Re: Use of Extension Cord


John Fields wrote:
> On Sun, 20 Nov 2005 14:57:48 -0000, "Peter Hucker" <no@xxxxxxxx>
> wrote:
>
> >On Sun, 20 Nov 2005 14:10:16 -0000, John Fields <jfields@xxxxxxxxxxxxxxxxxxxxx> wrote:
> >
> >> On Sat, 19 Nov 2005 22:28:45 -0000, "Peter Hucker" <no@xxxxxxxx>
> >> wrote:
> >>
> >>> On Sat, 19 Nov 2005 21:59:30 -0000, John Fields <jfields@xxxxxxxxxxxxxxxxxxxxx> wrote:
> >>>
> >>>> On Sat, 19 Nov 2005 17:50:44 -0000, "Peter Hucker" <no@xxxxxxxx>
> >>>> wrote:
> >>>>
> >>>>
> >>>>> Am I to assume here that US electrical cords are terrible compared to UK ones? All UK extension cords are rated at 13 amps (for 3kW devices) and have a 13 amp fuse in the plug so you cannot overload them. I assume in the US this would be 26 amps (ouch! THICK wire!).
> >>>>
> >>>> ---
> >>>> In the US we have a variety of extension cords available, the
> >>>> variety encompassing choices in both both wire size (AWG, BTW) and
> >>>> length.
> >>>>
> >>>> As such, we can choose what we need without being forced to buy an
> >>>> extension cord with more copper in it than we need
> >>>
> >>> Myself, and everyone I know, do not buy an extension cord then use it for one purpose for the rest of its life. They get moved around. You cannot predict what you will want to plug into it in the future. And they are so cheap you may aswell get the 13 amp ones.
> >>
> >> ---
> >> That's just foolish. If I need a ten foot extension cord for a
> >> floor lamp burning a 100 watt light bulb I certainly wouldn't need,
> >> or want, a 13 amp monster with a fuse in it when #18 zip cord and a
> >> 15 amp breaker in the service panel would be perfectly fine for my
> >> use.
> >
> >And your lamp would stay there forever would it? And you'd never want to plug something else in next to the lamp? Do you never move anything around in your house?
>
> ---
> Neither of those is to the point, which is that an extension cord
> with a 13 amp fuse in it is very nearly the same as an outlet with a
> 15 amp breaker in the service panel.
> ---
>
> >Besides, what you stated above is not safe - you have a FIFTEEN amp breaker for a ONE amp bulb?!?!?
>
> ---
> And a THIRTEEN amp fuse for a ONE amp bulb _is_ safe?
> ---
>
> >An how many amps can a #18 cord take?
>
> ---
> #18 has a resistance of 6.385 milliohms per foot, so with 15 amps
> flowing through it it'll drop:
>
>
> E = IR = 15A * 0.006385 ohms = 0.0957V ~ 0.1V
>
> per foot, and the power it'll dissipate will be
>
>
> P = IE = 15A * 0.1V = 1.5 watt per foot,
>
> hardly anything to get worried about, especially with thin
> insulation.
> ---
>
> >>>> and a fuse which,
> >>>> at 13 amperes, will be largely useless except in the case of a gross
> >>>> short at the load end of the cord.
> >>>
> >>> It's not useless at all. It prevents the extension cord from overheating, that's what the fuse is for. The fuse in the equipment's plug stops its cable catching fire. To put a fuse of the full capacity of the wall outlet off in the fusebox is stupid, because you will most likely plug a device into that outlet with a low power consumption and a thin cord, which is now not protected.
> >>
> >> ---
> >> By the same token, if I plugged my 100 watt lamp into the wall with
> >> your 13 amp fused monster extension cord, the thin wire in the lamp
> >> won't be protected and could easily set fire to something if, for
> >> some reason, 13 amperes was was allowed to flow through it for an
> >> extended period of time. If you want _real_ protection, fuse the
> >> lamp.
> >
> >Of course the lamp is fused. All UK mains plugs have fuses, by LAW.
>
> ---
> None of ours do, so I guess you're the pansies after all.
> ---
>
> >>>> Here, in the US, we've opted for a circuit breaker in the service
> >>>> panel which can be reset in case of an overload instead of a
> >>>> sacrificial fuse in the extension cord which _must_ be replaced if
> >>>> the extension cord is to be brought back to life.
> >>>>
> >>>> Makes more sense to me...
> >>>
> >>> Yes more modern houses here have circuit breakers instead of fuses in the fusebox, and people who are obsessed with safety, I just have fuses.
> >>>
> >>> My point is the circuit breaker or fusebox fuse doesn't know what an overload is. It breaks at the rating of the outlet, not the appliance and it's cord.
> >>
> >> ---
> >> And your 13A extension cord does essentially the same thing when
> >> supplying a low-amperage appliance with a 13A supply.
> >
