Sensored lights

[Jordan Mccreery]

I've been asked to do a Joan at my friends house and she wants me to put up and new light at the side of her house that is sensored but wants it on with the existing lights at the front of the house that aren't sensored. Is this possible?

 

[Darkwood]

Welcome to the Forum Jordan..




Edit - Thanks for filling profile in, you good to go in this section

 

[Spoon]

I presume that what you are saying is that your friend wants a light with a PIR at the side of the house what is switched on the same time as the front light? Is this correct? If so, it is possible.

 

[Spoon]

Your profile says you are a fully qualified electrician, what can you tell us about the existing light circuit?

 

[Darkwood]

If you can give us some clarity to exactly what she wants to happen here ..

- Front O/S lightswitch brings on PIR light as an over-ride
- PIR light stays as a independent fitting working off its sensor regardless of front lights been on or off
- Front lightswitch powers the sensor light and when switched off the sensor light will not operate ( not the best method here as the timer circuits fire up everytime you switch the light on but might not be an issue)

 

[Jordan Mccreery]

He wants this new light to come on at night via pir if someone walks up the side of the house but wants it on the same circuit as the lights on the front of the house which is just 4 normally switched spotlights

 

[Darkwood]

He wants this new light to come on at night via pir if someone walks up the side of the house but wants it on the same circuit as the lights on the front of the house which is just 4 normally switched spotlights

Just wire into the supply to the front lights (permanent L/N) via a an isolation point like a spur (Allows for isolation for safe lamp change).

TBH I don't see why it has to be on the same circuit if the switching has no influence on the PIR fitting although it would be good practice to keep all the O/S lights on the same circuit, if the CU is close by then pick up a mains from there off the lighting mcb for the front lights.

The PIR will have a adjustable light level sensor so shouldn't operate during the day anyway and if you want it on with the front lights only and off when they are not switched on then loop a cable off the spot light to feed the PIR fitting... load calcs etc confirmed of course.

 

[Spoon]

Is a RCD required?

 

[HappyHippyDad]

Just wire into the supply to the front lights (permanent L/N) via a an isolation point like a spur (Allows for isolation for safe lamp change).

TBH I don't see why it has to be on the same circuit if the switching has no influence on the PIR fitting although it would be good practice to keep all the O/S lights on the same circuit, if the CU is close by then pick up a mains from there off the lighting mcb for the front lights.

The PIR will have a adjustable light level sensor so shouldn't operate during the day anyway and if you want it on with the front lights only and off when they are not switched on then loop a cable off the spot light to feed the PIR fitting... load calcs etc confirmed of course.

I think from his opening post Jordan wants the light to be switched on by a sensor AND to have the option of switching the light on and off with the same switch as the other outside lights are already on. Is that right Jordan?

Yes, it is possible. It depends where the permanent live (PL) or N is? If the PL is in the present outside light (along with the SL and N) then you'll need to take a 4 core flex from that light (PL, SL, N and E) to the sensor. If the switch has the N in it (which it may well do being for an outside light) then you'll need to take a 4 core flex (or 3 core and E if not subject to the weather) from the switch to the sensor.

I would always install a sperate switch when installing a sensor just so that if the sensor becomes faulty you can switch it off if needs be. With the above you wont have a switch to do this so would be reliant on the MCB, so you could make the present switch into a 2 gang switch so the extra gang swithes the PL to the sensor, however this option would only work if the neutral is already in the present switch.

You'll have to make sure that the sensor has a seperate terminal block for the SL, which most seem to have.