Is it safe to operate an all alloy housing circular saw. My
15-year old industrial saw is reliable but the only thing aging
is the cord. The cord's insulation is cracking and deteriorating.
Last I'd check the ground wire is open but hidden from view.
What would be the hazards if I continue to use it?

Thanks

On Sun, 15 May 2005 05:32:39 -0700, Tim Zimmer wrote:

Is it safe to operate an all alloy housing circular saw. My
15-year old industrial saw is reliable but the only thing aging
is the cord. The cord's insulation is cracking and deteriorating.
Last I'd check the ground wire is open but hidden from view.
What would be the hazards if I continue to use it?

Thanks

The ground protects YOU. Replace the cord and connect the ground. The
bottom line is: How many more years do you wish to do woodworking?

"Tim Zimmer" wrote in message
news:1116159867.dda65d992f7a2135aa9763b69aaf9081@b ubbanews...
Is it safe to operate an all alloy housing circular saw. My
15-year old industrial saw is reliable but the only thing aging
is the cord. The cord's insulation is cracking and deteriorating.
Last I'd check the ground wire is open but hidden from view.
What would be the hazards if I continue to use it?

Thanks

Only death.

Open the case and replace the entire cord. Then you can use it for another
15 years.

On Sun, 15 May 2005 05:32:39 -0700, "Tim Zimmer"
wrote:

What would be the hazards if I continue to use it?

We'll all laugh at your funeral when they bury you in a cardboard box
for being a skinflint.

It's a fecking power cable. Coupel of bucks most, even for good quality
cable, and a few minutes job to fix. I have sympathy for people who get
hurt from damaged cables by accident (this is why workshop tools should
be tested and inspected, not just ignored) but to _know_ that it's a bad
cable and to carry on using it is just pikey.

It is quite an easy matter to replace the power cord and ground but
even with a grounded device you're depending on a chain of secure
grounds to keep your tool safe. I would also obtain a GFCI pigtail and
only run your power tools from that. They're required on all jobsites
I've been on and all the electrocutions I've studied have been from
workmen bypassing them.
Richard

Possible death. Replace the cord.

"Tim Zimmer" wrote in message
news:1116159867.dda65d992f7a2135aa9763b69aaf9081@b ubbanews...
Is it safe to operate an all alloy housing circular saw. My
15-year old industrial saw is reliable but the only thing aging
is the cord. The cord's insulation is cracking and deteriorating.
Last I'd check the ground wire is open but hidden from view.
What would be the hazards if I continue to use it?

Thanks

"spudnuty" wrote in message
oups.com...
It is quite an easy matter to replace the power cord and ground but
even with a grounded device you're depending on a chain of secure
grounds to keep your tool safe. I would also obtain a GFCI pigtail and
only run your power tools from that. They're required on all jobsites
I've been on and all the electrocutions I've studied have been from
workmen bypassing them.
Richard


A couple years ago I moved an outlet by putting a hand on each side,
contacting the hot with one and the neutral with the other. (I thought "the
other guy" had opened the breaker) I was rather surprised to be alive and
unhurt afterwards. I did some research and found out it is almost
impossible to get a lethal shock from 120v under normal circumstances.
Virtually all the electrocutions on record have been from 4000v or higher.

Accordingly, I am wondering about those fatal accidents you have studied.
If my understanding is incorrect, I certainly want to get it adjusted. (no,
I do not treat 120v casually; "almost impossible" means it is possible...)

In article 1116159867.dda65d992f7a2135aa9763b69aaf9081@bubba news,
says...

Is it safe to operate an all alloy housing circular saw. My
15-year old industrial saw is reliable but the only thing aging
is the cord. The cord's insulation is cracking and deteriorating.
Last I'd check the ground wire is open but hidden from view.
What would be the hazards if I continue to use it?

You would be risking a fatal electrical shock, should the saw
develop an internal insulation fault (as it very well could if it's that
old).

Replace the cord completely. If you lack the requisite skill
and/or tools to do so properly, you should take the unit to a
professional repair shop. Any place that repairs power tools should be
able to handle it.


--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"

"toller" wrote in message
...

