On Wed, 16 Mar 2016 22:39:44 -0000, "Mr Macaw" wrote:

On Mon, 14 Mar 2016 04:22:42 -0000, wrote:

On Sun, 13 Mar 2016 18:41:50 -0000, "Mr Macaw" wrote:

The problem is when there is more than one circuit in the box or when
people assume all white wires (neutral here) will be grounded. If you
open up that wire nut only one of those wires with be ground, the
others may be at full line voltage through the connected load.

Firstly, why on earth would you have more than one lighting circuit? Secondly, if you do, simply use a multimeter!

They tend to use the large ceiling boxes as junction boxes and there
may be a number of circuits radiating from there. We don't have loops.

How weird. My electricity travels to each lightswitch in turn, then IF the switch is on, then there is electricity at the light. Why send the electricity to the light, down to the switch, then back up to the light?
Our wiring is radial, not a loop. They have a code change now that
will make these 2 wire switch loops (down to the switch) less popular
but there are millions of houses with them.
Now they must bring the neutral to all switch locations so feeding it
from the line neutral pair is desirable.


The other problem is, as long as all the neutral wires are connected,
it will be near or close to 0 volts. It is when you open that circuit
that you see line voltages through connected loads.

Which is harmless as a load has resistance.

What is the resistance of the load (100ohms?) and what is the
resistance of your body (100,000 ohms). Mr Ohm says .12v will be
dropped across the load and 119.88v will be dropped across your body.