# I pit the National Electrical Code **URL:** \ **Category:** The BBQ Pit\ **Created:** [November 20, 2012, 1:28am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569 "2012-11-20T01:28:33Z")\ **Posts on this page:** 19\ **Page:** 1
**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:** [November 20, 2012, 1:28am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/1 "2012-11-20T01:28:33Z")
I was going to pit lazy electricians, but it turns out that the problem is actually with the NEC. A friend was recently installing an electronic timer switch. It kinda worked–except when another switch in the box was flipped (!). Okay, I fully grant that this friend should probably have just hired an electrician. But in any case I get a call since I’m a pretty good diagnostician. I ask them to send me a picture of the setup. Looks good so far… all the colors are hooked up to the right place. But what’s happening with that white wire? I can’t make it out too easily, but it very much looks like the other end is going into a three-way switch (along with two blacks). Uh-oh. Yeah, so they had tapped into a hot traveler wire and connected it to the neutral on the electronic timer. I’m \*shocked \*that the timer had enough protection not to explode or start a fire or something, but fortunately it did. Anyway, apparently the NEC actually allows traveler wires to be white instead of the typical red. Of course, there was no tape or note or marking or anything to indicate that this was actually a hot wire. And yeah, a trained eye would have instantly noticed that the only reason for a mechanical switch to have a white wire going in is if it’s the traveler wire for a 3-way switch, but still–this is pretty damn confusing and very dangerous. Millions of homeowners are out there doing their own electric work with a basis of just getting the colors right. So fuck you, NEC. And the lazy electrician that thought just abiding by the letter of the code was good enough. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 20, 2012, 2:07am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/2 "2012-11-20T02:07:40Z")
Just getting the colors right isn’t the basis. I’ve never heard anyone say it is. Doesn’t everyone test to make sure? ---
**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:** [November 20, 2012, 2:21am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/3 "2012-11-20T02:21:01Z")
> [@TriPolar](#): > > Just getting the colors right isn’t the basis. I’ve never heard anyone say it is. Doesn’t everyone test to make sure? It’s not a \*good \*basis. And no, not everyone tests to be sure. I’d bet that 90% don’t even own the correct test equipment. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 20, 2012, 2:36am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/4 "2012-11-20T02:36:39Z")
Well there’s a lot of pitting to go around then. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [November 20, 2012, 2:44am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/5 "2012-11-20T02:44:02Z")
I just rewired my entire basement, all to code, all to safety standards. The biggest nuisance was having to get new breakers - I’d accumulated a few over the years and came to realize that using a 40-amp breaker on a circuit with a 12-gauge wire was probably a bad idea. ---
**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:** [November 20, 2012, 2:45am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/6 "2012-11-20T02:45:04Z")
> [@TriPolar](#): > > Well there’s a lot of pitting to go around then. Indeed. But the NEC should know better. It is very dangerous to have a rule (white means neutral) that, occasionally, has an extremely dangerous exception (white means neutral, except when it’s not, and then it is a hot traveler wire). Having a dangerous thing have a safe exception is ok. The reverse is not. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 20, 2012, 2:49am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/7 "2012-11-20T02:49:33Z")
> [@Dr.Strangelove](#): > > Having a dangerous thing have a safe exception is ok. The reverse is not. Agreed. ---
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [November 20, 2012, 4:00am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/8 "2012-11-20T04:00:45Z")
> [@Bryan\_Ekers](#): > > I just rewired my entire basement, all to code, all to safety standards. The biggest nuisance was having to get new breakers - I’d accumulated a few over the years and came to realize that using a 40-amp breaker on a circuit with a 12-gauge wire was probably a bad idea. Did your walls start to glow? :eek: Had a friend who realized he’d either have to rewire his den or put some of his stuff on another circuit when his wall got warm. He might have also used a penny as a fuse, but what did he know? He’s just an EE. ---
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [November 20, 2012, 4:09am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/9 "2012-11-20T04:09:30Z")
ETA, but too late: Had a duplex outlet with the receptacles on different circuits. Big surprise when I only switched off one and tried to replace the outlet. By feel. In the dark, except when my screwdriver shorted it out for a second. Hey, I was in too big a hurry to turn off the other circuit, 'kay? And I didn’t even die once. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [November 20, 2012, 3:02pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/10 "2012-11-20T15:02:13Z")
if the white wire is not a neutral it needs to be relabeled, then it is good. that needs to be done correctly. timers need a neutral to work. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [November 20, 2012, 9:34pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/11 "2012-11-20T21:34:55Z")
> [@Bryan\_Ekers](#): > > I just rewired my entire basement, all to code, all to safety standards. The biggest nuisance was having to get new breakers - I’d accumulated a few over the years and came to realize that using a 40-amp breaker on a circuit with a 12-gauge wire was probably a bad idea. One might note that 12 gauge wire can actually handle WAY more than 40 amps\*; [this table](http://www.powerstream.com/Wire_Size.htm) says 41 amps (and that is conservative), although that is for chassis wiring (for power transmission, 12 gauge is shown to be only 9.3 amps, half of what it is used for in home wiring). \*For kicks, [this MOSFET](http://www.futurlec.com/Transistors/IRF3205.shtml) is rated at 75 amps (“limited by package”, in small text at the bottom of page 2, they often do this for such high-current MOSFETs) but the leads are about the thickness of 22 gauge (!) hookup wire (7 amps according to the table, or 0.72 for transmission), although less than an inch long. I also recently used 28 gauge ribbon cable wire at 5 amps (table say 1.4 amps for chassis wiring and 0.226 amps for transmission) for temporary connections (no, not house wiring, I was testing a power supply I made and used the wire to connect a load resistor to it) and it only got warm, not too hot to touch (rated at 105C). ---