"spudnuty" wrote in message
oups.com...
It is quite an easy matter to replace the power cord and ground but
even with a grounded device you're depending on a chain of secure
grounds to keep your tool safe. I would also obtain a GFCI pigtail and
only run your power tools from that. They're required on all jobsites
I've been on and all the electrocutions I've studied have been from
workmen bypassing them.
Richard


A couple years ago I moved an outlet by putting a hand on each side,
contacting the hot with one and the neutral with the other. (I thought
"the other guy" had opened the breaker) I was rather surprised to be alive
and unhurt afterwards. I did some research and found out it is almost
impossible to get a lethal shock from 120v under normal circumstances.
Virtually all the electrocutions on record have been from 4000v or higher.



IT ISN'T THE VOLTAGE! When I was in USN, they had studies showing deaths
from relatively low voltages. It's the amps, or more precisely the
milliamps, and where they travel. A certain milliamp current can be lethal
if it passes through the heart/chest area because it will cause the heart to
go into fibrillation, while a relatively high current may just cause the
heart to stop, but once it is removed the heart will restart on it's own. I
don't remember the exact numbers, but seems like it was around the 90-100
milliamp range that was lethal due to causing fibrillation.

--
Nahmie
The greatest headaches are those we cause ourselves.

"toller" wrote in message
...

A couple years ago I moved an outlet by putting a hand on each side,
contacting the hot with one and the neutral with the other. (I thought
"the
other guy" had opened the breaker) I was rather surprised to be alive and
unhurt afterwards. I did some research and found out it is almost
impossible to get a lethal shock from 120v under normal circumstances.
Virtually all the electrocutions on record have been from 4000v or higher.

Accordingly, I am wondering about those fatal accidents you have studied.
If my understanding is incorrect, I certainly want to get it adjusted.
(no,
I do not treat 120v casually; "almost impossible" means it is possible...)



Your heart operates on considerably less potential. You're betting that the
jolt won't find the proper pathway to interfere or stop it? Foolish wager.

Two in my experience on 120 Volts, but that's 50% of electrocution
fatalities I've had.

You would be risking a fatal electrical shock, should the saw
develop an internal insulation fault (as it very well could if it's that
old).

Replace the cord completely. If you lack the requisite skill
and/or tools to do so properly, you should take the unit to a
professional repair shop. Any place that repairs power tools should be
able to handle it.

I certainly agree that the cord should be replaced; but it is not
particularly dangerous. To get any shock, you would have to both short the
hot to the frame and break the neutral. While certainly not impossible, it
isn't likely. (Though I just threw out a 60 year old waffle iron with
exactly this problem; well actually it was shorted before the switch, so it
was like a broken neutral.)
Even then, the bigger danger is dropping a saw with a spinning blade than
electrocution.

My oven, like millions out there, has the neutral attached to the frame;
which is essentially a deliberate short. Unless the neutral is broken, it
is harmless. It is a foolish setup, and is now contrary to code, but you
would be hard pressed to find anyone hurt by it.

In article , "toller" wrote:

A couple years ago I moved an outlet by putting a hand on each side,
contacting the hot with one and the neutral with the other. (I thought "the
other guy" had opened the breaker) I was rather surprised to be alive and
unhurt afterwards. I did some research and found out it is almost
impossible to get a lethal shock from 120v under normal circumstances.

Once again demonstrating that you have _no_business_ giving electrical advice
to anyone. _Of_course_ it's almost impossible to get a lethal shock under
"normal circumstances" because "normal circumstances" don't include doing
stupid stuff like putting your hands across a live circuit. It's _abnormal_
circumstances that are dangerous, and it is indeed quite possible to receive a
fatal shock from 120V when something has gone wrong - like installing a stove
with its equipment ground connected to the circuit neutral conductor, as you
recently told someone to do.

And only an idiot would assume that "the other guy" had opened the breaker,
and not check first. Hell, I check before touching even when *I* am the guy
that opened the breaker - just to make sure I opened the right one.

If you work on your own wiring, I hope you live alone. I'd hate to see anyone
else's life jeopardized by your ignorance.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

On Sun, 15 May 2005 05:32:39 -0700, "Tim Zimmer"
wrote:

Is it safe to operate an all alloy housing circular saw. My
15-year old industrial saw is reliable but the only thing aging
is the cord. The cord's insulation is cracking and deteriorating.
Last I'd check the ground wire is open but hidden from view.
What would be the hazards if I continue to use it?

Either this is a troll or you are a moron. Take your pick.

don't remember the exact numbers, but seems like it was around the 90-100
milliamp range that was lethal due to causing fibrillation.