> >Adding a 13A extension cord does not remove any protection which is already there by plugging the appliance in without an extension. The 13A fuse in the extension cord stops you plugging two 13A appliances into the end of it and melting the extension cord.
> >
> >>>>>> Check house insurance. Although the insurance company might
> >>>>>> deem that kind of cause 'negligence' by the policy !
> >>>>>
> >>>>> I don't think I've ever read any instructions, fineprint, terms and conditions, or policies in my life. I have more important and/or more interesting things to do with my time!
> >>>>
> >>>> Like posting about your ignorance?
> >>>
> >>> Ignorance of what?
> >>
> >> ---
> >> What does your smug: "I don't think I've ever read any instructions,
> >> fineprint, terms and conditions, or policies in my life. I have
> >> more important and/or more interesting things to do with my time!"
> >> sound like?
> >
> >It sounds like I realise they are a waste of time. Instructions are for people who don't have a clue how something works.
>
> ---
> It sounds to me like you're a conceited idiot. Instructions are
> what you read in order to operate something properly, no matter how
> much of a clue you think you might have.
> ---
>
>
> >>> Ignorance of
> >>> How dangerous American electrical systems are?
> >>> They are more or less exactly how we used to do things. Now it's illegal here.
> >>
> >> ---
> >> All that means is that you've taken a step "forward" into more
> >> dangerous territory. We still have 240 V coming into every
> >> household for use by high-power appliances (A/C, clothes dryers,
> >> water heaters, electric ranges, and the like, but we also have the
> >> transformer secondary's center tap coming in as well. That allows
> >> us to use a much safer 120V for all our other needs. It's also
> >> cheaper to make smaller appliances that run on 120V since, for
> >> example, 120V transformer primaries need only be wound with half the
> >> number of turns as a 240V transformer for the same output voltage.
> >
> >I wasn't talking about voltage. I was talking about your location of fuses, see above.
>
> ---
> You were talking about safety, and regardless of where the fuses are
> located, 120V is inherently safer that 240 in case of a shock.
> ---
>
> >But since we're on voltage, it's a lot more convenient to have every outlet the same, I can plug anything into any socket.
>
> ---
> All our 120V sockets are the same, so so can we. Our 120V sockets
> are different from out 120V sockets for obvious reasons, but they're
> all the same also, so that's not a problem either.
> ---
>
> >Just a minute, does that mean you can use a 240V appliance you bought over here when you go back to the US? I thought you were 110V only.
>
> ---
> Probably 90-95% of the US is 120/240, so yes, of course we can. The
> only problem is the difference in frequency, you being on 50Hz and
> us being on 60, but that often turns out not to be a problem at all.
>
> Unfortunately for you, if you buy 120V appliances here and take them
> back with you you'll be out of luck unless you buy a 2:1 transformer
> to run them on.
> ---
>
> >>>>>> Another mistake can be plugging too many devices into the one extension
> >>>>>> cord, not of adequate rating/size to carry the total amount of electric
> >>>>>> current!
> >>>>>
> >>>>> Er..... FUSE anyone? Don't tell me they have unfused extension cords in the US? And I thought you chose 110 volts for SAFETY......
> >>>>
> >>>> ---
> >>>> Whatever the reason, I can guarantee that if you pinch across your
> >>>> 240 mains with both hands at the load end of your fused extension
> >>>> cord and you take a hit across your chest and I do the same at the
> >>>> end of my 120V unfused extension cord I'll have a better chance of
> >>>> surviving the hit than you will.
> >>>
> >>> Because you have circuit breakers. We do too. I don't as it's an old house and I haven't changed them. This has absolutely nothing to do with whether the extension cord is fused or not. If I removed the extension cord fuse, I would be no more likely to survive.
> >>
> >> ---
> >> You don't have much of an attention span, do you?
> >>
> >> You broached the subject of our choosing 120V for reasons of safety,
> >> and I was pointing out that whether we did or not, 120V is
> >> _inherently_ safer than 240V. The extension cord, circuit breaker
> >> and all the rest of it have nothing to do with it, since the fact
> >> remains that a 240V hit is harder than a 120V hit. Four times
