On Mon, 14 Sep 2015 20:06:41 +0100, John Rumm wrote:

On 14/09/2015 15:12, Tough Guy no. 1265 wrote:
On Mon, 14 Sep 2015 02:48:48 +0100, John Rumm
wrote:

On 13/09/2015 20:22, Tough Guy no. 1265 wrote:
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 let's say someone wanted to work on the switched live - adding an
additional lamp perhaps?

They'd have checked neither PIR was turning the thing on. Why would you
assume they were on the same circuit?

So if we apply that logic, before touching anything we need to check
every light switch, PIR, FCU and anything else with a switch on it, on
any circuit, just in case some clueless PHucker decided to wire it up to
the lamp as well.

Does your horse need feeding?

What a stupid train of thought. Both PIRs activate the outside light you're working on, so you check both. Why would you check the bedroom light switch when you know that doesn't activate it, and you know there's nobody else in the house to press it?

--
Rules are for the obedience of fools and the guidance of wise men.