On 17/11/2007, Mikkel L. Ellertson <mikkel@xxxxxxxxxxxxxxxx> wrote: > Frank Cox wrote: > > > > Electrical regulations vary substantially from place to place even within the > > same area. I have electrical inspectors (gas inspectors, fire inspectors, > > health inspectors, boiler inspectors, inspector inspectors I suppose) go > > through my theatre on a regular basis. One of those guys told me that it's > > illegal to use an extension cord in commercial building in some cities around > > here. Not in my city, though -- I had never heard of a restriction like that > > before. > > > For a lot of places, this is a fire regulation violation, and not an > electrical code violation. There are a couple of problems with using > extension cords. One of the biggest is that it is too easy to damage > one if you do not have it routed properly. Another problem is that > too many people use a cord that is too light for the job. Extension > cords come in different gages. There is often a chart showing what > gage cord is needed for what type of load, and what distance. And > you can really run into problems when you string then together. For > example, if you have 2 16 gage, 100' cords strung together, you can > short out the cord, and not trip a 20 amp breaker. The resistance of > the wire is enough to limit the current. It works well when you need > to free up a cord frozen in the snow. You can sometimes do it with a > pair of 50' cords as well. > > You also run into problems whey you start connecting motor loads. > Something like a small refrigerator or dehumidifier can cause real > problems. They may work fine under normal usage, but the first time > the power is interrupted when they are running, and then comes back > before the head pressure has bled off, you will have problem. The > motor can not get enough power to start under load, or to trip the > breaker, so it sits there, drawing the maximum power the cord will > provide, all the while the cord is acting as an electric heater > until it burns up, possible starting the building on fire. > > Also, the ban may not be on all extension cords. It may allow > appliance extension cords. These are normally 12 or 14 gage wire, > and are fairly short. This means they can carry enough current, and > are less likely to be subject to physical damage. > > Oh yes, cords are not allowed to be run through walls, ceilings or > floors. They are not allowed to be run in ceilings, nor where > subject to physical damage. This one reason that you see the metal > peace covering cords that have to cross a traffic area. (walkway) > The other is to prevent people from tripping on them. > +5 Informative Dotan Cohen http://what-is-what.com http://gibberish.co.il א-ב-ג-ד-ה-ו-ז-ח-ט-י-ך-כ-ל-ם-מ-ן-נ-ס-ע-ף-פ-ץ-צ-ק-ר-ש-ת A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing?
