Newbie: tips on how to start?

[Rui Maciel]

Why is that?


Rui Maciel

 

[Cydrome Leader]

It makes you see stars, and makes your muscles contract violently.
And there might be a small burn mark.
Having good quality plastic soles under your shoes makes single contact
oke. Dont use leather soles.
My limit fo far is 2X500 volt from a falling radio I tried to catch.....
We both survived.
Automatic reflexes are so dangerous when you work with electricity.

Interesting.

Here in US with 120, the danger is almost always from what you end up
hitting or falling off (like a ladder) /into than from the shock itself.

I've never been burned from 120 or seen stars or anything like that. I've
touched high voltage DC equipment where it doesn't even matter if only
one hand is in the pocket or or anything like that. At 8kV you're getting
a one handed shock unless you have special boots on.

The last actual line voltage electrocution story from around here was from
somebody running an electric drill outdoors on a hot day. They sweated
into the drill, couldn't let go and died.

How often do people drop dead from actual electrocutions in places that
use 240, just doing plain tasks like you might at home or outside?

 

[Baron]

Cydrome Leader Inscribed thus:

Interesting.

Here in US with 120, the danger is almost always from what you end up
hitting or falling off (like a ladder) /into than from the shock
itself.

I've never been burned from 120 or seen stars or anything like that.
I've touched high voltage DC equipment where it doesn't even matter if
only one hand is in the pocket or or anything like that. At 8kV you're
getting a one handed shock unless you have special boots on.

The last actual line voltage electrocution story from around here was
from somebody running an electric drill outdoors on a hot day. They
sweated into the drill, couldn't let go and died.

Possible, but I suspect an urban legend.

How often do people drop dead from actual electrocutions in places
that use 240, just doing plain tasks like you might at home or
outside?

People do die from electrocution on 240 volt AC mains. More often than
not the reflex action causes you to pull away. I agree with your
comment that "the danger is almost always from what you end up hitting
or falling off (like a ladder) /into than from the shock itself."
DC is far more likely to kill you, simply because the muscle contracts
and makes it impossible to let go.

 

[Jamie]

Cydrome Leader Inscribed thus:




Possible, but I suspect an urban legend.




People do die from electrocution on 240 volt AC mains. More often than

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I would hope that to be the fact!

not the reflex action causes you to pull away. I agree with your
comment that "the danger is almost always from what you end up hitting
or falling off (like a ladder) /into than from the shock itself."
DC is far more likely to kill you, simply because the muscle contracts
and makes it impossible to let go.

--
"I'd rather have a bottle in front of me than a frontal lobotomy"

"Daily Thought:

SOME PEOPLE ARE LIKE SLINKIES. NOT REALLY GOOD FOR ANYTHING BUT
THEY BRING A SMILE TO YOUR FACE WHEN PUSHED DOWN THE STAIRS.
http://webpages.charter.net/jamie_5"

 

[Cydrome Leader]

Cydrome Leader Inscribed thus:


Possible, but I suspect an urban legend.

If the chicago suntimes or tribune had a functional search feature, you
could locate the story, but that's a different story.

People do die from electrocution on 240 volt AC mains. More often than
not the reflex action causes you to pull away. I agree with your
comment that "the danger is almost always from what you end up hitting
or falling off (like a ladder) /into than from the shock itself."
DC is far more likely to kill you, simply because the muscle contracts
and makes it impossible to let go.

Is it 240 from either side of the line to ground, or how does that work? I
asked all about this when I was in Ireland, but forgot the answer.

 

[Sjouke Burry]

If the chicago suntimes or tribune had a functional search feature, you
could locate the story, but that's a different story.


Is it 240 from either side of the line to ground, or how does that work? I
asked all about this when I was in Ireland, but forgot the answer.

No,1 phase and 1 return.
The return is actually the centre tap of the 3 phase system(3 X 240 V),
and equivalent to ground.

 

[Cydrome Leader]

No,1 phase and 1 return.
The return is actually the centre tap of the 3 phase system(3 X 240 V),
and equivalent to ground.

So it's usually some sort of Wye connection where one side of the power
would in theory br safe to just touch if you were standing in a puddle?

What's confusing in the USA is the mix of 120/240 and then the 120/208
circuits from 3 phase power in larger settings.

So while most homes may have 240volts available, an office building may
only have 208 between any two legs of the three phase power they have.

For a computer, it doesn't really matter, but for things like induction
motors, it's more of an issue.

 

[Jasen Betts]

People do die from electrocution on 240 volt AC mains. More often than
not the reflex action causes you to pull away. I agree with your
comment that "the danger is almost always from what you end up hitting
or falling off (like a ladder) /into than from the shock itself."
DC is far more likely to kill you, simply because the muscle contracts
and makes it impossible to let go.

AC can do that too, My dad had trouble putting a skilsaw down after
cutting the lead. luckily he was able to out-distance the extension
lead. Next time he used it with an isolating transformer.


--- news://freenews.netfront.net/ - complaints: [email protected] ---

 

[baron]

Cydrome Leader Inscribed thus:

So it's usually some sort of Wye connection where one side of the
power would in theory br safe to just touch if you were standing in a
puddle?

Normally the centre tap is bonded to earth at the distribution
transformer, such that the Neutral and earth are at the same potential.
The Blue, Yellow, Red phases supply the 240 volt feed. Often you will
find that one side of the street is one phase and the other side of the
street is another. They do try to balance the phases by connecting
equal numbers of homes to each phase. In the UK its rare to have a
domestic property supplied with all three phases.

