On Tue, 05 Sep 2006 20:55:05 -0000, (Chris
Lewis) wrote:

According to Pat :
That _hurt_. Even without ringing. Was unable to grasp/twist
the wire.

Huh. I always work on phones barehanded and never had a problem.

So do I. But have you ever done it whilst in shorts sitting on
bare concrete?

Trying to remember if I've ever worked on them barefoot, too, but can't
think of any time I did that. Never had a problem. Bared wires with a
jacknife, pulled off cut insulation with my teeth, etc.

Ordinary shoes/carpet make a _big_ difference.

What's the consensus. Do most people feel the voltage out of a phone
or not?

Generally speaking, if you're reasonably grounded (bare legs on
concrete ;-), most people start feeling things at around 35-40V.

BTW, my father (an electrician) always said that ringer voltage was
esp. dangerous because it was close to the voltage of your heart. I
don't have any idea if that is true or just an old wives tale.

I assure you, your heart doesn't run at 90V.

Ringer voltage is perhaps somewhat more, um, "memorable" for
two reasons. One is that it's closer to DC, which is inherently
somewhat nastier than the same voltage in AC. The second, more
important one, is that you're firmly grasping it thinking all is
right with the world, and _zap_ out of nowhere, you get hit.

Since your muscles are already gripping it, the ringer voltage
tends to keep you gripping it even harder. Longer duration
contact. Maybe a whole ring cycle before you can let go.

In contrast, you don't usually have anywhere near as good a
connection to line voltage when things start to hurt, and short
of a "fall into" or a misguided "firm grab", the muscular reaction
tends to knock your hand or finger _away_. Grab that switched
off switch leg firmly, and have someone flip the switch on. That's
very much different, and vastly more likely to be lethal than
a mere "graze".
--

The on-hook voltage is DC and is going to be around 40-50 volts and
the current is near zero. You can feel this under certain
circumstances. The voltage drops dramatically when the phone goes off
the hook to perhaps 9 volts or so. Standing on a ground is not
usually a problem around telephone wires unless you are in an
electrical storm. The loop (off hook) current is limited by a
resistor at the phone exchange to about 20 ma or so, even if the wires
are shorted together.

Long lines in rural areas might have higher loop current, but again,
phone wiring is not considered dangerous except with the thunderstorm
exception.

Ring voltage is going to be higher, anywhere from 90 volts AC or
higher, but normally not with enough current to kill you unless you
are at the top of a telephone poll and the shock you receive causes
you to fall off and break your neck.

Remember, transformers only pass AC and block DC. (Telephone audio
signals are considered AC even though they are really varying DC. - A
transformer is said to pass the AC component of the DC as long as it
is not overdriven or saturated).

Capacitors block DC and pass AC.

Beachcomber