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American Voltage

American Voltage

American Voltage

(OP)
Hi
I am trying to find the common voltage level(LV)of medium to large industrial plants in North America.  All I can ascertain at present is a domestic level of 120V 60Hz P-N.
Which based on the standard UK distribution sytem would give 210V P-P ?
But do industrial (petro-chem) use this as there main LV distribution voltage level?

SANDITECH

RE: American Voltage

Common US (Nominal) Voltages (<1000V)

Three-phase:

208V/120V  (wye - so 208V P-P, 120V P-N)
480V/277V  (wye)
240V/120V  (delta with one phase center-tapped - not recommended or widely used)

Single-Phase:

240V/120V (single-phase 3-wire - primarily residential and light commercial)

Some 240V equipment is dual-rated for 240V and 208V, but don't count on it.

HTH  

RE: American Voltage

Slightly expanded version of dpc's response.

Industrial: US - 480/277 Y is dominant, especially new installations. Some 480 delta is still out there, plus a little bit of 600V in the South East textile industries. Canada (also part of N. America last I checked) - the dominant supply is 600V (delta?), with some 480 systems in select industrials. In some areas the 240V options mentioned by dpc may be the only thing available, but for the most part utilities like to give out 480 for industrials because it means smaller transformers (translate; cheaper).

Medium Voltage: 2300V and 4160V for motors etc., 12.47kV for sub-distribution and 13.8kV for exceptionally large motors.

Commercial (& some light industrial areas): US - 208/120 Y is split in dominance with 240V with center tap because is makes lighting circuits easier to implement. Canada uses 600V in commercial systems as well, but I have been corrected in the past on this so I think they also have 208/120 Y as well (I'm sure some Canadians will pipe up on this).

Residential: Almost exlusively 240/120V 1 phase in both countries. If you get on your knees and beg, they MAY grant you a magnanemous gift of 3 phase power (I know, because I got it after begging for 8 years).

"Venditori de oleum-vipera non vigere excordis populi"

RE: American Voltage

Our petchem facility has a sitewide distribution voltage of 13.8kV.  Utilization voltage for large motors is also 13.8kV.  Large motor busses are either 4.16kV or 2.4kV.  Low voltage is 480V.  

Other common industrial voltages are 13.2kV and 6.6kV.

RE: American Voltage

We also have 347Y600 volts 4-wire 3-phase in parts of Canada and upstate New York.

Highway lighting power is either 480 volts 2-wire end grounded or 240/480 volts 3-wire single phase.

Some parts of Cleveland Public Power have 480 volt ungrounded single phase streetlighting power. Cleveland Public Power did not start grounding their stuff until 1991. You do not want to step on a CPP handhole cover or lean against a streetlighting pole in Cleveland, Ohio because CPP's stuff is only Code 2 out of 3 times. In the late 1980s they were still using GREEN hot leads!

RE: American Voltage

Standard US voltages (ANSI C84.1-1989) are:
(bold-preferred)

2-Wire:
  120
3-Wire LV:
  120/240
  240
  480
  600
3-Wire MV:
  2 400
  4 160
  4 800
  6 900
  13 800
  23 000
  34 500
  46 000
  69 000
3-Wire HV:
  115 000
  138 000
  161 000
  230 000
3-Wire EHV:
  345 000
  500 000
  765 000
  1 100 000
4-Wire LV:
  208Y/120
  240/120 (from delta with one winding center tapped)
  480Y/277
4-Wire MV:
  4 160Y/2 400
  8 320Y/4 800
  12 000Y/6 930
  12 470Y/7 200
  13 200Y/7 620
  13 800Y/7 970
  20 780Y/12 000
  22 860Y/13 200
  24 940Y/14 400
  34 500Y/19 920
  

RE: American Voltage

(OP)
Thanks to all, having now seen the mass of voltage variants, I'm glad I live in the UK/Europe.

SANDITECH

RE: American Voltage

Sanditech,
People think of the US as one homogenous "country" just because we all speak the same language (sort of). We are actually a collection of semi-sovereign states, each with it's own history and developement rate. Many are the same, but many are not. And even within states, control over things like electrical distribution was hotly contested among some cities and economic areas in the early days of electricity as each developed their own way of doing things. Add to that the need to transmit over much larger distances than what you worry about in Europe, and you end up with a list like jghrist's.

You mean to tell me that every country in Europe has exactly the same voltage standards? Wow. Given your history of not getting along with each other, I find that hard to beleive!