You are correct; 100ma is about the lethal threashold. But it is difficult
to get 100ma off 120v unless you are in sal****er.
Naturally adverse medical conditions, or just plain bad luck, will change
everything!

Glad I'm not the only one that does that.

"Doug Miller" wrote in message
...

Hell, I check before touching even when *I* am the guy
that opened the breaker - just to make sure I opened the right one.

"toller" wrote in message
...

A couple years ago I moved an outlet by putting a hand on each side,
contacting the hot with one and the neutral with the other. (I thought
"the other guy" had opened the breaker) I was rather surprised to be alive
and unhurt afterwards. I did some research and found out it is almost
impossible to get a lethal shock from 120v under normal circumstances.
Virtually all the electrocutions on record have been from 4000v or higher.

After a delivery truck hit a power pole and knocked down some power lines I
questioned the gentleman managing and keeping an eye on the crew repairing
the power lines. He indicated that 220 is more likely to get you as it
tends to hold on to you. The much higher voltage lines will more likely
throw you away.

On Sun, 15 May 2005 17:03:17 GMT, "CW" wrote:

Glad I'm not the only one that does that.

"Doug Miller" wrote in message
.. .

Hell, I check before touching even when *I* am the guy
that opened the breaker - just to make sure I opened the right one.

Neither of you are (the only one). I do, too. It's too easy to check,
and the potential consequences of not checking are too high.


--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

In article 1116159867.dda65d992f7a2135aa9763b69aaf9081@bubba news,
"Tim Zimmer" wrote:

Is it safe to operate an all alloy housing circular saw. My
15-year old industrial saw is reliable but the only thing aging
is the cord. The cord's insulation is cracking and deteriorating.
Last I'd check the ground wire is open but hidden from view.
What would be the hazards if I continue to use it?

Thanks

If a PaceMaker can keep your heart going with fractions of milliwatts
and low voltage, WTF makes you think that ANY electrical current is safe
or safer?

A ground is there to conduct possible power away from where it can cause
damage. To knowingly operate a metal tool without a proper ground is
just plain ****ing stupid. Nothing else sums it up better. You are a
****ing moron.

Or a troll.

I'm going with both.

I think the OP was trolling, judging by his lack of response. It looks
like he hauled in a whole netfull.

Bob

In article . com,
wrote:

I think the OP was trolling, judging by his lack of response. It looks
like he hauled in a whole netfull.

Bob

At the risk he was just an ignorant fool, I decided to respond anyway.
But I think you're probably right.

wrote in message

...judging by his lack of response.

I haven't found the time to work on the cord. I will now.

Someone please explain why do some modern factory drills, grinders
and saws get away without a ground plug?

(Here's an ignorant question) Is it true that I can receive a fatal shock if
I touch my skin from either neutral or hot and then ground? If so, then why
not replace the ground with a safer model which doesn't allow a shock?

Lastly, a hot or neutral short to ground shuts down my entire electrical
system. Is this the GFCI?

Thanks

"Tim Zimmer" wrote in message
news:1116192152.ce14365b22134300926898074b7384d5@b ubbanews...
wrote in message

...judging by his lack of response.

I haven't found the time to work on the cord. I will now.

Someone please explain why do some modern factory drills, grinders
and saws get away without a ground plug?
In addition to not having a metal case, they are double insulated..

(Here's an ignorant question) Is it true that I can receive a fatal shock
if
I touch my skin from either neutral or hot and then ground? If so, then
why
not replace the ground with a safer model which doesn't allow a shock?
You won't get much of a shock by simultaneously touching neutral and ground.
You can get a nasty shock by simulataneously touching the hot wire and
either the neutral or ground wires.

Lastly, a hot or neutral short to ground shuts down my entire electrical
system. Is this the GFCI?
No
Jim

I always double and triple check everything including a final check
with a non contact voltage tester. I've seen so many wierd things
working on clients electrical setups. You know the "What in the
F=2E....." moment and its another one for the books.
This sounds like a pertinent case:
http://www.cdc.gov/niosh/face/stateface/wi/93wi214.html
"A 45-year-old male electrician (the victim) was electrocuted when he
contacted an energized =BD-inch metal-cased electric drill.... There were
puddles of water on the cement floor of the work site. The drill was
connected to a temporary power pole by a series of three extension
cords, two of which were missing the ground pin.... The cords were
plugged into a ground fault circuit interrupter (GFCI) receptacle
mounted on the power pole. ... However, testing after the incident
disclosed the GFCI was inoperative, and the fuse box for the 120 volt
single phase 15- and 20-ampere receptacle outlets located at the power
pole contained two 40-ampere fuses."