**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:** [November 20, 2012, 9:58pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/12 "2012-11-20T21:58:37Z")
> [@johnpost](#): > > if the white wire is not a neutral it needs to be relabeled, then it is good. that needs to be done correctly. Like I said, there was no labeling of any kind. > [@johnpost](#): > > timers need a neutral to work. Not always. Obviously, clockwork mechanical timers will work with no neutral. And battery-powered electronic timers will work. However, this one was line powered and certainly needed the neutral. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [November 20, 2012, 10:15pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/13 "2012-11-20T22:15:57Z")
> [@Michael63129](#): > > One might note that 12 gauge wire can actually handle WAY more than 40 amps\*; [this table](http://www.powerstream.com/Wire_Size.htm) says 41 amps (and that is conservative), although that is for chassis wiring (for power transmission, 12 gauge is shown to be only 9.3 amps, half of what it is used for in home wiring). Yeah, but I’d already had a problem with a 30-amp outlet for a 4800 watt heater partially melting because the wire feeding it was 12 gauge. It’s since been rewired with 10 gauge. ---
**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:** [November 20, 2012, 10:19pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/14 "2012-11-20T22:19:04Z")
> [@Michael63129](#): > > but the leads are about the thickness of 22 gauge (!) hookup wire (7 amps according to the table, or 0.72 for transmission), although less than an inch long. What’s really astonishing is that if you dissolve the package and look inside, the wires connecting the external pins to the semiconductor are like fine hairs; 30 gauge or above wouldn’t surprise me. They survive because they’re short, in good electrical contact with some larger chunks of metal, and because the package itself removes some of the heat. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [November 20, 2012, 10:37pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/15 "2012-11-20T22:37:06Z")
> [@Dr.Strangelove](#): > > So fuck you, NEC. And the lazy electrician that thought just abiding by the letter of the code was good enough. I’m like 93% sure that the NEC requires hot whites to be marked with a piece of black tape or a stripe. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [November 20, 2012, 11:14pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/16 "2012-11-20T23:14:49Z")
> [@Bryan\_Ekers](#): > > Yeah, but I’d already had a problem with a 30-amp outlet for a 4800 watt heater partially melting because the wire feeding it was 12 gauge. It’s since been rewired with 10 gauge. I always hear this, but it makes me wonder if it is due to bad connections rather than the size of the wire itself, since after all, it isn’t very practical to solder wires to an outlet, which can make a much better connection. Although at 30 amps I calculate a power loss of 1.43 watts per foot of 12 gauge wire using the resistance in the table I previously linked to, which will make it noticeably warm (but not excessively hot), especially when two wires are run together (10 gauge dissipates 0.9 watts per foot, or 0.64 and 0.4 watts respectively at 20 amps, assuming it is a 240 volt heater); 12 gauge is the correct gauge for 20 amps although code requires heavier wire for a 30 amp breaker, but in this example 12 gauge running at 20 amps (0.64 W/ft) would be cooler than 10 gauge at 30 amps (0.9 W/ft). > [@Dr.Strangelove](#): > > What’s really astonishing is that if you dissolve the package and look inside, the wires connecting the external pins to the semiconductor are like fine hairs; 30 gauge or above wouldn’t surprise me. They survive because they’re short, in good electrical contact with some larger chunks of metal, and because the package itself removes some of the heat. Yeah, that explains why the failure of a transistor in a power supply can often be explosive, due to the internal wires vaporizing (you can often even see channels burnt into the epoxy). ---
**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:** [November 20, 2012, 11:26pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/17 "2012-11-20T23:26:35Z")
> [@friedo](#): > > I’m like 93% sure that the NEC requires hot whites to be marked with a piece of black tape or a stripe. Hell, it looks like you’re right. NFPA 70, 2001, Chapter 2, part 200.7 (C): _(C) Circuits of 50 Volts or More. The use of insulation that is white or gray or that has three continuous white stripes for other than a grounded conductor for circuits of 50 volts or more shall be permitted only as in (1) through (3). (ROP 5-31) … (2) Where a cable assembly contains an insulated conductor for single-pole, 3-way, or 4-way switch loops, and the conductor with white or gray insulation or a marking of three continuous white stripes is used for the supply to the switch, but not as a return conductor from the switch to the switched outlet. **In these applications, the conductor with white or gray insulation or with three continuous white stripes shall be permanently re-identified to indicate its use by painting or other effective means at its terminations and at each location where the conductor is visible and accessible**. (ROP 5-31, 5- 46)_ So my original intuition about the lazy electrician was correct–the traveler wire should have been permanently marked (and I think the house is in fact newer than 2001). Sorry for doubting you, NEC. ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [November 20, 2012, 11:30pm UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/18 "2012-11-20T23:30:03Z")
> [@](#): > > I pit the National Electrical Code But, without it, how will electricians send one another vital secret messages? ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [November 21, 2012, 2:18am UTC](https://boards.straightdope.com/t/i-pit-the-national-electrical-code/641569/19 "2012-11-21T02:18:39Z")
> [@Dr.Strangelove](#): > > So my original intuition about the lazy electrician was correct–the traveler wire should have been permanently marked (and I think the house is in fact newer than 2001). Sorry for doubting you, NEC. That’s OK. According to the latest edition you are forgiven.