Adding a PIR override to an existing landing light

[jason69]

Help please!

In addition to the existing two location multiway switching for our landing light (i.e. from wall switches upstairs and downstairs) we want to add a presence detector or PIR to switch on the landing to turn the light on for a timed period when it detects movement e.g. child walking out on to landing at night. We currently have a 3 gang 2 way switch in the hall way (porch, hallway and landing lights) and a 2 gang 2 way switch on the landing (hallway and landing lights). We want the PIR to turn on the light independently of the other switches and ideally only in low light.

I've been advised that an MK K4199 WHI movement detector used with the K4202 WHI programmer could be used to switch on the light, which (apparently) could not be set up as part of the two way switching but it could be used to override this and switch the light directly from the same circuit.

My question is how do you wire up an override in an existing swithced circuit, or is there another way of achieving the same result? A simple diagram to illustrate would be appreciated!

I'm also looking for a product that will gently brighten the light on when switched on and fade the light to off when a controlling switch is opened either in-line, in pendant fitting or from a switch - can anyone recommend anything?

 

[breezer]

wiring it, easy.

but i would say your idea is

1) costly

2) Flawed.

I say costly, but that depends on how much you want to spend.

I say flawed becuse it will dim up and down, although a novel idea where does it brighten too? and dim down too, and would you want it that bright? (wake you up)

I do however have a simple easy solution.

fit a 15w lamp switched independantly, its not too bright, and not too dark, but you sure can see by it.

 

[davy_owen_88]

Well a PIR goes between the permanent live and the live terminal of the light (functioning very much like a normal light switch only activating upon detection of movement).

You already have a permanent live going to the switch and a switched live going to the light. If you want the PIR to switch on the light even when the switch is in the off position then just connect the PIR between the permanent live and the live terminal at the light. Take the permanent live from the common terminal at the switch and put the output of the PIR to L1.

Davy

 

[breezer]

are we not forgetting something?

 

[bernardgreen]

Well a PIR goes between the permanent live and the live terminal of the light (functioning very much like a normal light switch only activating upon detection of movement).

You already have a permanent live going to the switch and a switched live going to the light. If you want the PIR to switch on the light even when the switch is in the off position then just connect the PIR between the permanent live and the live terminal at the light. Take the permanent live from the common terminal at the switch and put the output of the PIR to L1.

Davy

The PIR sensor is almost certainly a three wire device

Live IN
Neutral IN
Switched live OUT


Take the permanent live (loop) to the PIR Live IN
Take the neutral loop to the PIR Neutral IN
Take the PIR Switched Live out to the switched live in the ceiling rose.

Use three core and earth and take it via a three pole isolator switch.

 

[sparkyspike]

Firstly, some dimmer switches will fade up the light gently for you.

Regarding the sensor, a cheaper option would be to get a ceiling mounted PIR sensor. This acts as a simple switch which you can wire directly into your lighting supply and then on to the light. To wire this into the existing light you can add a 2 way switch. Put the existing feed into Com. Com - L1 will activate the feed to your existing switch which is 2-wayed downstairs. Com - L2 will disengage the existing switch and liven up the PIR which will then feed the light. You could use a 3 gang switch upstairs to do this. There will be two feeds to the light.

 

[davy_owen_88]

are we not forgetting something?

The PIR sensor is almost certainly a three wire device

Live IN
Neutral IN
Switched live OUT


Take the pehrmanent live (loop) to the PIR Live IN
Take the neutral loop to the PIR Neutral IN
Take the PIR Switched Live out to te switched live in the ceiling rose.

Use three core and earth and take it via a three pole isolator switch.

Sorry, I left out the neutral/earth connections because I assumed that when he buys the PIR he would follow their instructions and just apply the logic I gave hoping the comparison to the switch wiring would give him a better idea of the way it would be wired.

 

[breezer]

bingo, the neutral.

But you are all forgetting one thing (almost) with a pir it will switch on and off in daylight (waste)

get one with a built in light sensor

what happens when the light comes on? the light sensor will think its daylight and turn off.

but my one out side doesnt do that

thats because its not in a confined space seeing its own light.

ok it may work, but it may not.

i would suggest have a pir, and a light sensor mounted outside feeding the pir, so in daylight it deosnt work and at night it does, but then its costing a few £ (ok not extortionate) but i bet its more than the op wants to spend

 

[sparkyspike]

Hence my suggestion that you can give it its own switch so you can turn it on when you go to bed. Dusk sensors don't work well indoors and you may not want it to work at 5pm in the winter.