Richard

In article ,
LRod wrote:

In home accidents in the U.S., one death in every hundred is the result
of an electrical shock from 110 or 220 volt sources.

Injuries from electric shock account for about 1000 deaths annually in
the United States and comprise about 5% of admissions to burn centres.
More than 60% of reported electrical injuries are due to electrocution
with 110- or 220-V current and most commonly result from failure to
ground tools or appliances properly or from using electrical devices
near water. Electrocution is the fifth leading cause of fatal
occupational injuries in the United States; 1% of household accidental
deaths are caused by electrical injuries.

The spectrum of clinical injury from accidental electrical shock ranges
from a transient unpleasant sensation after exposure to low-intensity
current to sudden death due to cardiac arrest. Clinical manifestations
are sometimes seen immediately after contact, but might not become
apparent until several hours after injury.

Source: Fish R. "Electric Shock. Part I: physics and pathophysiology",
Journal of Emergency Medicine, 1993, vol. 11, pp. 309-12.



--
Benoit Evans

In article t, "CW" wrote:
Glad I'm not the only one that does that.

"Doug Miller" wrote in message
.. .

Hell, I check before touching even when *I* am the guy
that opened the breaker - just to make sure I opened the right one.

In fact, I do more than that: I plug my tester into something that I'm sure
*is* live, to make sure it lights up when it's supposed to, before using on
something that I believe to be not live.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

So you're saying that toller's "research" had a few holes in it? Imagine my
surprise.

In article , Benoit
EVANS wrote:

In home accidents in the U.S., one death in every hundred is the result
of an electrical shock from 110 or 220 volt sources.

Injuries from electric shock account for about 1000 deaths annually in
the United States and comprise about 5% of admissions to burn centres.
More than 60% of reported electrical injuries are due to electrocution
with 110- or 220-V current and most commonly result from failure to
ground tools or appliances properly or from using electrical devices
near water. Electrocution is the fifth leading cause of fatal
occupational injuries in the United States; 1% of household accidental
deaths are caused by electrical injuries.

The spectrum of clinical injury from accidental electrical shock ranges
from a transient unpleasant sensation after exposure to low-intensity
current to sudden death due to cardiac arrest. Clinical manifestations
are sometimes seen immediately after contact, but might not become
apparent until several hours after injury.

Source: Fish R. "Electric Shock. Part I: physics and pathophysiology",
Journal of Emergency Medicine, 1993, vol. 11, pp. 309-12.




--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article , "toller" wrote:

don't remember the exact numbers, but seems like it was around the 90-100
milliamp range that was lethal due to causing fibrillation.

You are correct; 100ma is about the lethal threashold. But it is difficult
to get 100ma off 120v unless you are in sal****er.

Guess again, bozo.


--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article 1116192152.ce14365b22134300926898074b7384d5@bubba news, "Tim Zimmer" wrote:
wrote in message

...judging by his lack of response.

I haven't found the time to work on the cord. I will now.

Someone please explain why do some modern factory drills, grinders
and saws get away without a ground plug?

They're double-insulated. That means it takes *two* failures to make the case
live, instead of one.

(Here's an ignorant question) Is it true that I can receive a fatal shock if
I touch my skin from either neutral or hot and then ground? If so, then why
not replace the ground with a safer model which doesn't allow a shock?

If you mean, can you get a fatal shock from touching either hot or neutral,
while some other part of your body is touching ground, the answer is - Yes,
you can.

Equipment ground conductors are intended to ensure that no matter what happens
in the device you're using, its chassis cannot become live because the chassis
is connected to a true earth ground.

For maximum safety, use grounded tools, and plug them into a GFCI.

Lastly, a hot or neutral short to ground shuts down my entire electrical
system. Is this the GFCI?

The *entire* electrical system? Every circuit? That's a bit unusual... that
would suggest that your main breakers have tripped.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article ,
"toller" wrote:

don't remember the exact numbers, but seems like it was around the 90-100
milliamp range that was lethal due to causing fibrillation.

