# Is there an electrician in the house? (My house is not about to burn down or anything.) **URL:** \ **Category:** Factual Questions\ **Created:** [October 27, 2022, 3:26am UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850 "2022-10-27T03:26:36Z")\ **Posts on this page:** 9\ **Page:** 3
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [October 29, 2022, 12:16am UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/41 "2022-10-29T00:16:53Z")
> [@md-2000](#): > > 2.5 ohms per 1000 feet is negligible in a residential wiring. Not so negligible that you can’t measure it. If the wire resistance ends up as 0.2 ohms, that’s a 3 volt drop @ 15 A, or 2.5%. I’m not sure what a receptacle adds. It’s surely higher with a backstab connection than screw-on. And higher yet as a bit of corrosion sets in. ---
**Author:** ![Bob\_Blaylock](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_blaylock/32/3235_2.png) [@Bob\_Blaylock](https://boards.straightdope.com/u/Bob_Blaylock)\ **Post date:** [October 29, 2022, 12:26am UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/42 "2022-10-29T00:26:33Z")
> [@md-2000](#): > > I have to accept the electrical people know what they are doing, but it seems to me if you have a failure in a receptacle then any failure is a problem - it should not be constructed such that you don’t notice there’s a problem. > > If your neutral is disconnected then I don’t see the circuit working for that outlet or any down-chain. Using pigtails so the problem is not apparent just seems a bad idea. You want to notice wiring issues, the sooner the better. There’s a difference between a failure that results in something just not working, and a failure that can kill someone. That’s the difference between a failure in the hot connection, to downstream receptacles, and a failure in the ground or neutral connections. If the hot connection fails, then you just don’t have power. If the ground or neutral fail, then you have a significantly-increased risk of someone getting electrocuted. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [October 29, 2022, 12:39am UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/43 "2022-10-29T00:39:46Z")
> [@md-2000](#): > > Hence the question - what should a receptacle add? This guy does some testing of connectors: [![](https://img.youtube.com/vi/katwxG_1cqM/hqdefault.jpg "Comparing Wire Connector Resistance - Wago vs. Twist-on Wire Nut") ](https://www.youtube.com/watch?v=katwxG_1cqM) Both wire nuts and Wagos are very good, and add only a fraction of a _milli_ohm each. He doesn’t test screw terminals, but I have to imagine that a properly installed one would have similar resistance. Even with 20 items in the chain (10 receptacles \* 2 terminals/receptable), the voltage drop should be negligible. ---
**Author:** ![Bob\_Blaylock](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_blaylock/32/3235_2.png) [@Bob\_Blaylock](https://boards.straightdope.com/u/Bob_Blaylock)\ **Post date:** [October 29, 2022, 12:58am UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/44 "2022-10-29T00:58:38Z")
> [@Dr.Strangelove](#): > > The longer the wire, the more resistance. Of course, if you’re a Borg, then it doesn’t matter. In that case, “Resistance is futile!” A similar principle applies if you’re a Vogon guard, in which case, “Resistance is useless!” ---
**Author:** ![Snipe70e](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@Snipe70e](https://boards.straightdope.com/u/Snipe70e)\ **Post date:** [October 29, 2022, 4:55am UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/45 "2022-10-29T04:55:16Z")
> [@md-2000](#): > > My thought is too high a resistance is a problem. 10V difference when pulling 10A across a end of a circuit chain seems like a decent amount of heat in the walls, especially if it’s one problem connection in the chain. That voltage drop was not all in one location but spread out over over 20 locations But it still was not good. > [@md-2000](#): > > A few years ago, I saw that commercial spaces around here had gone the route of mapping out and labelling receptacles (and lights) to breakers, presumably for workplace safety reasons. Not so much workplace safety, but to make the job easier. If the outlets, lights, and light switches are labeled makes problem solving easier. If a tenant overloads a circuit and trips the breaker, If the outlet is labeled then it is just a matter of going to the right electrical panel and locating and resetting the breaker. If it is unlabeled, then I would have to find which panel room the power came from and which panel. The is either checking the blue prints if there are any or walking in each panel room checking each panel and locating a tripped breaker. Resetting the breaker. Also If the outlets are labeled and an event is being set up with several high draw appliances, then it will be eassier to plug in the appliances and not over load the breaker. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [October 29, 2022, 12:20pm UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/46 "2022-10-29T12:20:07Z")
