American electrical engineering

I'm from England, and I am doing some research for a book, for which the audience will largely be American. So I want to make sure I'm not misleading people.

It seems to me that here in England, we have our own words for a lot of things that go on in home electrics that are not the same as in the US. Our cultures started on divergent paths long before people started wiring up their homes.

So, I have some questions.

  1. Are all domestic supplies in the US 110V at 60Hz? (its 230V at 50 Hz in the UK)
  2. Is it true that what in the UK we call 'mains sockets' are called 'AC outlets' in the US?
  3. In the US, what do you call the three connections from an appliance? In the UK, its Earth (green), Neutral (Blue), and Live (brown). Although not all appliances use the earth.
  4. This is different in the house wiring (behind the walls) where the colour (color) scheme is red for live, black for neutral an bare copper for earth. What is it in the US?
  5. Our houses used to have fuse-boxes (a board with proper fuses in a cupboard (closet) somewhere. Now we have 'Consuler Units' which have a load of plug-in earth leakage sensing switches (MCBs) in place of the fuses. is this the same in the US?

Anything else that anyone knows about thats different in the US?

Other parts of the world, please join in too with your names for things.

Now we have 'Consuler Units'

They may have those in embassies, but we have "consumer units".

Isn't an "AC outlet" where you buy air-conditioning?

In the UK, its Earth (green),

sp." green/yellow"

Now we have 'Consuler Units'

They may have those in embassies, but we have "consumer units".

Ah, very good! I may just have to learn to spell rather than always saying yes to the top option on the spell-checker.

Surely the spell checker would have said "consular"?

Hello Si,
I live in California. I'm not an electrician, however I have worked in construction my entire adult life and I've picked up a thing or two. The answers to some of your questions: As far as I know, homes in the U.S. have three wires from the public utility poles to each home. Homes are normally two phase AC. There are two HOT (or live) wires and one NEUTRAL. The wire you call EARTH we usually call GROUND (or earth) and is connected to either a long copper rod driven into the earth or sometimes a cold water pipe, both are at the home. The two HOT wires are 110 volts each to the NEUTRAL wire and are out of phase with each other so there is 220 volts from HOT 1 to HOT 2. The HOT wires are BLACK, the NEUTRAL is WHITE, and GROUND is GREEN or bare copper. The same colors apply to appliance wiring. Yes, here we call them AC outlets or AC recepticals (not sure if thats the correct spelling). AC outlets are normally 110 volts at 60Hz, although there are exceptions. For example, AC outlets for an electric dryer or an electric stove are normally 220 volts at 60 Hz. Older homes may still have fuse boxes with the old screw in type fuses. All new homes have breaker boxes with switch type circut breakers. Again, I'm not an electrician so if anyone who IS would like to add anything or correct me if I am mistaken about something, please do.

Hope this helps,
DigitalJohnson

While technically typical household wiring is two phase, it's really a single phase at the high voltage connection, and the transformer is wired to produce the two hots 180 degrees from each other. It's referred to as single phase, to differentiate from three phase, which has all three phases from the utility.

-j

Thanks DigitalJohnson and kg4wsv, thats really helpful.

UK neutral and US hot (live) are both black. That sounds like an accident waiting to happen for migrated DIY electricians :wink:

An issue with your subject line: the questions you ask primarily apply to what ELECTRICIANS know, not ELECTRICAL ENGINEERS. I would venture that only a small percentage of recently-graduated US electrical engineers could answer your questions.

My $0.02: domestic supplies are indeed 110V but heavy-duty appliances (washer, dryer, etc.) draw 208V. Recently, electric car chargers are drawing more attention, and they too are 208V.

--
The Quick Shield: breakout all 28 pins to quick-connect terminals

An issue with your subject line: the questions you ask primarily apply to what ELECTRICIANS know, not ELECTRICAL ENGINEERS.

And now I know 'electricians' are called 'electricians' too :wink:

We only hear about different names for things when they appear in films 'Realtor' vs 'Estate Agent', 'Attorney' vs 'Solicitor', that kind of thing.

Well it's interesting to read this thread to find out what people think they know too :smiley:

I'm just going to share the terms i've learned as an "average joe" growing up.

To me, "AC socket" is a very technical term. A more lax, casual term might be "electrical socket" or "wall socket" or, even though it's not really correct I've heard "wall plug". I personally would probably use "electrical socket".