You are correct; 100ma is about the lethal threashold. But it is difficult
to get 100ma off 120v unless you are in sal****er.
Naturally adverse medical conditions, or just plain bad luck, will change
everything!

Where do you get this ? You state this stuff as fact? Do you have ANY
idea how irresponsible you are?

Shame on you!

In article , "Jim" wrote:

You won't get much of a shock by simultaneously touching neutral and ground.

Not necessarily so. It depends on how well you're grounded. If you touch
neutral and ground simultaneously, your body is providing an alternate path to
ground, in parallel with the neutral conductor. If you're standing in a puddle
on a bare concrete floor, you're providing a fairly low-impedance path to
ground. I wouldn't want to try the experiment.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article ,
LRod wrote:

On Sun, 15 May 2005 17:03:17 GMT, "CW" wrote:

Glad I'm not the only one that does that.

"Doug Miller" wrote in message
.. .

Hell, I check before touching even when *I* am the guy
that opened the breaker - just to make sure I opened the right one.

Neither of you are (the only one). I do, too. It's too easy to check,
and the potential consequences of not checking are too high.

Absolutely. The exact same concept applies to guns: "If there's even the
slightest doubt about whether it could be loaded, then *IT IS* until
proven otherwise."

If there's even the slightest doubt that a pair of wires might be hot,
then *THEY ARE* until proven otherwise.

Any other assumption in either case is stupidity on a scale you only
read newspaper articles about. Usually articles ending "Services will be
provided by insert name funeral home."

--
Don Bruder - - New Email policy in effect as of Feb. 21, 2004.
Short form: I'm trashing EVERY E-mail that doesn't contain a password in the
subject unless it comes from a "whitelisted" (pre-approved by me) address.
See http://www.sonic.net/~dakidd/main/contact.html for full details.

"Norman D. Crow" wrote in message
...

"toller" wrote in message
...

"spudnuty" wrote in message
oups.com...
It is quite an easy matter to replace the power cord and ground but
even with a grounded device you're depending on a chain of secure
grounds to keep your tool safe. I would also obtain a GFCI pigtail and
only run your power tools from that. They're required on all jobsites
I've been on and all the electrocutions I've studied have been from
workmen bypassing them.
Richard


A couple years ago I moved an outlet by putting a hand on each side,
contacting the hot with one and the neutral with the other. (I thought
"the other guy" had opened the breaker) I was rather surprised to be
alive and unhurt afterwards. I did some research and found out it is
almost impossible to get a lethal shock from 120v under normal
circumstances. Virtually all the electrocutions on record have been from
4000v or higher.



IT ISN'T THE VOLTAGE! When I was in USN, they had studies showing deaths
from relatively low voltages. It's the amps, or more precisely the
milliamps, and where they travel. A certain milliamp current can be lethal
if it passes through the heart/chest area because it will cause the heart
to go into fibrillation, while a relatively high current may just cause
the heart to stop, but once it is removed the heart will restart on it's
own. I don't remember the exact numbers, but seems like it was around the
90-100 milliamp range that was lethal due to causing fibrillation.

--
Nahmie
The greatest headaches are those we cause ourselves.

In low voltage the injuries are not usually from the electricity but the
secondary reaction. If you are on a ladder and have an electrical induced
muscle contraction it can throw you off the ladder killing you when you hit
the ground. Likewise if you are holding a screwdriver, you might stab
yourself in the eye/brain. (has happened) You could twitch and drill a hole
in your leg. If it's an electric chain saw .....Did you ever see a chain saw
injury? It gets right to the arteries and you bleed to death fast.
So a properly grounded power tool is safer and a GFI plug is better.

No doubt.

"LRod" wrote in message
...

Neither of you are (the only one). I do, too. It's too easy to check,
and the potential consequences of not checking are too high.

I've been an electrician for over 30 years and I can tell you it is
possible to get killed on 120V, but it is generally considered to be the
current that kills. As little as 100mA will cause the heart to
fibrillate regardless of voltage. It depends on the victims age,
thickness of skin (callouses insulate somewhat), how dry the skin is and
where the contact points are on the body. One older fellow I worked
with would routinely put his finger in light sockets to check for
voltage. His skin was old, dry and calloused and the current only
passed through his finger. Another who worked a circuit hot by lying on
a piece of insulating cardboard under a house died because his sweaty
neck touched a cold water pipe. Damp, thin skin, current through the
brain. Not a good combination.
GFI protection is a good thing and cheap insurance.

