Posted by lousahr (My Page) on Sun, Apr 17, 05 at 12:22
Hi, I could use some help on figuring out the best way to wire this scenario. I want the outlet to always be on as well.
- I have 2-wire power coming into the light switch. This is my power source. - I want the switch to control wall light right above the switch. - I have installed 2-wire cable to fixture. - There is 3-wire cable leaving the light switch and going to an outlet below the switch. - The outlet below also has 2-wire cable going to another outlet down stream
Can someone please tell me which cables should be connected to with screws?
Re: DIY Elect Wiring Forum#50986 04/18/0507:29 AM04/18/0507:29 AM
how dangerous is #14 wire on a 20amp breaker Posted by Consed (My Page) on Mon, Feb 28, 05 at 14:15
A long time ago, we had a guy who had 20amp breaker on a circuit wired with #14 wire. We all gave him a very hard time, but he argued back, saying things such as "I know what anyone in this house plugs into that circuit". Some of us told him his house would burn down and the insurance company wouldn't pay. I personally have been uncomfortable with #14 wire (even on lighting circuits, since given enough years, lighting circuits generally turn into general purpose circuits) and thus I have replaced just about all my #14 with #12.
But so far we have argued about the danger of #14 based more on religion than fact. I asked for someone to test #14 with over 15amps, but no one responded that they had done so.
Finally, I decided I would do the test. I did so this weekend and I think I have fairly definitive results.
Here was my experimental setup: 20amp breaker to receptacle to #12 extension cord to short piece of #14 (type NM) Romex to short piece of #12 (type NMB) Romex to triple tap extension cord to hair dryer and vacuum cleaner. Next to this setup was another piece of #14 Romex not connected to anything. I used a Fluke clamp-on ammeter to measure the current. I cranked up the hair dryer and the vacuum cleaner until I had 19 amps going through everything (except for the little piece of unconnected #14). I let this run for 30 minutes and felt the temperature of each of the wires. And here is what I found:
#14 unconnected--very cold (as all wire was before starting) #12 with 19 amps--warm #14 with 19 amps--the warmest, but not uncomfortably warm. You could keep your hand there indefinitely. It certainly was not warm enough to start a fire with either paper or even gasoline.
My conclusion: (Here is where I'm really sticking my neck out, so I hope I don't get beat up too badly) #14 wire on a 20amp breaker is not unsafe.
Arguing against myself: I did the test for 30 minutes. How about if the 19amps had run for 10 hours (20 times as long)? Would the #14 have heated up enough to start a fire then? How about if it was also buried insulation? Maybe...but it is time for someone else to do the next test.
(To Pittsburgh: I guess you are right.)
I welcome all comments (and jokes).
Re: DIY Elect Wiring Forum#50987 04/18/0508:56 AM04/18/0508:56 AM
One can argue forever on things like this- but why re-invent the wheel? Fact is, there's more to wiring than just the wire. Connections are also an issue. And the argument "I know what's going to be used" doesnt explain the opposition to having too large a breaker on the load. Would you protect a 3 amp motor with a 100 amp breaker?
Probably the most common "weak link" in a #14 circuit are receptacles with the 'push-in' connections; some of these only have the push-ins, and no attachement screws. Even with a little experience, you get to see these 15-amp rated devices fail with simple age and light use. Would you want to aggravate the situation by running 20 amps through them?
All code decisions are essentially commonly accepted judgement calls....that is, there were enough problems to justify a stronger rule. We had the discussion, this was the decision. Even when you might think the code is being silly- there are several instances that come to my mind- you have a duty to follow it.
Re: DIY Elect Wiring Forum#50989 04/18/0510:31 AM04/18/0510:31 AM
I tested a 20-amp circuit under load recently. It drew 16 amps, and climbed to 24-amps. This was a high quality breaker(QO), not tripping at 24-amps, so the 19-amp test isn't quite right. Also, as Doug implies, let's try four such loaded circuits in 50' of EMT wrapped in insulation. I'll bet the conductor insulation fails in time.
More and more electricians are avoiding residential work, especially minor repair jobs. There's too little money in it, and too many costs (fuel, insurance, etc). Then newer codes restrict what kinds of work can be done (for example not extending a 2-wire or undersized circuit for an additional outlet), putting much work out of the price range of many customers. To me there is no surprise that more and more people are doing the work in their homes themselves. And in many cases they are even doing it elsewhere (rental property, offices).
So what's the best solution?
Sure, it would be great for electricians if the customers would just pay what the work is really worth (and the other costs to do the job), and be happy with the quantity of work that's needed to make sure everything that gets touched is fully up to today's code. Unfortunately, everyone (who matters) is being squeezed right now in an economy geared to grow only for the rich.
I think there's simply going to be a certain amount of DIY work going on. The question is whether you want to spend your time and give out free advice at the risk that maybe someone won't call an electrician to do the work, or worse, might make a mistake (observed wrong, described the situation poorly, or misunderstood the advise) and get someone hurt or killed.
I have given out advice in that and other forums. But I'm not an electrician (instead, I do design work for computer data centers which sometimes requires electrical specifications), so my advice can't be the best. I think real experienced electricians giving advice would help. But you have to decide if doing so means another electrician has to miss a meal. I've certainly given out lots of free computer networking advice in other places, and felt a bit uneasy about it because they should just hire someone who knows how to do it right to do it for them. I'm sure it's the same way with electrical work, and even more importantly because this stuff can kill (unlike TCP/IP packets).
I have already come across a light fixture wired with telephone wire back in the early 1980's. Here in the Mountain State, if it can conduct electricity, someone will use it. I've found shooting wire from the mines, zip cord, twin lead antenna wire, plastic covered aluminum clothes line all being used as conductors.
As for DIYers. They will keep on doing their own work. Its your choice, laugh at them or try to help out & keep them from getting hurt. After all, they are risking more than their own lives, there are fireman & EMT's to think of too.
Few things are harder to put up with than the annoyance of a good example.