"Venditori de oleum-vipera non vigere excordis populi"

RE: American Voltage

And that's just the standard voltages.  Most of the transmission lines in my neck of the woods are 100 000 volts - not on the list.

RE: American Voltage

jraef,

It is actually Europe's history of not getting along with each other that gave rise to a much more standardized set of voltages.  WWII wiped out so much infrastructure that they, particularly on the continent, had to basically start over again in the late 40's.  I'm sure that if we in the US had to start over we might well have many fewer voltages in use than we do now.

RE: American Voltage

jraef wrote:
You mean to tell me that every country in Europe has exactly the same voltage standards? Wow. Given your history of not getting along with each other, I find that hard to beleive!


Untill some 10 years ago England had a slightly different voltage standard, 3 phase 240/415 V, the rest of Europe was 220/380V, it was changed to a common standard 230/400 V.
The difference from the old standards are so small that old equipment can still be used.

In Norway you can find 3 phase 230 V delta.
Most house installations are 3 phase.

England do use a standard plugs for domestic installations that is very different to the ones used in the rest of Europe, and there are some differencies in the grounding terminals, but ungrounded plugs can be used without a converter.

MV installations in factories are normally 3 phase 6 or 10kV

RE: American Voltage

davidbeach,
That is an interesting perspective, it never occurred to me. Maybe that is what we are doing in Iraq and Afganistan, standardizing their infrastructure! I'm surprised the spin doctors haven't caught on to that one... yet.

"Venditori de oleum-vipera non vigere excordis populi"

RE: American Voltage

Yep!! just as I thought; its black copters and 60Hz... We rule.
Say! just how do clocks run on 50Hz anyway?

Best Regards
Pennpoint

RE: American Voltage

From the list provided by jghrist:

1 100 000 Volts
Is this the highest voltage in use today in the world? (On transmission lines)

Just curious

Regards
Ralph

RE: American Voltage

There are still a few 575V systems out there, but they are rare.

Bigbillnky,C.E.F.....(Chief Electrical Flunky)

RE: American Voltage

Say! just how do clocks run on 50Hz anyway?

Best Regards
Pennpoint


If you bring your mains controlled clock you will get a short workday, but clocks are built for 50 or 60 Hz.

Greetings Aksel, Denmark

RE: American Voltage

bigbillnky
I am currently working on a project with the motor voltage at 575; 3?.  Have no clue as to hold old the plant is, but it's the specification that was given to me.

RE: American Voltage

575 volts is the standard utilization voltage for a 600 volt system.

RE: American Voltage

In Australia thank goodness 240/415 50Hz is universal for residential/light industrial, and the plugs are all the same everywhere too !

However historically the railway industry in each of the seven states started off laying tracks everywhere within their own area, but with a different gauge. BIG problem at the borders hehehe.

RE: American Voltage

AFAIK, 765kV is the highest AC transmission voltage in use in the U.S. There are a few +-500kV DC lines.

RE: American Voltage

For domestic supplies worldwide:
http://kropla.com/electric2.htm

In terms of population, 50Hz wins (ok, China helps).

davidbeach - interesting theory, it is the two WWs after all that started the whole European Union thing.
Incidentally, everyone in Europe gets on fine now! except when we play football (that's soccer) and a few other occasions.

RE: American Voltage

We also have 240 volts corner grounded 3-wire 3-phase power and a smaller amount of 480 volts corner grounded.

We also have resistance grounded 3-wire 3-phase power in a few instances where reliability is important and a limited source of ground fault current is needed for tracing and disconnecting ground faults in a timely matter.The voltage levels in these cases are usually 480 volts, 600 volts, 1,040 volts, and 4,160 volts. The supply transformers would be 277Y480, 437Y600, 600Y1,040, and 2,400Y4,160 volts.

There are also a few places that do have oddball voltages or 25 Hertz power. Here is Cleveland the steel mills make their own 25 Hertz power for big motors using cycloconverters. When machine speed goes down and machine torque goes up the optimal frequency drops down to about 15 to 30 Hertz. In actuality, the cycloconverters for each motor are adjustanble in frequency both for starting purposes and to tweak the speed.

In 1 place where I worked some 40 Horsepower 10 pole 60 Hertz motors had been replaced with 4-pole 100 Horsepower or 125 Horsepower inverter duty motors. They then used variable frequency drives to feed 24 Hertz power into the motors. Thanks to VFDs you can generate any custom frequency you would want.

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