Old Sparky

toller wrote:
"spudnuty" wrote in message
oups.com...

It is quite an easy matter to replace the power cord and ground but
even with a grounded device you're depending on a chain of secure
grounds to keep your tool safe. I would also obtain a GFCI pigtail and
only run your power tools from that. They're required on all jobsites
I've been on and all the electrocutions I've studied have been from
workmen bypassing them.
Richard



A couple years ago I moved an outlet by putting a hand on each side,
contacting the hot with one and the neutral with the other. (I thought "the
other guy" had opened the breaker) I was rather surprised to be alive and
unhurt afterwards. I did some research and found out it is almost
impossible to get a lethal shock from 120v under normal circumstances.
Virtually all the electrocutions on record have been from 4000v or higher.

Accordingly, I am wondering about those fatal accidents you have studied.
If my understanding is incorrect, I certainly want to get it adjusted. (no,
I do not treat 120v casually; "almost impossible" means it is possible...)

"Robatoy" wrote in message
...
In article ,
"toller" wrote:

don't remember the exact numbers, but seems like it was around the
90-100
milliamp range that was lethal due to causing fibrillation.

You are correct; 100ma is about the lethal threashold. But it is
difficult
to get 100ma off 120v unless you are in sal****er.
Naturally adverse medical conditions, or just plain bad luck, will change
everything!

Where do you get this ? You state this stuff as fact? Do you have ANY
idea how irresponsible you are?

Any electrical book. Ever read one?
Electricians used to test for hot wires by touching it; a little tingle and
it was hot. Thats all it is, a little tingle. Certainly not a recommended
method with modern test equipment available, but not all that dangerous
since they used to get plenty of tingles.
Measure your resistance,and then figure out the associated current. It is a
lot closer to 0ma than to 100ma.

"Nog" wrote in message
...

"Norman D. Crow" wrote in message
...

"toller" wrote in message
...

"spudnuty" wrote in message
oups.com...
It is quite an easy matter to replace the power cord and ground but
even with a grounded device you're depending on a chain of secure
grounds to keep your tool safe. I would also obtain a GFCI pigtail and
only run your power tools from that. They're required on all jobsites
I've been on and all the electrocutions I've studied have been from
workmen bypassing them.
Richard


A couple years ago I moved an outlet by putting a hand on each side,
contacting the hot with one and the neutral with the other. (I thought
"the other guy" had opened the breaker) I was rather surprised to be
alive and unhurt afterwards. I did some research and found out it is
almost impossible to get a lethal shock from 120v under normal
circumstances. Virtually all the electrocutions on record have been from
4000v or higher.



IT ISN'T THE VOLTAGE! When I was in USN, they had studies showing deaths
from relatively low voltages. It's the amps, or more precisely the
milliamps, and where they travel. A certain milliamp current can be
lethal if it passes through the heart/chest area because it will cause
the heart to go into fibrillation, while a relatively high current may
just cause the heart to stop, but once it is removed the heart will
restart on it's own. I don't remember the exact numbers, but seems like
it was around the 90-100 milliamp range that was lethal due to causing
fibrillation.

--
Nahmie
The greatest headaches are those we cause ourselves.

In low voltage the injuries are not usually from the electricity but the
secondary reaction. If you are on a ladder and have an electrical induced
muscle contraction it can throw you off the ladder killing you when you
hit the ground. Likewise if you are holding a screwdriver, you might stab
yourself in the eye/brain. (has happened) You could twitch and drill a
hole in your leg. If it's an electric chain saw .....Did you ever see a
chain saw injury? It gets right to the arteries and you bleed to death
fast.
So a properly grounded power tool is safer and a GFI plug is better.

Even I can't argue with that...
I just get annoyed by the guys warning about the dangers of electrocution.

"Tim Zimmer" wrote in message
news:1116192152.ce14365b22134300926898074b7384d5@b ubbanews...
wrote in message

...judging by his lack of response.

I haven't found the time to work on the cord. I will now.

Someone please explain why do some modern factory drills, grinders
and saws get away without a ground plug?

They are double insulated. In normal use you should not be touching
anything that could be energized by a shorted hot.

(Here's an ignorant question) Is it true that I can receive a fatal shock
if
I touch my skin from either neutral or hot and then ground? If so, then
why
not replace the ground with a safer model which doesn't allow a shock?

