Can't put PIR sensor into manual override

[mrshr]

I'm still concerned about how I've wired it. Shouldn't there be a permanent live to the pir?

No, you need the switch to enable the pulse mode over-ride.

I can see how the switch would provide the pulse, but wouldn't the PIR also need a permanant live connected when the pulse is applied?

I'm just thinking along the lines of an extractor fan. That has a permanant live and a switched lived to trigger the overrun timer.

To me, it should be similar for the PIR setup. Wouldn't you agree?

 

[mrshr]

However, you could rewire it so that there is a permanent live and the switched live is connected to L1 on the PIR.

I see what you mean. I guess this is how you'd wire up a PIR that doesn't have the in built override facility.

So if you feel that I've wired it correctly then it must be a faulty PIR.
Based on that, I'll take it back and get it swapped. I just didn't want to return it if, in fact, I was the problem rather than the sensor!!

 

[bernardgreen]

The over ride function can be better achieved using a PIR without over ride and two switches.

PIR with overrides

• bernardgreen
• 18 Mar 2011
• 20

Using two single pole switches to provide overrides for a basic PIR

A bit more expensive but the advantage is that even if the PIR fails there is still full control of the lamp.

 

[EFLImpudence]

, but wouldn't the PIR also need a permanant live connected when the pulse is applied?

No.

 

[mrshr]

, but wouldn't the PIR also need a permanant live connected when the pulse is applied?

No.

Sorry to go on about this, but really?

I'm thinking of rewiring as follows:

Earth to Earth
Neutral to Neutral
Loop from rose to L on PIR (i.e. parmanent live)
L1 from PIR through switch to lamp load.

In my mind there has to be a live permanently going to the PIR so that the onboard electronics within the PIR can see the pulse from the switch.

The way I have it wired means the PIR only sees the live with the switch on.
So doing the sequence of OFF/ON OFF/ON, the PIR is momentarily isolated during that short period of when the switch is OFF.

My problem is that I'm still thinking along the lines of an extractor fan with run on timer.
Are you saying that I'm wrong to be thinking along these line?

 

[Aragorn84]

yes your wrong.

The PIR presumably has some circuitry inside (such as a capacitor) which stores up some charge, and uses this to detect the off/on cycle.

I'd imagine that when it transitions from off to on, it simply checks to see if the capacitor still has charge in it. If it does it assumes you want override and latches on.

 

[mrshr]

D'OH!!

Just had a re-think:

The instructions say that to put it into manual mode you either:

flick swich off/on off on within 2 seconds,

or if you don't have a switch installed then flick the mcb off/on off/on within 2 secs.

So flicking the mcb off would defo remove the live, therefore a permenant live is NOT required, as you said.

Sorry for questioning you mate.

 

[mrshr]

yes your wrong.

The PIR presumably has some circuitry inside (such as a capacitor) which stores up some charge, and uses this to detect the off/on cycle.

I'd imagine that when it transitions from off to on, it simply checks to see if the capacitor still has charge in it. If it does it assumes you want override and latches on.

Yes I see what you mean. That does make sense.

So it's faulty. I'll get it changed.

 

[EFLImpudence]

, but wouldn't the PIR also need a permanant live connected when the pulse is applied?

No.

Sorry to go on about this, but really?

Yes, honest.

I'm thinking of rewiring as follows:

Earth to Earth
Neutral to Neutral
Loop from rose to L on PIR (i.e. parmanent live)
L1 from PIR through switch to lamp load.

You should not do that because it will be live permanently
with no means of isolation in the event of a fault.

In my mind there has to be a live permanently going to the PIR so that the onboard electronics within the PIR can see the pulse from the switch.

Presumably when the electronics 'see' two pulses, it doesn't turn off after the next one.
It can have a capacitor.

The way I have it wired means the PIR only sees the live with the switch on.
So doing the sequence of OFF/ON OFF/ON, the PIR is momentarily isolated during that short period of when the switch is OFF.

That's how they work.

My problem is that I'm still thinking along the lines of an extractor fan with run on timer.
Are you saying that I'm wrong to be thinking along these line?

You are wrong.

The permanent live is there because the switch is left on (you are leaving the switch on, aren't you) - unlike the fan.

You have wired it correctly.
If it doesn't work then it must be faulty.


How many hours are wasted by presuming brand new things must be ok?

 

[Taylortwocities]

D'OH!!

Just had a re-think:

The instructions say that to put it into manual mode you either:

flick swich off/on off on within 2 seconds,

or if you don't have a switch installed then flick the mcb off/on off/on within 2 secs.

So flicking the mcb off would defo remove the live, therefore a permenant live is NOT required, as you said.

Sorry for questioning you mate.

So

All this effort from us and you didn't operate it properly.

Leave the wiring as it is
Wait until it is dark

Follow the instructions

swich off/on off on within 2 seconds

Does it then work?

 

[mrshr]

D'OH!!

Just had a re-think:

The instructions say that to put it into manual mode you either:

flick swich off/on off on within 2 seconds,

or if you don't have a switch installed then flick the mcb off/on off/on within 2 secs.

So flicking the mcb off would defo remove the live, therefore a permenant live is NOT required, as you said.

Sorry for questioning you mate.

So

All this effort from us and you didn't operate it properly.

Leave the wiring as it is
Wait until it is dark

Follow the instructions

swich off/on off on within 2 seconds

Does it then work?

I have operated it correctly, in the dark with the switch in the on position. I'll try it again tonight when I get in but I do think it is faulty.

 

[mrshr]

Tried again with the dusk/dawn setting in a different position and the
timer increased so its defo out of walk test mode but still not going into manual override.

Will whip it out and get it replaced.

 

[EFLImpudence]

Please let us know the result.

 

[mrshr]

OK this is properly winding me up!!!

Got a replacement PIR sensor but it's doing exactly the same as the last one.

Could someone please do me a favour and look at the instructions below for me? Are you sure I've wiring it up correctly?

http://www.free-instruction-manuals.com/pdf/p4795848.pdf

 

[EFLImpudence]

Oh that's disappointing.

I can't see what you could do wrong.

If the sensor works it must be wired correctly.

So...