> [@Bob\_Blaylock](#): > > There’s a difference between a failure that results in something just not working, and a failure that can kill someone. That’s the difference between a failure in the hot connection, to downstream receptacles, and a failure in the ground or neutral connections. > > If the hot connection fails, then you just don’t have power. > > If the ground or neutral fail, then you have a significantly-increased risk of someone getting electrocuted. Any failure that results in something not working is a significant risk that it’s a failure that’s building up to an electrical fire. Most electrical house fires from what I read are due to _poor_ connections. You most certainly don’t want to nt notice or ignore an electrical problem. You don’t want to ignore a malfunction, and continuing to use a faulty circuit is probably not recommended. > [@Dr.Strangelove](#): > > Not so negligible that you can’t measure it. If the wire resistance ends up as 0.2 ohms, that’s a 3 volt drop @ 15 A, or 2.5%. > > I’m not sure what a receptacle adds. It’s surely higher with a backstab connection than screw-on. And higher yet as a bit of corrosion sets in. 6 volts for a circuit chain there and back that’s 100 feet long each way is not bad. (and technically, for a 15A circuit the typically max continuous draw should be 12A, 80%). If there is corrosion or a faulty connection, that’s all in one spot and that’s a risk of worse consequences. My house built in 1962, in the late 90’s I had to call an electrician because the main breaker kept popping more and more often until at least once a week. He found that the copper wire feeding from the street had deformed over the years so the connection was not tight going into the breaker. He could, with the power off of course, pull the wire in and out by hand. Tighten it down, no further problems. But the heat of the connection in heavy use would pop the breaker. It was a vicious cycle - heat from a poor connection caused the wire to expand and deform more, then when it cooled it was still looser. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [October 29, 2022, 10:09pm UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/47 "2022-10-29T22:09:55Z")
In the UK, we have traditionally had “ring final circuits” in which all the receptacles are connected in a loop that starts and finishes at the main circuit breaker. This is not the recommended method these days and “radial circuits” similar to those described above are the norm for new installations. I looked it up and see that the regulations say that _“If you adhere to the principles above e.g. a radial circuit running from a consumer unit with its own MCB of the correct rating can have as many sockets as you like, as long as it’s in an area not exceeding 50 square metres (or 540sq ft).”_ They do say that you should pay attention to what is likely to be plugged in. A 16 amp MCB with 2.5mm T+E (twin and earth) wiring will be ample for any general domestic appliances such as TVs computers, washing machines etc, but for heavy-duty appliances, such as cookers, a more substantial cable is required. The size of the wire and MCB breaker that’s used will very much depend on the rating of the appliance that’s going to be connected to it. Lighting circuits are usually made from 1mm T&E and a 5 or 6-amp breaker but may be 1.5mm on long runs or where ceiling fans are involved. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [October 29, 2022, 10:27pm UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/48 "2022-10-29T22:27:55Z")
> [@md-2000](#): > > 6 volts for a circuit chain there and back that’s 100 feet long each way is not bad. Sure, I’m not trying to imply that it’s a big problem. The wire gauge requirements are set so that the voltage drop is nominal. Any correctly functioning appliance can accept a 5% drop. It’s just not what I’d call negligible. Back when my lights were incandescent, I could always spot when a load came on the same circuit as some lights, as they’d dim slightly. Not significant, but still noticeable. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [October 30, 2022, 5:31am UTC](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850/49 "2022-10-30T05:31:33Z")
> [@Dr.Strangelove](#): > > Sure, I’m not trying to imply that it’s a big problem. The wire gauge requirements are set so that the voltage drop is nominal. Any correctly functioning appliance can accept a 5% drop. It’s just not what I’d call negligible. Back when my lights were incandescent, I could always spot when a load came on the same circuit as some lights, as they’d dim slightly. Not significant, but still noticeable. Yes, many appliances can’t make up their mind if they are nominally for 110V or 120V; there’s a certain latitude there. (Nowadays, many are 110-240V). I remember something similar, where things like my fridge’s compressor or the washing machine - when the motor kicked in the lights would blink. Lights were most apt to burn out with a big flash when you first turned them on. There would be a surge of current to start when the circuit first closed. I believe a lot of modern appliances have the electronics etc. to smooth out that surge. [Previous page](https://boards.straightdope.com/t/is-there-an-electrician-in-the-house-my-house-is-not-about-to-burn-down-or-anything/973850.md?page=2)