This seems to be heading off topic a bit. In an effort to kill this branch:
It takes about 40 volts or more to overcome the skin surface resistance. That’s why cars and battery systems in general are limited to 12 to 24 volts. However, if you (God Forbid) short across the battery terminals with a conductor like a wire, you will quickly find out how much power is in 500 amps. It’s not a pretty sight.
The only reason voltages less than 500 volts could possibly be considered more deadly than higher voltages is that it it much harder to expose yourself to high voltage systems with real amperage capacity. Ask any electrician if he’d rather tangle with a 110 volt circuit or a 13,600 volt primary on a transformer.
Electric fences do indeed have thousands of volts. The general range is 2000 to 10,000 volts. Many places legally limit the voltage to 10,000 and less than 2000 is not effective in shocking animals with thick skins and heavy coats. To make the fence effective in dry weather, at least 5000 volts is preferred. Having grabbed a few fences, I can verify they are thousands of volts while you are touching them. Extremely low amperage though.
Learning from past experience when we built our last house the outlets behind the washer and dryer are at the height of those appliances. Also I put outlets ( and cable connection) at the height of the tv shelf in the bedrooms.
It is impossible to design a power supply that can independently source a given voltage and a given current into an arbitrary load[sup]a[/sup]. In other words, if someone said, “I have an electric fence that sources 5000V at 1 mA,” and they believe you will be subjected to 5000 V and 1 mA if you touch it, it would be an immediate tip-off that they don’t know anything about Ohm’s Law, source resistance, and voltage dividers.
As an example, let’s assume the electric fence uses a linear supply with a brick wall current limit. If it is rated for 5000 V and 1 mA, it means the following:
a) If the load resistance is greater than 5000000 Ohms, 5000 V will appear across the load and less than 1 mA will flow through the load.
b) If the load resistance is exactly 5000000 Ohms, 5000 V will appear across the load and 1 mA will flow through the load.
c) If the load resistance is less than 5000000 Ohms, less than 5000 V will appear across the load and 1 mA will flow through the load.
Your body is probably less than 5000000 Ohms, so c) would apply when you are touching the fence.
[sup]a[/sup] [sub]Except at exactly one load impedance.[/sub]
I’m not sure why the fencer power source would be looked at as a power supply since it actually is a capacitor discharge. It has a certain stored energy with an initial potential value of, say 5000 volts. When you touch it, you will, for the first microsecond have a 5000 v potential and current will flow with relative large current, as calculated by Ohms Law. However, as soon as that happens, the energy discharges, the potential drops drastically and the current drops quickly until the capacitor is discharged. It seems to me you see high voltage the same as you see high voltage off the ignition coil of a car.
I didn’t know electric fences worked by discharging a capacitor into the load. (Learn something new every day.) If this is the way it works, then you’re correct - the instantaneous current would be proportional to the instantaneous voltage, which would be exponentially decreasing over time.
Generally, the ADA (disabilities act) requires an outlet in a residence to be at least 14 inches to center off the ground. Oultets between (14 inches) and (5 feet 6 inches) off the floor are considered to be in the realm of legal spacing per NEC.
((Chefguy, yes we use our hammer as the spacer between the floor and the bottom of the box. The hammer is 14 inches long, which puts the box at about 16 inches to center.))
I believe the height restriction for a switch is 42 inches per ADA.
It`s been a while since I roughed a house.
The horizontal spacing of the outlets is also spelled out in the code book.
“It’s not the voltage that kills you, it’s the amperage”
It’s the voltage AND the amperage
v = ir
i = v/r
r = v/i
See a pattern? they are all interconnected. Touch a line with eleventy billion volts and 0 amps and you will be fine. Touch a line with eleventy billion amps and 0 volts and you will be fine.
As to the OP, outlets don’t have to be anywhere. They are placed where they are placed as a matter of convenience, convention and practicality. Most of the electricians that wire houses are working on houses for other people. To make assumptions as to where those people intend to put their furniture and appliances in the middle of a living room is ridiculous. Instead, they place the outlets towards the floor at regular intervals, to accomodate the widest possible variation of configurations.
Sure, outlets 4’ off the floor would be fine in your baby proof house where your nine month old can crawl right underneath them, but for those of us who are older than nine months, cords and outlets at waist level are a bit impractical.
The OP is going off a flawed premise. It’s not even true and we are rationalizing why it is so.
Fact is, electricians will place outlets with obvious uses at more convenient heights: kitchen counter height…outlet near wall phone jack for cordless phones…outlets high as washer/dryer…higher up on wall behind fridge…outlets in some cabinets…or right under all window sills, horizontal mounting hidden for ‘holiday lights’ and all wired to the same switch…higher on walls in garages for tools…on ceilings for garage door openers…in floor for vacuum cleaners…bathrrom counter height.
Upon counting, more than half of all available outlets in my home are not 14 inches off the floor, but in various vertical locations.
Ahhh-Haahhh! In the kitchen scene of the movie Kill Bill, there’s an outlet above the top of a door frame that kept distracting me, making me think “What in h*** is an outlet doing all the way up there?” Wall clock, huh? Answers one of my more perplexing riddles of the last few weeks. I’ve got a clock on my stove, on my coffee maker, and on my microwave, I never thought of putting one on the wall, too!
A few years ago I built (along with the help of carpenter friends) a very small studio house (about 400 sq. ft.). It was basically a big room with a bathroom. I put all the outlets at about 4.5 feet. Having used it for a few years now, I really like the outlet positions that high. The only drawback is the aesthetics, but my stuff in there (bookcases, etc.) covers most of the outlets so it works out great.
depends on what the voltage appears across, if you grab two terminals with your both hands you are in deep trouble cuz the current will go through your heart
i have been hit with 220v ( europe ) when i was a kid, but it wasn’t very bad cuz i was apparently only holding it with one hand. i felt my arm twitch up to about shoulder but no farther ( i was fixing up christmas tree lighting ).