You cannot get a shock from a neutral unless it is open. A closed neutral
(which it would be, unless it were broken) is such a good conductor that
virtually no current would go through you. Until a few years ago dryers and
stoves had the frames connected to the neutral. They are perfectly safe
unless the neutral is broken, and then you may be the best path to ground.

Lastly, a hot or neutral short to ground shuts down my entire electrical
system. Is this the GFCI?

No, that is an overload that trips the breaker. It takes either time or a
huge overload. It protects the wiring, not you!
A GFCI trips very quickly if the current going out on the hot is not exactly
the same as the current returning on the neutral. It protects you if you
touch the hot. It will not protect you if you touch the hot and the
neutral; but you would have to be a real cluck to do that! (please refer to
my first post above.)

Thanks

In article 1116192152.ce14365b22134300926898074b7384d5@bubba news,
Tim Zimmer wrote:
wrote in message

...judging by his lack of response.

I haven't found the time to work on the cord. I will now.

Someone please explain why do some modern factory drills, grinders
and saws get away without a ground plug?

Older style equipment has only one layer of insulation. A *single* failure
exposes the operator to electrical shock, unless the equipment is properly
grounded. With the grounding, it requires _two_ failures for possible
shock.

Newer gear is constructed in a style called "double insulated". It takes
_two_ separate "safety equipment" failures for the operator to be exposed
to a possible electrical shock.

By the nature of the 'double insulated" design, a failure of the second
insulation is much *less* likely than a failure of the 'grounding' system
in older equipment.

Hence safety is provided for in a "more reliable" manner. and the 'ground'
plug is not needed -- it doesn't provide any 'additional' protection.


(Here's an ignorant question) Is it true that I can receive a fatal shock if
I touch my skin from either neutral or hot and then ground?

Short answer: "Yes, you _can_ receive a fatal shock that way." This is not
to say that it _will_ be fatal in every instance. (see the 'long answer',
below, for all the gory details.)

Long answer (bear with me, it _does_ take a *long* discussion to cover all
the relevant matters) follows --

That's a *complicated* question. First off, what constitutes a "fatal"
shock depends on a _lot_ of things. The absolute minimal considerations
are 'how much _current_', and '*where* on the body'. applied directly
to heart muscle, a handful of milli-amps, which requires only a few volts,
is sufficient to cause 'catastrophic' problems.

Applied to the skin, away from the heart, what constitutes a 'dangerous'
level requires higher levels.

"How much" higher depends on a lot of things. The 'resistance' of skin,
etc. depends on a whole sh*tload of factors., but the biggest one is
how _dry_ the skin is, where contact is made. On a living being, "dry on
the surface" skin has a resistance of several thousand ohms. When skin is
damp -- sweaty, for one example -- the resistance decreases radically.
Can be as low as a few hundred ohms. _Below_ the surface of the body,
resistances are quite low. *especially* so for 'nerve fiber', which
runs *everywhere*.

Now, we have to take a digression into 'how electricity works'.
(note to purists: this description *is* somewhat simplified)

When you have two things "in parallel" connected to a source of electrical
power, There is always a flow of electric current through *both* of those
things. "How much" current flows through each thing is determined by the
resistance of that thing.

Note: 'in theory', "ground" is "ground", and is always at exactly the same
potential, regardless of location. In practice, it doesn't work that way.
"Ground" is a moderately lousy conductor, and you may get different levels
at different places.

In addition, the 'ground' and/or 'neutral' wires are *not* "perfect"
conductors. They are real-world devices, and have 'internal' resistance.
Depending on the size of the wire, and the length back to the transmission
point, this resistance can be significant. Any piece of wire, when you
connect to it at a point along its length, can be regarded as two resistors,
one representing the internal resistance from the beginning to where you
connect to it; the other from that connection-point to the other end of the
wire.

This means, among other things, that the 'neutral' wire _at_a_point_distant_
_from_the_power_source_, is *not* at the same 'ground' level as 'ground' at
the transmission point.

If you connect your body across the 'hot' wire, to ground (either 'earth
ground', or the 'ground' wire), you are placing yourself "in parallel"
with any other 'devices' (or 'loads') on that power feed. As those devices
have relatively high resistances (relative to 'just plain wire'), there
will be a considerable flow of current through your body.

