American electrical engineering

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.

Si:
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?

Generally speaking, the limit is 24 volts for speaking

I have no idea, it's not something that you'll see in a house, Industrial/Commercial only

cr0sh:

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.

Obviously means that the guy was just like "Well fuck, I got this blue wire lying around, I'll just use it" :stuck_out_tongue:

Yep, it's stupid, you don't even have to overload it to cause a housefire, when the wire heats up, it expands, then contracts when it cools, eventually pushing the terminals out, slipping itself out... causing arcing and fires

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.

The proper name for a "breaker box" is a service panel.

KE7GKP:
This is probably more definitive and authoritative than the mass of opinions presented here so far:
http://www.allaboutcircuits.com/vol_5/chpt_2/2.html
It also highlights some of the differences between IEC, UK, US, and Canadian power conventions.

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

I have no respect for anyone dissing their own country (or anyone else's, for that matter.)

Threadjack ahead, and I apologize...

Kenneth Lay and Glenn Beck - need I say more (I seriously could go on for pages)?

Our country is hosed beyond belief; most of the population either doesn't care, or is helping it along down the path to ruin. There is little you or I can do to stop it; I'll continue to vote, for what little good (or bad) it does, I'll demonstrate where I can, and I will donate to those causes I think can help. Ultimately, though, it seems too little, too late - especially given the Overton window is so far out of whack that so-called democrats look and act almost like moderate republicans of the 1980s. That's supposed to be progress?

I'm supposed to cheer when so many states want to take away women's rights to their bodies; where our own government whined about such a small percentage of the budget over it, almost bringing the government to a dead halt - for some nearly infinitesimal portion of the budget?

I'm supposed to be quiet when the majority of Americans don't even understand evolution, and a great percentage want to teach our children creationism and intelligent design instead? I'm supposed to be silent when a large portion of the voting public make statements against being intelligent, so-called "anti-intellectualism" - that somehow being intelligent is "elitism"? WTFBBQ?

The honest fact is, a great portion of the voting public America seems to think Jesus is coming back any second (oh, maybe May 21st?), the end-times are a-comin', and even if they aren't, they're thinking they should maybe help it along. Rational discourse? Logic? The scientific method?

We just had a 2-bit preacher burn a freakin' book knowing full well what it could cause, and halfway around the world a bunch of other backwards-thinking people riled up by their leader did the expected thing and killed some people? Over what? A fairy tale.

This is the world and nation we've given our children. A world in which oil isn't getting any cheaper, but rather than cut the spending on the war machine here in the US, the spending is instead cut on alternative energy research. Rather than shore up our infrastructure, we cut the spending to the US Army Corp of Engineers - because who needs levies, huh?

This isn't a republican vs democrat thing, either. It's an "us" thing. We voted them in (we had little real choice), there ain't much we can do about it except sit back and watch the show.

/threadjack over :~

Good thread-jack.

I'll bet you feel better for getting that off your chest! I think you describe a world problem. Its not just America.

When I was growing up reading science fiction, I was looking forward to a world of science and logic. What a disappointment.

You are not alone in your views.

the end-times are a-comin',

Yes, I'm sure they are - I heard something like 37% of the electorate thought that Sarah Palin was a good candidate for the White House.
She's just GWB with lipstick.

Haha this thread's got pretty funny :smiley:

When I was growing up reading science fiction, I was looking forward to a world of science and logic. What a disappointment.

It's around in some places - I'm looking forward to making it happen.

As nobody has asked yet - what's the book? (or what's it primarily about if you don't want to say what it is).

Apart from unrealistic stuff like flying cars or cars that go in all directions (how difficult it would be to replace all the cars in the world with ones that function differently although most people do seem to be driving cars less than 10 years old now - probably due to the scrappage scheme) a lot of stuff in sci-fi movies is possible and we are approaching the time where a lot of it is possible. In the next 10-20 years or so there is going to be more a lot of change (and sci-fi movies will start to have old tech) and I can't wait!

As nobody has asked yet - what's the book? (or what's it primarily about if you don't want to say what it is).

Thanks Mowcius, I'm always willing to lever in a plug or two ....

The book's the third of my contributions to McGraw Hill's 'Evil Genius' series, following '15 Dangerously Mad Projects for the Evil Genius' (out end of May - http://www.dangerouslymad.com).

The working title for this one is 'Practical Arduino + Android Projects for the Evil Genius'. It includes a section on Home Automation, hence the need for information on US wiring. This will be accompanied by copious warnings, and legal disclaimers :wink:

If the Amarino folk catch this - I plan to use your excellent project in some places - and due credit will be given. But I am also using a sound interface as the Android / Arduino link - the lowest common denominator for cheap Android tablets without BT.

It should be in the shops in time for X-mas.

Wow, what a mix of stuff on this thread! Good for you Si, your book should address some of the problem cr0sh described, at least a bit, however slightly.

Technology really divides population in "half" and it's more difficult to cross that divide to the "knowing technology" side. Arduino and your books should help the climb.

People that I know of were more genuinely interested in science back in the 60's and 70's and they loved Sci-fi stuff too. Today kids get bombed by too many tech toys and movies and it's harder to get their interests on understanding electronics. Back then building a radio would be cool enough when the retronym AM broadcast was not even invented/popularized.

Although we don't yet have hover cars and can't do space travels, I have just purchased an i-pad-2 to upgrade myself from i-nothing to i-onething. If you have a tablet today, you don't have to pretend you were looking at a hand held device like in star trek. That's just maybe 3 decades of progress?! I paid twice as much as my ipad 11 years ago to buy a Celeron 366 laptop, which is heavy and has no ethernet.

Thanks Liudr.

I tell you what is heartening, and thats that my son (the younger one who hasn't discovered girls and guitars yet) sits with me while we do some experimenting with a new module or some project for a book. I can leave him to wire up some breadboard while I fetch us a drink. Its great. He does a bit of electronics at school in design and technology, but I suspect he's scaring the crap out of his teacher.

Then there is the whole modding and hacking thing, which while not always built on the soundest of engineering principals, is still better than no interest in understanding how things work. The kids love this, the first thing they do with an iPod is jailbreak it.

Did Gene Rodenberry fall through a gap in the space time continuum? We have communicators and tablet thingies. When can we expect to have warp drive? BTW - am I alone in identifying more with Spock than Kirk?

am I alone in identifying more with Spock than Kirk?

Well obviously, yes.
We true engineers identify with Scottie.

Now I'm picturing the next noob-E thread wanting to know why they need a resistor with an LED when it "works fine without one".

Cause she caaahnt tehk mooch mohrrr of thaaat, Captin'!</Scottie accent>

Valalvax:
Generally speaking, the limit is 24 volts for speaking

I have no clue what "for speaking" was supposed to be... obviously I got distracted lol

There was a great spoof ad on atomfilms.com about flying cars - put out by the bus company!
Wish I could find it, was really funny!

Well obviously, yes. We true engineers identify with Scottie.

That is not logical.

Si:
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.

Not any more it isn't. You'll still find it in houses but it was phased out a few years ago.

Edit: just to clarify I mean in the UK. We're now the same as the rest of europe in that house wiring is the same as consumer wiring.