> >> harder for the same body resistance and same contact time if you
> >> consider the power being dissipated in the body. Also, 240V will
> >> cause much more violent muscle contraction, leading to the greater
> >> likelihood of secondary injury.
> >
> >The reason I mentioned the fuse is thatyou did - "end of your fused extension cord".
>
> ---
> What are you, a child? At this point we're discussing safety and
> whether a line is fused or not makes no difference in terms of being
> shocked to death. Do you think that the 13 amp fuse in the
> extension cord is going to blow before you're dead if you take a hit
> across your chest?
> ---
>
> >Anyway 240V may be more dangerous, but we can have much thinner cables. And it ain't as dangerous as you make out anyway.
>
> ---
> You can have cables with smaller diameter conductors for the same
> load dissipation, but you need thicker insulation.
>
> And, it's not "may be more dangerous", it's "_is_ more dangerous",
> so stop trying to trivialize the difference.
> ---
>
> >>>>>> All seems rather too obvious to ask? But I've seen some horrors!
> >>>>>
> >>>>> I've been electrocuted 6 times at proper mains voltage (240, not your pansy 110), and I'm still alive.
> >>>>
> >>>> ---
> >>>> Once should have been enough to keep the other five from happening
> >>>> so, more than likely, there's a Darwin Award in your future...
> >>>
> >>> Electrocution occurs when you have a weak heart.
> >>
> >> ---
> >> No, electroction occurs when you are shocked to death as was pointed
> >> out by another poster.
> >>
> >> It's also entirely possible to have a fine heart but to die from
> >> fibrillation caused by even a moderately weak shock.
> >
> >Just doesn't happen. Are you suggesting I have an unusually strong heart?
>
> ---
> No, an unusually thick head.
> ---
>
> >>> In fact statistics show that most injuries and deaths occuring from electrocution occur due to >secondary accidents.
> >>
> >> ---
> >> Then the cause of death wasn't electrocution.
> >
> >Read the link I posted to the other pedant.
>
> ---
> Why? I see that you like to play fast and loose and, when you make
> a mistake, refuse to own up to it and, instead, cast aspersions on
> who caught you. You're a dishonest little prick.
> ---
>
> >> Electric drill electrocutes you and you fall off your ladder, etc.
> >>
> >> ---
> >> In that case the cause of death (if you weren't dead before you hit
> >> the ground was a broken neck, a concussion, whatever. But _not_
> >> electrocution.
> >
> >The CAUSE of death was a faulty appliance.
>
> ---
> No, the cause of death was a broken neck.
>
> The reason for the accident was a faulty appliance. Big difference.
> ---
>
> >If I pushed you off a ladder and you broke your neck, you seem to be saying it wouldn't be called murder.
>
> ---
> That's a totally different situation and has nothing to do with what
> we're discussing, but you inserted it in order to try to obfuscate
> the fact that you were wrong. More bull*** diversionary tactics.
> ---
>
>
> >> To belabor a point, since being shocked by 240V is a much more
> >> physically dramatic event than being shocked by 120V, it's much more
> >> likely that you'll be thrown off the ladder by a 240V drill than by
> >> a 120V one, which bring us back to the _fact_ that 120V is safer
> >> than 240V.
> >
> >Who uses corded drills anyway?
>
> ---
> More bull*** diversionary tactics.
>
> _I_ use corded drills, outdoors, all the time and haven't been
> electrocuted yet.
>
> --
> John Fields
> Professional Circuit Designer

May I ask a question here? The British fused plugs, are these the 2
cylindrical prongs about 1 inch apart with a ground tab? I've never
been to England to see what is really used but is the point of that tab
to be a safety ground? The plugs I've seen on equipment from the UK
don't connect the ground first but last. Or is it NOT for safety
purposes? American 3 wire connectors have a safety ground that connects
before the power and neutral get connected.

So far I have seen nothing about GFI outlets. Are those used in the UK
like in the US? Even old houses require retrofit to GFIs in the
kitchens and bathrooms when the house gets sold ( at least in
California ). Supposedly you can toss a lamp on a GFI circuit into the
bathtub and not kill the bather though I must cofess to being chicken
to give it an actual test. Anyway, carry on the debate.

Glenn Gundlach

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