CSI electrical mistake

[metspitzer]

I was watching CSI. It is a great show.

Some guy falls 12 floors. His drill has been shorted and the ground plug has been cut.

CSI says the GFCI is useless without the ground plug. < false

[Anthony Diodati]

[Rick-Meister]

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&#39;s drill "shorted out" the GFCI would have popped.

In fact, the code allows GFCI&#39;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.

[gfretwell]

The GFCI might trip before the shock kills you but you can still fall off the ladder

[Jim Yanik]

metspitzer wrote in news: [e-mail]:

I like CSI and CSI Miami,but they are full of "mistakes". They are entertainment,but not factual.

(Florida doesn&#39;t have gun registration and our cars don&#39;t have front plates;MAJOR errors.)

[pipedown]

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&#39;t rely on anything I saw on them if I were a juror.

[metspitzer]

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 their GFCI.

[pipedown]

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.

[gfretwell]

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)

[Jim Yanik]

"pipedown" wrote in news:_9ydnayK4OUs09rVnZ2dnUVZ [e-mail]:

I&#39;ve read that jury candidates who watch CSI and like shows are often rejected for duty. They tend to expect evidence that is not possible or practical.

[Calvin Henry-Cotnam]

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&#39;s and 80&#39;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.

[John Gilmer]

In some cases that&#39;s true.

If his drill has exposed metal parts that were not connected to each other then a combination of faults could make one piece of metal "hot" and the other "neutral." If you use the drill you get the full 120 volts.

As an example, say you have a mostly plastic drill but the chuck and metal and a couple of the screws that hold it together are metal. You use the drill on something. You right hand is in contact with the screws that hold it together and you left comes in contact with the drill chuck. ZAP. And the GFCI would not trip.

If the ground was functional, the "cross" would likely cause a ground fault.

Don&#39;t get me wrong, what I outline isn&#39;t likely to happen. And many/most smaller electric drills only have a 2 wire plug.

** Posted from **

[Jim Yanik]

Calvin Henry-Cotnam wrote in news: [e-mail]:

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&#39;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&#39;s is only a few thousandths of an inch,not discernable with the naked eye.

They also show a CSI test-shooting a handgun into ballistic gelatin and the actual bullet depicted is a spitzer RIFLE bullet.

[Red Green]

Jim Yanik wrote in news:Xns9AB48A7946966jyanikkuanet@64.209.0.87:

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&#39;s for real.

[mr jones]

"production values" have increased ?

compared to what ?

we have the same folks bringing us that abomination "American Idol".

we have the same folks bringing us that &#39;technique&#39; of shaking the camera lens & jerking it around for no viable reason (thereby making a joke out of ENG helo&#39;s who have six figure "gyro stabilized image stabilization camera platforms".

we have the same folks bringing us shows that glorify beating the other guy senseless ("ultimate fighting").

and other assorted rubbish that "hollywood" puts out (and an equally moronic - and large - segment of society, buys into with enthusiasm).

[terry]

----------------------------------------------------------------------------------------------

Has anybody mentioned &#39;isolation&#39; transformers; particularly as one understands are used on UK construction sites?

Agree that having to drag around a heavy transformer or have longer extension cords can be a chore; having done it since 1956 in order to use my 230 volt British Wolf drill (purchased in 1953 and still going strong) here in North America on 115 volts 60 hertz!

Also have now added some carefully grounded 230 volt outlets above a work bench to avoid having to use the transformer, which also acts as an extension cord when not at a fixed location. Also bench saw etc. are 230 volts.

With the North American 3 wire 115-0-115 volt system the maximum voltage to ground is 115 RMS.

The UK construction site system appears to combine, for the use of hand tools, the best of two worlds?

It allows the use of generally cheaper and more universally available

115 volt tools on European mains voltage of 230 volts 50 hertz.

As understood, the construction site isolation transformer has a 230 volt input. The isolated secondary winding is half that at 115 volts and since it is closer to where the tool is used voltage drop not a concern.

But, particularly, the 115 volt secondary is centre tapped and THAT is grounded/earthed. So the maximum voltage to ground/earth, at the tool itself, is 115/2 = 57.5 volts RMS.

So the maximum &#39;peak&#39; voltage, per cycle, to ground, at the tool, is around 81 volts!

Compared to 230 x 1.41 = 263 peak volts for a hand held 230 volt tool, that&#39;s a lot safer?

Thinking of a possible variation of that system to use on our North American 115/230 volt domestic wiring. And or use a lighter weight auto-transformer to be able to plug my 230 volt drill into 115 volts more easily, anywhere.

[larry moe 'n curly]

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&#39;t that defeat the double insulation? I don&#39;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&#39;ve had two plug-in GFCI&#39;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.

[dpb]

larry moe &#39;n curly wrote: ...

Depends on how it is connected to the rest of the saw. If it is isolated, it still won&#39;t/can&#39;t complete a circuit.

--

[DerbyDad03]

209.0.87:

ed text -

re: Pay more attention to the hot chickies and their atire. That&#39;s for real

There are girls on that show? I gotta watch more carefully.

[Bill]

Such mistakes bug me, too, but TV writers are just that: writers. They&#39;re not engineers, physicians, judges, lawyers, chemists, physicists, gunsmiths, etc. Let&#39;s face it, a TV show based on real lawyers would be pretty boring - let&#39;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&#39;s clerk.