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.

--
Why is there no Disneyland China?
No one's tall enough to go on the good rides.