 

[baron]

Jasen Betts Inscribed thus:

AC can do that too, My dad had trouble putting a skilsaw down after
cutting the lead. luckily he was able to out-distance the extension
lead. Next time he used it with an isolating transformer.


--- news://freenews.netfront.net/ - complaints: [email protected] ---

Nasty ! I'm glad he's OK. I use a GFI on power tool cables.

 

[Cydrome Leader]

Interesting.

Here in US with 120, the danger is almost always from what you end up
hitting or falling off (like a ladder) /into than from the shock itself.

I've never been burned from 120 or seen stars or anything like that. I've
touched high voltage DC equipment where it doesn't even matter if only
one hand is in the pocket or or anything like that. At 8kV you're getting
a one handed shock unless you have special boots on.

The last actual line voltage electrocution story from around here was from
somebody running an electric drill outdoors on a hot day. They sweated
into the drill, couldn't let go and died.

How often do people drop dead from actual electrocutions in places that
use 240, just doing plain tasks like you might at home or outside?

I found the drill story in here, on page 14.

http://www.rmmi.org/Safety/documents/FocusFourModule1final.pdf

 

[Baron]

Cydrome Leader Inscribed thus:

I found the drill story in here, on page 14.

http://www.rmmi.org/Safety/documents/FocusFourModule1final.pdf

Thanks for that very useful & informative info.

 

[Jasen Betts]

Jasen Betts Inscribed thus:


Nasty ! I'm glad he's OK. I use a GFI on power tool cables.

Didn't have them back in 1975, plastic power tools tools were a
rarity too.




--- news://freenews.netfront.net/ - complaints: [email protected] ---

 

[Michael Black]

Become a part of a forum and mingle with other hobbyists..

He's already done that, he posted here.

Michael

 

[Jamie]

I built my first electrical circuit at the age of 11 or 12 (1946-47)
while living in house that had no electrcity, only gas, for heating
lighting and cooking. It was nothing more than a couple of switches, a
battery and a lamp mounted on a piece of plywood. Couple of years
later built my first radio and it worked; sort of! Went on from there
experimenting learning how to solder correctly, was given a couple of
books. Acquired old bits of radios and things electrical, jars of
screws nuts, bolts tape, tubing, brackets etc. etc. Broke quite few
things and/or didn't fix em, while learning but it was cheap learning
at that.
Later learned electrical theory which explained why and how things
worked.
That led to a 40 year career in telecommunications and other
opportunities ................... now approaching 80 I still dabble
and first inclination is to fix something that is broken than replace
it. And truthfully most of the stuff around here is kinda old but it
works fine.
Whether you make or fix something yourself, contract it or out or buy
anything outright one finds oneself much more knowledgeable and
willing to get advice. The effect on the bank account is also healthy
and one ends up debt free and able to sleep at night!
Must go and put the battery back in one of the three smoke detectors;
had to take it out recently when very humid weather kept setting it
off. the other two on the main floor not as sensitive!
Fiddle and have fun and wonder and learn as you go along; it can be
anything from making a watch battery fit with a piece of tin foil to
wiring up a speaker for the patio. Just work safe.
Oops just remembered that I was vacuuming the spare bedroom yesterday
and one of the outlets is cracked, must replace that right
away .......... safety item.

8 Years old, I was given a gift at xmas where it had knife switches,
duals,singles etc, lights, buzzers and battery holders. I made my first
3 and 4 way switches to operating bells and lights.. then I got the
idea to apply that to the house. That's where I was stopped! At age 10,
I helped my father wire the barn. That's when I learned how the
electricians did those fancy light circuits. I told my father I thought
the electrical parts were a little too basic and should be improved. He
told me to learn electronics and get out of his hair because it was
beyond him!


I was dangerous then!

 

[[email protected]]

Didn't have them back in 1975, plastic power tools tools were a
rarity too.

If by "plastic" you mean double-insulated, no, by 75 they were *very* common.
They started coming out in the mid '60s, IIRC, and were ubiquitous by '75.

 

[[email protected]]

It would be simpler to make sure you can't cut the cord with the saw.

Batteries? ;-)

 

[Rui Maciel]

This isn't a forum, it's a newsgroup.

In your opinion what's the difference?


Rui Maciel

 

[[email protected]]

USENET has newsgroups, the web has forums.

Bzzzt! A "forum" is a place for public discussion.

This is a USENET newsgroup. It's echoed on a few web pages, but it's
still USENET.

....and is a public forum.

http://www.merriam-webster.com/dictionary/forum

Main Entry: fo·rum
Pronunciation: \?fo?r-?m\
Function: noun
Inflected Form(s): plural forums also fo·ra \-?\
Etymology: Latin; akin to Latin foris outside, fores door — more at door
Date: 15th century

1 b : a public meeting place for open discussion c : a medium (as
a newspaper or online service) of open discussion or expression of ideas

 

[Rui Maciel]

USENET has newsgroups, the web has forums.

This is a USENET newsgroup. It's echoed on a few web pages, but it's
still USENET.

You seem to be a bit confused. As it was already pointed out, a forum is nothing more than a public
meeting place for open discussion. Sites which are ran on software packages such as phpBB are still
forums, just like any usenet newsgroup you happen to come across. Just to drive the point home,
google offers a web interface to usenet newsgroups through it's google groups service. Do you
believe that accessing sci.electronics.basics through google groups would make it a forum but
accessing it through a usenet client would take that definition away from it?


Rui Maciel