mark (10/06/82)
While we're on the topic of electrical outlets, I have a question for any electricians on the net. We bought two lamps a few months ago. The vanilla kind with a 3 way switch, a lampshade, etc, that you put in your living room. These lamps have polarized plugs on them. This makes it very hard to plug them into an extension cord that isn't polarized. My question: why are lamp cords polarized? Is there any possible safety gain? Or are all plugs being made today polarized? I know you can buy polarized extension cords now at your favorite grocery store, but we have lots of perfectly good unpolarized cords. It seems like a plot to make us buy new extension cords. Mark
jcw (10/07/82)
Yes, there's a safety gain... as well as the obvious irritation gain. One side of your power line (called the 'neutral') is grounded at one or more points. Therefore, if you are holding the other side of the power line (commonly called 'hot'), you can complete the circuit by grouding yourself to any convenient ground. Those who have experienced this know there's nothing like it... In a lamp, the only likely place you MIGHT contact either side of the power line is when replacing the light bulb. At such a time, it would be SAFER if the hot wire were connected to the bottom of the socket and the neutral to the part you screw the bulb into. For that marginal safety gain, I'd spend fifty cents and buy a non-polarized plug for my lamp. However, I would leave the polarized plug on my television set.
burris (10/07/82)
#R:unc:-404400:ihlpb:6600007: 0:529 ihlpb!burris Oct 7 1:47:00 1982 It is not a plot that you should but polarized extension cords. The reason these came about was an attempt to prevent polarity differences between appliances, thus preventing you from ending up with 110 volts between you and another appliance. In many cases this is not a problem because neither side of the power line is connected to the chassis of the appliance. If you mix polarized and non-polarized you should be aware of what you are doing, it could present a shock hazard. Dave Burris ihlpb!burris BTL - Naperville
burris (10/07/82)
#R:unc:-404400:ihlpb:6600008: 0:703 ihlpb!burris Oct 7 13:15:00 1982 You are correct in your statement about polarized plugs, however, as a technician, one of the first things I learned about shock hazards is to remove the power before servicing. In the case of the burned out bulb this would require that the lamp be unplugged before replacing the bulb. Most of us have been around have been around electricity so much that we take for granted the amount of safety envolved. By the way, a house correctly wired with 3-wire outlets should not have the ground and the neutral connected. The neutral comes from the power company and the ground is supplied by the homeowner, usually by driving a copper stake into the ground. Dave Burris ihlpb!burris BTL - Naperville
rwc (10/08/82)
All of this talk about polarized plugs reminds of the time I was taking an after hours TV repair course at work. The instructor was very careful about telling all of the whys and wherefores of polarized outlets and plugs, and how it was very important to maintain this safety feature, especially when dealing with TV sets where the chassis is connected to one side of the line. Naturally, after this long spiel, he plugged the set into the polarized socket, only to find out that the electricians had wired the socket backwards. Fortunately, no one got zapped. Moral of the story: Unless you wired the outlet youself, and you know what you're doing, DON'T assume that whoever put it in did it right. If you have something that really needs a polarized plug (lamps don't), check it out before plugging it in.