Lawrence, On Mon, 15 Sep 2003 10:30:19 -0500, llile@SALTONUSA.COM wrote: > In the US we have two-wire (no grounded prong) 14 amp rated extension > cords with 3-way multitaps on the end, but no fuse. > > Firemen call these "Extinction cords". Thanks, I think you have just confirmed my point! :-) > Back when I inspected wiring I found a fraternity house where every room > was wired with a dozen of these strung in series in most every room. Some > of the cords also ran into the attic, where the residents had cut holes in > the ceiling and created loft rooms with only one exit. All the cords were > stapled onto the walls with metal staples, some of which penetrated the > insulaton and were live. "Don't touch that one" the residents said. Try > plugging three of these together and powering a few toasters and hotplates > ( as the residents were doing) and see how hot the cord gets. It's a > wonder the building wasn't on fire when I got there. I presume they were studying electrical engineering? :-) > Why are Extinction cords still legal? I caught my family with one and > snipped it into little pieces. They can use a heavy duty grounded cord > like I use in my shop, or a power tap. A power tap with a circuit breaks > and a grounded cord is a lot safer. Not sure what you mean by a "power tap" as opposed to an extension cord - but I am amazed that the cords you describe are legal. In Britain there is only one domestic item that *must* conform to standards for it to be sold, and that's the plug. It must meet BS1363 and as I said, it is fused, and therefore protects the cable to the appliance, and the standard includes creepage and clearance distances, inability to contact live pins when it is partially-inserted in the socket, presence of an effective cable-grip, and inability to dismantle while plugged in, among other things! Our plugs are usually rewirable, although moulded-on plugs are making more of an appearence when supplied with appliances, but they still have to conform to BS1363 and have a cartridge fuse which you can only change when it's unplugged. > The US mains wiring system is the most dangerous by design. 60 Hz is > the perfect frequency to defribulate the heart. 120 volts is the perfect > voltage to make your arm muscles grab on reflexively, but won't knock you > away. Good grief, I'd never heard this! I always thought our 240V / 50Hz was inherently more dangerous. I have had a few mains shocks (one from a frayed cable when I was about 7 years old - it threw me back!) and they are no fun at all. I also know of three people killed by it, the only incident whose details I know involved standing in a garden pond and accidentally cutting the cable to the fountain-pump, but I suppose being thrown back doesn't do a lot when you're stood in water. Very sad, all three cases. >Half the housing stock in the US still has ungrounded wiring in all > the walls, with two prong outlets, perfectly legal because it is > grandfathered in. I presume you mean that as it's already like that, you don't have to change it? (My staircase wouldn't be allowed to be built nowadays, but I don't have to change it). I was appalled to find that when I visited a new friend's house in New York, that the sockets didn't have earthing, but 2-to-3 pin convertors were plugged in (often with multi-way extensions connected) with a tiny earth lead *sometimes* clamped by one of the mounting screws. I went with her to Home Depot and bought a box of new sockets (Al/Cu compatible - what is different from Cu-only, I wonder?) and set to replacing the most important sockets for her. (I wonder if someone is going to say I shouldn't have done so as I'm not a NYC-acredited electrician? :-) I take it that it's usual for the steel conduit to form the earth conductor in these installations? Because there certainly wasn't a wire to do the job! >Most houses over 50 years old have a dozen code > violations in the main breaker box alone. Most houses over 80 years old > still have knob-and-tube wiring with the insulation fallen off. I used to live in a house built in 1837, and the wiring (not that old of course - there was evidence of gaslights under the wallpaper) was rubber insulated. I don't know how old it was, but it was well perished! It was fine as long as you didn't disturb it, but as soon as you tried to, for example, change a light switch, the insulation fell away, and you were in for a session under the floor, replacing the section of cable. There was also evidence of the old bell-pull system under the floor, and when I found it I realised why a pivoted L-shaped lever is called a bell-crank! :-) So back to the plot: Howcome they aren't making it illegal to have dangerous wiring in US houses? I'd have though the electricians would be lobbying the government for it, so they'd have a sudden upturn in business! They could take a leaf out of the UK car windscreen industry's book... it's now illegal to have a crack of more than a certain size in particular parts of the windscreen, so a stone-chip can now mean an expensive replacement! Cheers, Howard Winter St.Albans, England > -- Lawrence Lile > Senior Project Engineer > Toastmaster, Inc. > Division of Salton, Inc. > 573-446-5661 voice > 573-446-5676 fax > > > > > John Ferrell > Sent by: pic microcontroller discussion list > 09/13/2003 09:38 PM > Please respond to pic microcontroller discussion list > > > To: PICLIST@MITVMA.MIT.EDU > cc: > Subject: Re: [OT:] good power distribution > > > Most of the wall plug circuits have 15 amp circuit breakers and 14 or 16 > gage wire. Any way you get to15 amps trips the breaker. > > I am not aware of it being any hazard. > > John Ferrell > 6241 Phillippi Rd > Julian NC 27283 > Phone: (336)685-9606 > johnferrell@earthlink.net > Dixie Competition Products > NSRCA 479 AMA 4190 W8CCW > "My Competition is Not My Enemy" > > > ----- Original Message ----- > From: "Howard Winter" > To: > Sent: Friday, September 12, 2003 2:05 AM > Subject: Re: [OT:] good power distribution > > > > (OT tag added) > > > > On Fri, 12 Sep 2003 20:17:40 +1200, Hopkins wrote: > > > > > House just down the road had a fire in there lounge > > because a multibox got > > > over loads :-{ > > > So be careful. > > > > This had never occurred to me before - the American > > wiring scheme, where the only fuses/breakers are at the > > distribution box, means that there's nothing to stop you > > adding dozens of multi-way socket-strips to each other, > > and plugging into a single wall socket. So nothing > > technical stops an overload until you exceed the whole > > circuit's rating - have I go this right? > > > > (As a matter of interest, in Britain we have fuses in > > each plug, with a maximum of 13A - approximately 3kW - > > so you can't exceed this via any single socket because > > extension leads/multiway strips have a fuse in their > > plug too). > > > > Cheers, > > > > Howard Winter > > St.Albans, England. > > > > -- > > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > > > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.