The equivalent for "fuse box" now would be a "circuit breaker" or "breaker box". Of the 7 or 8 places i've lived they were all very similar and looked like this. http://www.dannychesnut.com/Electronics/Wiring/220/105_0582.jpg Usually they are located in the garage. If there is none you would probably find it in a closet somewhere in the house.

Hope that helps some.

Well it's interesting to read this thread to find out what people think they know too

Are we getting into Rumsfeldian 'known unknowns' territory here? :wink:

I personally would probably use "electrical socket".

Useful information. Thanks.

Si:

  1. Are all domestic supplies in the US 110V at 60Hz? (its 230V at 50 Hz in the UK)
  2. Is it true that what in the UK we call 'mains sockets' are called 'AC outlets' in the US?
  3. In the US, what do you call the three connections from an appliance? In the UK, its Earth (green), Neutral (Blue), and Live (brown). Although not all appliances use the earth.
  4. This is different in the house wiring (behind the walls) where the colour (color) scheme is red for live, black for neutral an bare copper for earth. What is it in the US?
  5. Our houses used to have fuse-boxes (a board with proper fuses in a cupboard (closet) somewhere. Now we have 'Consuler Units' which have a load of plug-in earth leakage sensing switches (MCBs) in place of the fuses. is this the same in the US?

Anything else that anyone knows about thats different in the US?

Other parts of the world, please join in too with your names for things.

  1. U.S. voltages are more typically 115-120 volts, 60 Hz.
  2. The term is usually just "outlets."
  3. Unless double insulated, appliances use the ground connection (green) in addition to neutral (white) and hot (black).
  4. As noted by others, bare copper is ground, white is neutral, black is hot, red is hot. Single phase power, 230 volts hot-to-hot. 115 volts each hot to neutral.
  5. Circuit breakers are now typical in most places. Some have ground fault breakers if they feed loads requiring such. More recent code requirements include "arc fault" protection from a loose wiring connection.

I agree with the observation this is a question for qualified electricians, not spectators on a microcontroller board.

Si:
I'm from England, and I am doing some research for a book, for which the audience will largely be American. So I want to make sure I'm not misleading people.

It seems to me that here in England, we have our own words for a lot of things that go on in home electrics that are not the same as in the US. Our cultures started on divergent paths long before people started wiring up their homes.

So, I have some questions.

  1. Are all domestic supplies in the US 110V at 60Hz? (its 230V at 50 Hz in the UK)
  2. Is it true that what in the UK we call 'mains sockets' are called 'AC outlets' in the US?
  3. In the US, what do you call the three connections from an appliance? In the UK, its Earth (green), Neutral (Blue), and Live (brown). Although not all appliances use the earth.
  4. This is different in the house wiring (behind the walls) where the colour (color) scheme is red for live, black for neutral an bare copper for earth. What is it in the US?
  5. Our houses used to have fuse-boxes (a board with proper fuses in a cupboard (closet) somewhere. Now we have 'Consuler Units' which have a load of plug-in earth leakage sensing switches (MCBs) in place of the fuses. is this the same in the US?

Anything else that anyone knows about thats different in the US?

Other parts of the world, please join in too with your names for things.

I'm sure your questions have been answered, but I'll give my own answers just cause

  1. Yes

  2. Both terms can be used, or a mixture, generally consumers will just say the outlet

  3. Earth/Ground (which is green), Neutral or Common (White), and Hot or Live (Red or Black, depending, Black is used for the highest voltage in a system generally (or maybe I got that backwards)) As a side note: That's only the colored wires inside the coat, the sockets themselves are silver, or copper or some similar color, generally not colored

  4. I'm not 100% on this, but I know that White is Neutral, pretty sure hot is Black and ground is either bare or green

  5. Not really sure what you're talking about, we have Circuit breakers, which are resettable fuses, when one blows you walk to the panel and flip the switch to restore power

biocow:
The equivalent for "fuse box" now would be a "circuit breaker" or "breaker box". Of the 7 or 8 places i've lived they were all very similar and looked like this. http://www.dannychesnut.com/Electronics/Wiring/220/105_0582.jpg Usually they are located in the garage. If there is none you would probably find it in a closet somewhere in the house.

Or outside on the wall, or in the basement (if your house has a basement). BTW - I've never seen an install that looked that "neat"; not saying they don't exist, but in some cases it is never that neat...

Sometimes the green ground wire will be green with a yellow stripe (I've seen that before). Just the other day, I was removing a couple of ceiling fans, and I noticed that their internal "hot" wires (leading to the motor and light) were red (though most of the time they are black). There's been a few cases where I have seen blue wires, but what they were used for I don't remember.