If you connect your body across the 'neutral' wire, to ground (either 'earth
ground', or the 'ground' wire), you are placing yourself "in parallel" with
only the resistance of the 'return' part of that wire. This resistance is
comparatively _low_, and the current flow will be comparatively small.

From all this, it should be obvious that there is no simple nor easy means
of predicting "just how much" current _might_ flow through your body if you
get across the wires.

One more consideration to throw into the pot. There is no 'guarantee'
that the 'hot' and 'neutral' wires are _properly_ connected/identified.

What one _thinks_ is th 'neutral', may, in actuality, be the 'hot'.
It's not likely, but do you want to "bet your life" (literally!) on it?

The only "safe" way to work on electrical wiring is to:
0) assume that unprotected contact with the wiring *will* kill you.
(even if not _always_ true, you only get to be wrong ONCE )
1) disconnect it from the power supply
2) ensure that *nobody* can re-connect it without your OK.
(this is what "lock-outs" are for.)
3) test _after_ disconnecting to make sure there is no power present.
4) work on it *as*if* power was still present. (see rule #0)
(i.e. rubber gloves, insulated tools, only one wire at a time, etc.)

While that may _look_ excessively paranoid, it isn't.

Items 1,2,3 'appear' to describe a 'fool poof' system for ensuring safety.
Unfortunately,
"For every fool-proof system, there exists a *sufficiently*determined*
fool capable of breaking it."
applies.

that's why 4 *is* necessary.

If so, then why
not replace the ground with a safer model which doesn't allow a shock?

That's what modern "double insulated" tool design _does_.

That is *why* most tools are built that way today. grin

As for "doesn't allow a shock", well, the laws of physics are not subject
to repeal by the acts of man. ANY place there is a difference in electric
potential, there is the 'potential' for an electric shock. (Pun intended!)

The most one can do is engineer things so that getting a shock is "difficult".

Lastly, a hot or neutral short to ground shuts down my entire electrical
system. Is this the GFCI?

Probably.

GFCI detects _unbalanced_ current flow in the hot vs neutral wires.
This happens *only*if* there is 'some other path' for current to flow
through.

In the case of a 'hot to ground' short, assuming it is a true short (as
in approximately zero resistance), it will be a bit of a race between
the overload circuit breaker, and the GFCI, to see which trips first.

In the case of a 'neutral to ground' short, you do not have an 'overload'
condition, so the GFCI is the one shutting things down.

"Robatoy" wrote in message
...
In article ,
"toller" wrote:

don't remember the exact numbers, but seems like it was around the
90-100
milliamp range that was lethal due to causing fibrillation.

You are correct; 100ma is about the lethal threashold. But it is
difficult
to get 100ma off 120v unless you are in sal****er.
Naturally adverse medical conditions, or just plain bad luck, will
change
everything!

Where do you get this ? You state this stuff as fact? Do you have ANY
idea how irresponsible you are?

Shame on you!
-------
Actually, such information is available many places, including the EPRI book
on EHV power lines. The 100ma level is about the 0.5% probability level for
fibrillation. However, fibrillation is time dependent so that on prolonged
contact, the level drops (i.e. at a let-go current of 9-10ma it takes about
10 minutes to cause fibrillation). In many cases, design is based on a 5ma
level which is considered at or below the let-go level (not painless) for
both adults and children.
--
Don Kelly

remove the urine to answer

"Don Kelly" wrote in message
news:ahShe.1363374$6l.943940@pd7tw2no...


"Robatoy" wrote in message
...
In article ,
"toller" wrote:

don't remember the exact numbers, but seems like it was around the
90-100
milliamp range that was lethal due to causing fibrillation.

You are correct; 100ma is about the lethal threashold. But it is
difficult
to get 100ma off 120v unless you are in sal****er.
Naturally adverse medical conditions, or just plain bad luck, will
change
everything!

Where do you get this ? You state this stuff as fact? Do you have ANY
idea how irresponsible you are?

Shame on you!
-------
Actually, such information is available many places, including the EPRI
book
on EHV power lines. The 100ma level is about the 0.5% probability level
for
fibrillation. However, fibrillation is time dependent so that on prolonged
contact, the level drops (i.e. at a let-go current of 9-10ma it takes
about
10 minutes to cause fibrillation). In many cases, design is based on a
5ma
level which is considered at or below the let-go level (not painless)
for
both adults and children.

For what contact time is that 0.5% figure for 100a? Or is it just an
average figure for all contacts?