A GFCI does not measure short to ground. It measures a difference
between current in on the hot and current out on the neutral. So, the
second the guy's drill "shorted out" the GFCI would have popped.
In fact, the code allows GFCI's to be installed in place of a 2-prong
ungrounded outlet. However, the receptacle must either be labeled as
ungrounded, or the grounding port must be permanently sealed. They
figure that a GFCI in that case is still better than the old 2-prong
outlet, or someone installing a normal 3-prong outlet.
On Wed, 04 Jun 2008 21:14:52 -0400, email@example.com wrote:
You may be right. I have never experienced a shock from a device
plugged into a GFCI.
I have heard that a GFCI manufacturer has a video of a person jumping
into a pool with an electrical appliance that has been plugged into
What was useless without the ground prong was the main circuit breaker which
would have tripped as soon as it was plugged in otherwise. (in actual, the
GFCI would have beat the panel breaker to the trip)
GFCI trip current is designed to be low and fast enough to minimize the jerk
reaction from a shock. They recognize already that most shock injuries are
secondary from the reaction.
Lets all hear it for plastic power tools and double insulation. Eliminates
the need for a ground.
I have tripped a GFCI a couple times in a "shocking" fault. You
definately know you were shocked and you will jump.
(once was a defective tool, once was just a screw up, grabbed a wire I
thought was dead)
But a lot of double-insulated tools have a large exposed metal area
that the user will likely hold during operation. An example is the
metal gear case of a corded electric drill. Doesn't that defeat the
double insulation? I don't use double-insulated tools with 2-prong
cords, except in GFCI-protected AC outlets, and then I test the GFCI
immediately before use.
I've had two plug-in GFCI's fail, one by shutting off the current, the
other -- its replacement, by leaving the current on all the time. The
second replacement is still OK.
The motor's non-isolated metal shaft is in contact with a metal
bearing, either directly or through a metal gear, that's in contact
with the exposed metal. IOW if a motor winding shorts to the
armature, electricity can flow through the metal part of the case.
Yeah, CSI Miami is probably the worst of the 4 such shows on that network.
NCIS comes closest but still makes a few technical mistakes. I also find
all of them entertaining but wouldn't rely on anything I saw on them if I
were a juror.
I wonder how many of these "mistakes" are really mistakes and how many
are deliberate misinformation.
These shows do a surprising amount of research, given that this is just
entertainment. I had a relative who was the chief coroner in our province
in the 70's and 80's and his office was consulted a few times by the
producers of Quincy. Given that production values have increased since
that time, it reasonably follows that research has followed.
From that and the desire on the part of the producers and the networks
to avoid litigation, it seems reasonable to believe that deliberate
misinformation is sprinkled into scripts to prevent the accusation that
the show is a "how-to" manual on committing murder.
"Unusual or extreme reactions to events caused by negligence
IMO,the CSI:Miami "Florida gun registration database" is an attempt to bias
the unknowing public in favor of gun registration,as a tool for solving
crimes,when it hasn't been shown to be effective at that.
also what irks me is when a CSI holds up a bullet and says "9mm" without
measuring it,and the difference between .38,.380,.357 Magnum,and the
several 9's is only a few thousandths of an inch,not discernable with the
They also show a CSI test-shooting a handgun into ballistic gelatin and the
actual bullet depicted is a spitzer RIFLE bullet.
You guys are paying too much attention to the CSI Miami legal stuff. The
lab is lacking as there is never any duct tape to be seen. Pay more
attention to the hot chickies and their atire. That's for real.
Such mistakes bug me, too, but TV writers are just that: writers.
They're not engineers, physicians, judges, lawyers, chemists,
physicists, gunsmiths, etc. Let's face it, a TV show based on real
lawyers would be pretty boring - let's watch for an hour as they talk
on the phone, write letters, and get stuck in traffic driving to court
to hand in a motion to a judge's clerk.
The writers give general idea of what they want, but SFX guys are what
put these together and you would hope even if the script had direction
that said (visual shooting pistol, SFX: Rifle bullet in gelatin) they
would ignore it. Most of this is more related to the desire to use
something already paid for or stock than anything else.
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