On Sun, 06 Mar 2016 22:51:38 -0000, wrote:

On Sun, 06 Mar 2016 02:25:01 -0500, Micky
wrote:

On Sat, 05 Mar 2016 14:50:19 -0500, wrote:


Over here in the colonies we take that 240v and center tap the
transformer so both ungrounded legs are 120v above ground. That still
gives us the ability to use 240v equipment but most ends up being
120v. I suppose we can blame Thomas Edison for that. He started a fear
campaign against Nick Tesla over AC current, Edison wanted DC and he
said AC was more deadly, to the point of electrocuting an elephant
along with more than a few condemned prisoners ... all with AC.
When he lost the war, the deadly part still stuck and the belief was
that 120 would be safer, still leaving the option of having 240v
equipment.

I thought 240 was indeed more deadly than 120 and that more people
died of shocks, per capita, in the UK than here. How could 240 not
be more deadly than 120?
Something to do with the physiological responce to the shock. Some
voltages make you hang on, others throw you off - making it virtually
impossible to hold on.. I can't remember what my Dad used to say (he
was an electrician) but some of the higher voltages could be safer
than the lower voltages because the lower voltage made you grab the
wire hard and not let go.

I thought all AC allowed you to let go? DC cramps your muscles up.

The let-go phenomenon for low (600 V) contact

A factor that makes a large difference in the injury sustained in
low-voltage shocks is the inability to let go. The amount of current
in the arm that will cause the hand to involuntarily grip strongly is
referred to as the let-go current.7 If a person's fingers are wrapped
around a large cable or energized vacuum cleaner handle, for example,
most adults will be able to let go with a current of less than 6 mA.
At 22 mA, more than 99% of adults will not be able to let go. The pain
associated with the let-go current is so severe that young, motivated
volunteers could tolerate it for only a few seconds.

I call "********". I once picked up a wall socket which I'd used as a trailing socket, and it was wired backwards (earlier on, not by me), so when I'd switched it off, I'd disconnected the neutral and not the live. Hence I got 240V through my hand from live to earth. All it did was warm up my hand. I let go very easily.

7 With current
flow in the forearm, the muscles of flexion and extension are both
stimulated. However, the muscles of flexion are stronger, making the
person unable to voluntarily let go. Nearly all cases of inability to
let go involve alternating current. Alternating current repetitively
stimulates nerves and muscles, resulting in a tetanic (sustained)
contraction that lasts as long as the contact is continued. If this
leads to the subject tightening his or her grip on a conductor, the
result is continued electric current flow through the person and
lowered contact resistance.8

With alternating current, there is a feeling of electric shock as long
as contact is made. In contrast, with direct current, there is only a
feeling of shock when the circuit is made or broken.

Incorrect again. Place a PP3 9V battery on your tongue. That will sting continuously until you remove it.

--
I'd rather have a life than a living.