AC reverse polarity problems? |
Question And Answer Category: Electrical |
Question: |
| Dear Blankhelp Team, I was told by a coworker that he had an ac reverse polarity problem? What are ac reverse polarity problems? I just nodded and asked a few questions, but seemed that he really didn't know what reverse polity truly was, and why it was a problem. Is this serious? Can ac reverse polarity problems kill? Should I have my house checked? How do you check for ac reverse polarity problems? Thank you, not a fan of working with electricity, so this kind of bothers me, and I ramble on. Todd |
Our Advice and Answer: |
| Hell Todd, Calm down. No need to panic. AC reverse polarity problems are real, and can happen. Let us give you some background. Newer residential receptacle outlets have three holes, for plug prongs. The single round one is for the ground, and the other two are for actual electricity flow. One of these two prongs is referred as the 'hot', the supply of electricity. The other is the 'neutral' or the 'return'. The hot can shock. The neutral, on a properly wired system, shouldn't be able to shock. So, many appliance manufactures who don't include a grounding prong (the round hole), make sure that the supply of electricity only applies in a certain direction. Example, a metal lamp. Some bulb holders are metal, and when you change the bulb you see a tiny spot (contact) at the base of the socket holder that touches the center of the bulb socket. If you turn on the electricity, the flow of current should be from the tiny spot, through the bulb and out the socket base. Should the polarity be reversed, then the current would flow from the socket base, through the bulb, and out the tiny spot at the bottom. Now if turn off the lamp, the socket holder can remain energized, the switch only controls current flow to the tiny spot (contact). So if you were to touch the socket and 'grounded' yourself, you could have electricity flow through you. See, if you have a choice, you want the smallest part of the lamp to ever be hot. This is why some prongs are fatter than others, so you can't install a plug in reverse. Now if your receptacle outlet has a reverse polarity problem, installing the plug correctly still applies a reverse polity on your appliance, this case the lamp, now you are at risk of shock. So an ac reverse polarity problem can be dangerous. Now for testing, many hardware stores sell receptacle testers. These are small handheld devices, about $10, and has three or more lights on it. By plugging in the circuit tester and idenifiying the lights, you can tell if your outlet has an ac reverse polarity problem. If you find an outlet with an ac reverse polarity problem, then that outlet needs to be rewired. This doesn't require a lot of work, assuming the service panel is wired correctly. Just that the receptacle needs the hot and neutral supply wires swapped. All this can be done by anyone, but here at BlankHelp we feel that only qualified electricians should work on electrical circuits. The circuit tester is designed for home owners, and useful enough that electricians use it, but leave the wiring to the professionals. So, ac reverse polarity problems can be dangerous, can be tested for, and can be fixed easily. As for having to test your house, the problem doesn't seem to exist with newer homes, but with older ones. It seems more and Do It Yourself'ers are feeling comfortable with working with electricity, and they do their own work without knowing the impact of what they are actually doing. This causes for wires to become swapped, and a reverse polarity problem could be generated. Hope this information can better help you figure the course of action on your own house, and understand how your coworker was smart to fix his ac reverse polarity problems. Sincerely, The BlankHelp Team |
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