OT: Computer's electrical outlet
dotancohen at gmail.com
Sat Nov 17 22:20:58 UTC 2007
On 17/11/2007, Mikkel L. Ellertson <mikkel at infinity-ltd.com> 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.
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
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