
electric bill. *And imagine the size of that transformer feeding it.
The biggest listed on that Westinghouse site was 4000 (for low voltage,
meaning 240/120 or three phase 208. *I know some buildings have 440 too,
I'm not sure just why, I suppose some motors run on 440, or they split
it into two 220/240 circuits like they do with 240 to 120.


480 generally comes in as wye 3 phase. They use the resulting 277v
line to neutral for lighting
They will have transformers to drop that to 208 3 phase, centertapped
for the 120.


But a centertap on 208 would only result in 104. *Or are the centertaps
not exactly centered, and only using the higher voltage half (120 + 88
volts)?

As much wiring as I've done, I have never understood how the 3 phase
systems get the desired voltages. *Just like how does one get 277v from
480v (half is 240). *Then too, why use 277v for lighting? *Unlike large
motors and electrical heating sources which are more efficient at higher
voltages, lighting is one thing that surely does not need higher
voltages and would require special bulbs, ballasts, and probably
switches too. *Seems sort of pointless....


To better understand 3 phase, use a phaser diagram. Draw a circle and
from the center outwards draw three lines to the circle's edge each
line is 120 degrees apart. Now you have a circle with what kindof
looks like a peace symbol.
Each line represents a phase of AC power. Now spin the wheel
[mentally] at 60 Hz and view from the circle's edge watching the TIP
of each line go by. As a function of time, each line will subtend a
sinusoidal waveform. Each waveform is what the 3 phase poer is
doing.

Now you can strt to play gaimes. What would be the voltage if the
three wires were connected between each line tip? What would be the
voltage if you measured from the tip to the center? etc etc. You will
notice that no matter which connection you make the waveforms will
always be 120 degrees apart.
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Default What's the largest Main Breaker available?

On Thu, 05 Apr 2012 00:43:31 -0500, wrote:

On Tue, 03 Apr 2012 23:48:53 -0400,
wrote:

Geezzzzzz as if that aint enough power!!!! I'd hate to have to pay that
electric bill. And imagine the size of that transformer feeding it.
The biggest listed on that Westinghouse site was 4000 (for low voltage,
meaning 240/120 or three phase 208. I know some buildings have 440 too,
I'm not sure just why, I suppose some motors run on 440, or they split
it into two 220/240 circuits like they do with 240 to 120.


480 generally comes in as wye 3 phase. They use the resulting 277v
line to neutral for lighting
They will have transformers to drop that to 208 3 phase, centertapped
for the 120.


But a centertap on 208 would only result in 104. Or are the centertaps
not exactly centered, and only using the higher voltage half (120 + 88
volts)?

The centertap is 120. It is the centertap of a 3 phase Y transformer.
208/sqr3=120.
The center tap of a single phase transformer is half the voltage.
240/2=120.
As much wiring as I've done, I have never understood how the 3 phase
systems get the desired voltages. Just like how does one get 277v from
480v (half is 240). Then too, why use 277v for lighting? Unlike large
motors and electrical heating sources which are more efficient at higher
voltages, lighting is one thing that surely does not need higher
voltages and would require special bulbs, ballasts, and probably
switches too. Seems sort of pointless....

480/sqr3=277 It is not a center tap of a single phase like 240/120

Higher voltage means less amps for the same amount of power. With
less amps you can use smaller wire and smaller raceways. Since they
use it in most large buildings you can bet it is not pointless.
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Default What's the largest Main Breaker available?

On 4/5/2012 12:43 AM, wrote:
....

As much wiring as I've done, I have never understood how the 3 phase
systems get the desired voltages. Just like how does one get 277v from
480v (half is 240). Then too, why use 277v for lighting? Unlike large
motors and electrical heating sources which are more efficient at higher
voltages, lighting is one thing that surely does not need higher
voltages and would require special bulbs, ballasts, and probably
switches too. Seems sort of pointless....


As the other posters note, you need to consider the phaser diagram. The
Wikipedia article isn't _too_ bad; reading it won't hurt.

But, as to the question posed above, look at it the other way 'round...

Suppose we want to take two phase wires (of a three-phase distribution)
and a neutral to make a three-wire household service supplying 120 V
between each hot wire and ground. The neutral will become the grounded
conductor, the two phases the hot and neutral conductors. If we grant
this, the wye voltage is 120, so the delta voltage will be ˆš3 x 120 =
208 V. This is the three-phase line voltage necessary in this case
which is why that is a common distribution value for three phase
systems--it was worked out so that the end result will be that desired.
Note that the two 120 V sources are not opposite in phase, and will
not give 240 V between them.

On the other hand, suppose we do want a 240 V service. Then this must be
the line voltage, and the voltages to neutral will be 139 V, not 120 V.
A 120 V three-phase service will give only 69 V from line to neutral.

http://en.wikipedia.org/wiki/Three-phase_electric_power

Also as noted, the reason for the higher voltages in commercial building
is that the lower amperage requirements for smaller conductors
translates into a less expensive installation overall. The cost-savings
escalate the larger the facility.

