"Tough Guy no. 1265" wrote in message
news
On Mon, 14 Sep 2015 20:34:22 +0100, Jim Thomas wrote:



"Tough Guy no. 1265" wrote in message
news
On Sun, 13 Sep 2015 22:12:25 +0100, Jim Thomas wrote:



"Tough Guy no. 1265" wrote in message
news On Sun, 13 Sep 2015 21:37:17 +0100, Jim Thomas wrote:



"Tough Guy no. 1265" wrote in message
news On Sun, 13 Sep 2015 20:50:55 +0100, Jim Thomas
wrote:



"Tough Guy no. 1265" wrote in message
news On Sun, 13 Sep 2015 20:19:43 +0100, dennis@home

wrote:

On 13/09/2015 20:11, Tough Guy no. 1265 wrote:

I'm right, if you think I'm not, prove it. A sensor needs power
to
activate the relay. It cannot have this until its source
circuit
is
made live, and you switched that off. All the other sensor can
do
is
connect live to the output of the relay contact of the first
sensor.
This will not power up the first sensor so its relay remains
open.


If you ignore the circuit to the lights and any manual override
switch.

Only the light in question could become live, nothing else.

And that can be the one you are rewiring that can kill you or see
you
fall of the ladder from the shock and break something important.

If you're rewiring the light, you make sure both PIRs are inactive
DOH!

Not even possible without turning off the power to the entire house.

Why would anyone assume that they are both on the same circuit? You
switch off a breaker, then walk in front of each PIR and see what
happens.

Useless when the breaker turns off the power to the light, but not
one of the PIRs which has no indication that its been triggered.

Like I just said, you switch off the breaker, then walk in front of
both
PIRs. If the light does not come on, you have no power available, and
it's safe to work on the light.

Not when the cat triggers the PIR that has not been turned off.

What part of "walk in front of both PIRs" didn't you understand?

What part of "PIRs which has no indication that its been triggered"
didn't
you understand?

The wires you're working on would become live, and your meter would
indicate this.

But you can't see the meter when you walk in front of both PIRs.