Outdoor downlights in soffitt, PIR & timer query?

[higgster]

Hi Guys,

Im after some advice please,

I am planning on installing some spot lights under the soffits in my new extension.

The question I have is, is there a product available to have them on a PIR sensor and timer. ie the timer set to for lights on from 19:30-20:00, then outside these times the PIR sensor will work?

Thanks

Matt

 

[electronicsuk]

You should be able to run a PIR and timer in parallel, so there's really no need for a product that combines the two. Alternatively, you could consider a hi-lo PIR that will dim the lights to a user-adjustable brightness during the night, and bring them up at full brightness when the PIR is activated.

 

[EFLImpudence]

Untitled

• EFLImpudence
• 16 Sep 2011
• 2

This is a single channel programmer/timer such as-

Edit - I have deleted the example as I couldn't find a current rating but an immersion timer would be alright.

which you can switch on or off permanently as well if you want.

And a stand-alone PIR.

 

[higgster]

Thanks for the replys, I hadn't considered having them on all night, good idea though. will have to consult the boss (wife!) Is there any brand/make of PIR that you recommend? Presumably if they are low voltage the cost should be minimal having them dimmed all night?

Cheers

 

[Adam_151]

Presumably if they are low voltage the cost should be minimal having them dimmed all night?

low volatage is not the same as low wattage.

It is the wattage that determines running costs, not the volatage band that it operates at (which affects install cost).

Having a lamp dimmed doesn't save as much as you might imagine... a lamp at quarter brilliance is probably at somewhere around half power. A better alternative would be to dim the light level by having several switched groups.

Low wattage lamps should be used anyway, but these will not work with any controls that try and dimm the load, and could cause problems if the switching part is solid state, a mechanical contactor is best for such loads

 

[higgster]

Whoops, to early in the morning, brain not thinking properly!

So would a Hi-LO PIR work with low energy say 7w or LED lights?

 

[electronicsuk]

Whoops, to early in the morning, brain not thinking properly!

So would a Hi-LO PIR work with low energy say 7w or LED lights?

If you buy LED lamps specifically designed to be used with conventional dimmers then yes, it should do, although you'd be looking to pat ay least £25 a lamp.

I wouldn't bother with dimmable CFLs, as they don't perform all that well in the cold, and dimming them won't help with their reliability.

 

[Adam_151]

Unless you start looking at specialist kit then no. A standard hi-lo PIR will not dim an LED or CFL, it best it'll not work, at worst either the hi-lo PIR or the LED/CFL drivers/ballasts will be damaged.

You can acheive the same functionality but it won't be cheap!