# Electrical people, I have a question for you **URL:** \ **Category:** Factual Questions\ **Created:** [April 6, 2001, 4:53am UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030 "2001-04-06T04:53:40Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![wolfseyn](https://avatars.discourse-cdn.com/v4/letter/w/97f17d/32.png) [@wolfseyn](https://boards.straightdope.com/u/wolfseyn)\ **Post date:** [April 7, 2001, 11:42pm UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/21 "2001-04-07T23:42:24Z")
> [@](#): > > \*Originally posted by handy \* > \*\*techchick68, if you can get a volt meter (they are cheap) see how much voltage you have at your outlets. There might be too much voltage. > > One time some of mine were putting out 124 volts! The elec people came out in an hour & corrected it though. \*\* Use one hand when you do this. Stick your other hand in your pocket. This prevents current from traveling through your heart. ---
**Author:** ![bare](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bare/32/471_2.png) [@bare](https://boards.straightdope.com/u/bare)\ **Post date:** [April 8, 2001, 11:37am UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/22 "2001-04-08T11:37:31Z")
> [@](#): > > _Originally posted by Chronos \* > \*\*Another relevant question: What do you usually do when a fuse burns out? Many folks[sup]_[/sup] will go out and buy a higher-rated fuse, or even short out the fuse entirely (!) > \*\* Hope you’ve had the problem **Professionally** looked at by now, all this help is starting to sound scary. I know we live in the sticks here Chronos, but if my place still had a fused panel, I’d be looking for a replacement. ---
**Author:** ![excitableboy](https://avatars.discourse-cdn.com/v4/letter/e/c4cdca/32.png) [@excitableboy](https://boards.straightdope.com/u/excitableboy)\ **Post date:** [April 8, 2001, 5:16pm UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/23 "2001-04-08T17:16:43Z")
It should be mentioned that if your space heater pulls 12.5 amps, you technically need a 20 amp receptacle. This is because your disconnect must be derated to handle no more than 80% of it’s rated load. In this case, your receptacle and plug combination is your disconnect. I know that this was discussed by someone earlier with regard to wire size. Also, if you use the pass throughs on other receptacles on the same circuit ahead of the one serving your space heater, they also need to be 20 amp receptacles, as the pass through wiring is generally (but not always)the same as the receptacle wiring. ---
**Author:** ![excitableboy](https://avatars.discourse-cdn.com/v4/letter/e/c4cdca/32.png) [@excitableboy](https://boards.straightdope.com/u/excitableboy)\ **Post date:** [April 8, 2001, 5:19pm UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/24 "2001-04-08T17:19:12Z")
I mean, the receptacle rating is generally the same as the pass through wiring rating. (always preview your replies, kids) ---
**Author:** ![JoeyBlades](https://avatars.discourse-cdn.com/v4/letter/j/a87d85/32.png) [@JoeyBlades](https://boards.straightdope.com/u/JoeyBlades)\ **Post date:** [April 9, 2001, 2:21pm UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/25 "2001-04-09T14:21:33Z")
TBone: > [@](#): > > The only reason that an unused outlet would be hot is that it is serving as a high-resistance connection to the outlet that is in use. Actually, this has not been established, as far as I can tell. There are a number of more likely scenarios than faulty wiring. The heater itself being the highest probabillity (as mentioned earlier by wolfseyn). Of course, these mundane causes are not nearly as intersting as the possibility that techchick’s house might suddenly burst into flames because some electrician violated code or some outlet has gone out of spec… [sarcasm] handy: > [@](#): > > One time some of mine were putting out 124 volts! The elec people came out in an hour & corrected it though. 124V is not outside the normal range. The power going into your house is not that well regulated (from a supply voltage standpoint). I’m surprised that you got a service call out of that… unless they charged you for it. [wink] ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [April 9, 2001, 3:03pm UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/26 "2001-04-09T15:03:32Z")
“124V is not outside the normal range. The power going into your house is not that well regulated (from a supply voltage standpoint). I’m surprised that you got a service call out of that… unless they charged you for it. [wink]” No charge. However, when I took a bath I got shocked a lot when I touched the faucet. This of course needed to be corrected. They did this by regrounding everything, free. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [April 9, 2001, 4:48pm UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/27 "2001-04-09T16:48:45Z")
> [@](#): > > \*Originally posted by handy \* > \*\*“124V is not outside the normal range. The power going into your house is not that well regulated > (from a supply voltage standpoint). I’m surprised that you got a service call out of that… unless > they charged you for it. [wink]” > > No charge. However, when I took a bath I got shocked a lot when I touched the faucet. This of course needed to be corrected. They did this by regrounding everything, free. \*\* There are actually two things we might be talking about here: **differential** voltage and **common-mode** voltage. The differential voltage is nominally 120 VAC, and is primarily “set” by the step-down transformer (winding ratio and other factors). The common-mode voltage should also be 120 VAC _if the center tap on the transformer is well grounded to the earth next to your house_. If it is _not_ well-grounded to the earth, the common-mode voltage could float above 120 VAC. And if the transformer’s center tap is not grounded at all, you could have a very dangerous situation in that the common-voltage _could_ theoretically float up to the primary voltage (thousands of volts) while the differential voltage remains at a nominal 120 VAC. But what usually happens is this: the center wire is not grounded at your house, and you end up getting a common-mode voltage of just a few volts above 120 VAC. Why? Because, chances are, two or three neighbors are operating off the same transformer, and the transformer’s center tap is being grounded at _those_ locations. (There is a potential drop between the ground at your house and the ground at your neighbors’ homes.) ---
**Author:** ![JoeyBlades](https://avatars.discourse-cdn.com/v4/letter/j/a87d85/32.png) [@JoeyBlades](https://boards.straightdope.com/u/JoeyBlades)\ **Post date:** [April 9, 2001, 7:13pm UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/28 "2001-04-09T19:13:28Z")
> [@](#): > > The differential voltage is nominally 120 VAC, and is primarily “set” by the step-down transformer (winding ratio and other factors). There are other “other factors” that affect the voltage regulation to your home: load balancing (what your neighbors are up to), resistive shorts (from trees), etc… Most power companies will only guarantee to meet the CSA Standard C235, which allows a tolerance of 108V to 125V (106V to 127V in the Canadian equivalent standard, CAN3-C235-83)- so even the differential voltage of 120V is “nominal”. My point is, even if everything is hooked up right, you may not see a constant 120V - on the other hand, handy’s situation certainly sounds abnormal… though I can’t, for the life of me, figure out how you get shocks from grounded pipes… ---
**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\ **Post date:** [April 10, 2001, 12:49am UTC](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030/29 "2001-04-10T00:49:32Z")
Many a house has burned down because of aluminum wiring. Outlets today are made with special connections that have AL/CU stamped on them. These are OK for either aluminum or copper. I \*\* think\*\* all of todays outlets are AL/CU compatable but I would look for sure. Since the house is so new I’ll bet it doesn’t have aluminum wiring. [Previous page](https://boards.straightdope.com/t/electrical-people-i-have-a-question-for-you/61030.md?page=1)