--


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Default What's the largest Main Breaker available?

On Apr 4, 5:55*am, Ed Pawlowski wrote:
On Tue, 03 Apr 2012 22:07:50 -0500, wrote:

We have a 1200A in or plant, but I *know they do make a 4000A. *I
don't know the biggest for sure though.


Geezzzzzz as if that aint enough power!!!! *I'd hate to have to pay that
electric bill. *And imagine the size of that transformer feeding it.
The biggest listed on that Westinghouse site was 4000 (for low voltage,
meaning 240/120 or three phase 208. *I know some buildings have 440 too,
I'm not sure just why, I suppose some motors run on 440, or they split
it into two 220/240 circuits like they do with 240 to 120.


All of our machines run on 440V 3ph. *Keeps the wire size down.

I live it when a visitor says "wow, this is a big place, you must make
tons of money". *They go into shock when I tell them the electric bill
last month was $30,000, the gas bill was $20,000 but goes up when we
turn the heat on.


Similar story...

We rent a local armory for a kid's related sporting event a couple of
times a year, always during the winter months. Everyone assumes that
the local businessman that bought the armory was rolling in dough.
"What a great deal he got! He bought this old building for $1,000 and
now rents it out for concerts and events. He must be making boat loads
of money."

They change their tune when we tell them that the owner spent 1
million dollars on the roof as soon as he bought it to stop the leaks
that prevented any other repairs from being done. Then he upgraded the
electric to handle the requirements of the events he planned to hold,
installed a fire protection/sprinkler system before the city would let
them open, etc. Even with the favorable code treatment the city gave
him so that he could start to recoup his money, it's been years and
he's still in the hole.

Because we're a non-profit, he rents the armory to us for a few
thousand for the weekend, even though it costs him $1,200 a day to
heat the place.

BTW...the owner is blind and has never seen the building he owns and
operates. Rumor has it that he was told that if had been able to see
the building, he never would have bought it. He supposedly wanted to
be bring the building back to its former glory days after years of
neglect.

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Default What's the largest Main Breaker available?

On Apr 5, 6:43*am, wrote:
On Tue, 03 Apr 2012 23:48:53 -0400, wrote:
Geezzzzzz as if that aint enough power!!!! *I'd hate to have to pay that
electric bill. *And imagine the size of that transformer feeding it.
The biggest listed on that Westinghouse site was 4000 (for low voltage,
meaning 240/120 or three phase 208. *I know some buildings have 440 too,
I'm not sure just why, I suppose some motors run on 440, or they split
it into two 220/240 circuits like they do with 240 to 120.


480 generally comes in as wye 3 phase. They use the resulting 277v
line to neutral for lighting
They will have transformers to drop that to 208 3 phase, centertapped
for the 120.


But a centertap on 208 would only result in 104. *Or are the centertaps
not exactly centered, and only using the higher voltage half (120 + 88
volts)?

As much wiring as I've done, I have never understood how the 3 phase
systems get the desired voltages. *Just like how does one get 277v from
480v (half is 240). *Then too, why use 277v for lighting? *Unlike large
motors and electrical heating sources which are more efficient at higher
voltages, lighting is one thing that surely does not need higher
voltages and would require special bulbs, ballasts, and probably
switches too. *Seems sort of pointless....


You have to understand that the 277volts is a sort of average.
If you took an instant in time, because it is AC the three phases are
not at the same voltage. They can be at anything from plus 360v to
minus 360v.

So you can't just add them together.
The reason is the voltage has direction as well as size and they are
120 degrees apart.

One way to grasp it is to consider.
If you went four miles North from your house and then went three miles
West, how far would you be from your house?
Answer is not seven miles but five miles.

These are vectors because they have direction as well as distance and
both have to be considered if you want to add them up, (Or do
anything else)

The voltages in a three phase sytsem are excatly the same. They are
vectors.
You have to take into account the angle between themas well as their
size.
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Default What's the largest Main Breaker available?

On Thu, 5 Apr 2012 09:33:24 -0700 (PDT), DerbyDad03
wrote:





Because we're a non-profit, he rents the armory to us for a few
thousand for the weekend, even though it costs him $1,200 a day to
heat the place.

BTW...the owner is blind and has never seen the building he owns and
operates. Rumor has it that he was told that if had been able to see
the building, he never would have bought it.


Very generous of the owner.


When we first bought this building, one section was used as warehouse
from the old plant. Two people would bring material over first thing
in the AM. turn all the lights on and leave them on all day; 9 to 10
hours and went back to the other building. A couple of bulbs burned
out so the shipper asked me to get a couple of new bulbs.

She handed me a bulb and it was 1,000 watts. Electric at the time was
15¢ a kW. Not only was the bulb $110 to replace, it costs $36+ a day
to light an empty building with 30 fixtures. Once explained, they
turned on only a couple of needed lights and the overhead was less.

We since replaced those 1000 watt fixtures with 200 watt fluorescent.
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