Two PIR sensors to actuate one device

[dennis]

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

[Tough Guy no. 1265]

No, it means you'd have one less conductor to bother wiring all over your house. And things that need RF shielding still get it. And if the live comes detached inside the machine and touches the chassis, it blows the fuse. The only problem that you're pointing out is you might get connected in series with the load, which is nothing like touching the live straight up.

Yes it does. I have done so. I just got a rather warm hand for a second.

Where the f*ck do you buy that shit from? I've never encountered such a thing.

[Tough Guy no. 1265]

e:

It is, see my post about the dangers being none to minimal.

I didn't lose the millions.

Dunno, medical science isn't a science yet.

-- =

Rescuers in Pakistan today reported rescuing a man from the rubble. They became aware when they heard a faint voice saying "we're still open= ".

[Tough Guy no. 1265]

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

[hqhy]

That assumes the PIRs produce power when not activated but powered.

False assumption with all of them.

[Tough Guy no. 1265]

I assumed no such thing. The relay of the sensor is open when sat in the box before you connect it up. It remains so unless it has power given to it on its own circuit, and detects movement. If you switch off one of your two circuits, this means one of the PIRs cannot connect live to the lamp, so there is no way for backfeeding to occur.

[Jim Thomas]

But don't have the safety feature of an earthed body that protects against an active coming loose and connecting to the body, or the device failing in way that connects the active to the body. It isn't economic to double insulate everything, it makes more sense to have an earth for the stuff that isn't double insulated.

Not when you have backed off from your original stupid approach of connecting the neutral to the body.

And you can't rely on the fuse to blow in a fault condition that will still provide enough current to kill you.

But can still be enough to kill you or see you fall off the ladder and break something important etc.

No it does not.

And others have died that way.

Its quite common in europe.

And quite common in Britain for people to wire plugs incorrectly, swapping the neutral and active.

[Jim Thomas]

See the two posts pointing out your error there.

It was your ear to ear dog shit that produced the revealing.

Its plenty science enough to establish that.

[Jim Thomas]

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.

[Tough Guy no. 1265]

The neutral would protect this just as well.

I hereby un-back off. Metal chassis which aren't well insulated form live should be joined to nuetral.

Bollocks. If it won't blow the fuse, it isn't enough to even hurt you badly.

You're such a pessimist. These things are very unlikely.

Did with me. That's one of the reasons why we have AC, and why DC on trains is more dangerous.

Survival of the fittest.

That's their problem.

[Tough Guy no. 1265]

e:

ote:

Nobody has provided evidence of this. If you think you can, draw a circ= uit diagram.

The truth is always best.

Nope. They don't know what my illness is.

-- =

Two cowboys are talking over a beer, discussing various sex positions. The first cowboy says his favorite position is "the rodeo". The other cowboy asks what the position is, and how to do it. The first= cowboy says, "You tell your wife to get on the bed on all fours and the= n do it doggy style. Once things start to get under way and she's reall= y enjoying it, lean forward, grab her by her hair and whisper in her ear= , 'Your sister likes this position too.' Then try to hang on for 8 seco= nds".

[Tough Guy no. 1265]

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

[hqhy]

There is more than just the PIRs involved, there is also the manual override switch(es)

And the PIRs can be connected in parallel rather than in series too.

[Tough Guy no. 1265]

Why on earth would you switch on one of those to deliberately electrocute yourself?

Of course they're connected in parallel. That's what I have assumed in the above.

[Jim Thomas]

Not if it comes off at the same time the active does, which is very likely when the end of the cord in the device comes free.

Which will kill you with an active neutral swap in the power point or extension lead or a badly fitted plug.

That is the reason the regs don't allow that.

That is just plain wrong. A lot more current is required to blow the fuse than will kill you.

Same with anything that can kill you.

Killed others.

The reason for that is because that allows transformers which reduce current losses in the distribution system.

You're actually the least fit, completely unemployable.

It's the reason the regs don't have the neutral connected to the body and no earth.

[Jim Thomas]

Don't need any circuit diagram with PIRs in parallel and manual override switch(es)

It clearly wasn't for you.

They do actually, ear to ear dog shit.

[Jim Thomas]

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

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.

[Tough Guy no. 1265]

In which case an earth would do the same.

Why protect the very very very few that stupidly wire things backwards? There's a reason the wires are colour coded.

If it can't blow the fuse, there is some resistance somewhere, which means you will be in series with that resistance, and not get the full voltage.

So stop worrying. You're beginning to sound like a Brit. Where are your Aussie balls?

Survival of the fittest.

That is another reason.

I am self employed. I do not have an alarm clock.

[Tough Guy no. 1265]

e:

ote:

You do, you need to prove to me that you are right. Go on, then you can= gloat forever.

Their loss. I know what happened after I left.

If it was that it could be sucked out.

-- =

Many of the world's greatest runners come from Kenya because they have a= unique training program there -- it's called a lion.

[Tough Guy no. 1265]

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.