The standard is black=hot, white=neutral, green/bare copper=ground; this is the current standard for wiring colors from the breaker/fuse box to the outlets (and junction boxes, for mounted things like ceiling fans, light fixtures, etc). I would say that any other color you might see was either an addition by an installer who did it to differentiate something special (perhaps switching hots or grounds?), or he only had that on-hand and used it (and to hell with "code").

AC frequency here is 60 Hz, as has been mentioned - but voltage can vary quite a lot, depending on where you are at; in really crappy areas it can get as low as 90 VAC, in other areas you can see a swing up to 130 VAC. Double those for large appliances - which is something else: Here in the US we have two voltage levels in our houses, the larger level is reserved for specially plugs (or directly wired) for things like air-conditioners, hot water heaters, range/stove/oven, and similar. Also, these plugs for large household appliances are usually different than what you would find on say, a large 220 VAC welder (you either have to have a separate circuit installed with the special plug - which I think is an industrial plug - or build a custom inline "pigtail" - which I don't think it technically legal, but people do it).

If your house has breakers, about the only place you'll see a fuse(s) is on the outside of an air conditioning unit (behind a panel); they're inline with the circuit breaker for the unit (likely as an extra precaution; if I need to work on my AC I always pull them after turning the breaker off).

Some sockets (typically found in offices and hospitals) may be orange, designating them as operating off of a UPS (uninterruptible power supply) - not typically found in a home (but you never know - maybe if the house has a custom generator installation or other backup system?).

Finally - circuit wire comes in two flavors: Alluminum and copper. Connections are usually done to brass, alluminum or steel terminals (at the socket, or breaker, etc). Connections between alluminum and brass typically have a higher resistance than those connected from copper to brass. There have been instances of fires being started because of this (due to socket overload - as in when someone plugs in more than the circuit can handle - the junction can overheat and cause a fire before the breaker/fuse trips). However, alluminum is much cheaper than copper, so you see it used everywhere (if you have a house built or are house shopping - make sure your wiring and plumbing is all copper if you can).

Blue is DC power, in a system that contains DC and AC

It's against the NEC to use Aluminum in new houses, and if you remodel you have to redo the wiring to the new Code (granted, this has been the case for... a while)

Thanks for all the help everyone.

But...

Blue is DC power, in a system that contains DC and AC

Just when I was getting my head around all this, you have to go and throw that in :wink:

So, DC, high voltage?

Is this by any chance a hangover from Edison, to avoid the accidental electrocution of elephants?

A little bit of US electrical history.

I've lived in a few houses built around/before WWII that had fuse boxes.

My previous house, built in the early 1950s, had a breaker box, but it's possible that a previous owner had upgraded it (I didn't buy it until 1989).

The house my parents bought new in 1967 had a breaker box, but no GFCIs (Ground Fault Circuit Interrupters, the American term for shock protection circuits).

My current home, built in 1978 or 1979, has a breaker box, and a GFCI outlet in one bathroom that might be original, but might not: the kitchen an other bathroom have standard outlets, so it's possible that the one in the master bathroom was installed by a previous owner.

There's probably a history of the U.S. electrical codes available online that would tell you when the various requirement changes were made.

Valalvax:
Blue is DC power, in a system that contains DC and AC

It's against the NEC to use Aluminum in new houses, and if you remodel you have to redo the wiring to the new Code (granted, this has been the case for... a while)

I'm pretty sure in the case I saw it, said blue wire was -not- carrying DC.

Also - alluminum wire is still sold, and I am sure there are people out there using it for remodels (if not "new" houses) and paying off their inspector.

Remember - this is America - land of graft and willful ignorance.

Ultimately something to keep in mind, though; my house was built in 1973 - the wiring in it is copper (many years prior to purchasing it - there was a house fire due to the wiring; in fact, in many cases if there is a house fire in our neighborhood, it is due to this old wiring and overloading of the sockets); I think when they replaced the wiring, they went with copper, even though I am not sure if at the time it was necessary by code.

One of the things I looked for when I bought the house - that, and copper plumbing, block construction, and no HOA. If I could've found all of that in a new housing sub-division here in Arizona, I would've gone for it. But that is basically an impossibility. This was our first house, so going for custom construction was out (we couldn't afford it even if it was an option). Thus, we were left with looking at houses constructed pre-1980 or thereabouts.