PIR controlled external lights

[Jupiter01]

Hi,

Is there a best practice that should be followed on the above when it comes to a switch? i.e. should there be a switch, fused spur and can I use regular 1.5mm cable for this and make it part of the lighting circuit.

Thanks in advance.

 

[ericmark]

In the main we are not permitted to use any electronic control unit as an isolator there are some special exceptions. But with non rotating equipment there is very little to say where the point of isolation should be. It is down to design. In an office where we want to re-lamp without turning all lamps off using lighting track above the suspended ceiling with a row of sockets so each fitting can be isolated in turn is common. However we would not do this in a house. Having a PIR in a room or other in doors place often we only have the MCB that we can lock off, however outside where we may get water problems then either a FCU or plug and socket so one can remove it from service and continue to use other lights is the norm.

Since the introduction of RCD protection having an isolator which isolates all live wires is more important, not just the line but also the neutral.

 

[Jupiter01]

Thanks for the prompt response. I like the idea of a FCU (I was referring to the same with a Fused Spur...).
Would it make sense to have this at light switch height and is it wired just like a light switch? e.g. 1.5mm cable to light fitting

 

[Jupiter01]

Hi, Can someone please confirm the above arrangement. Have I got this right? Thanks

 

[Simon35]

Thanks for the prompt response. I like the idea of a FCU (I was referring to the same with a Fused Spur...).
Would it make sense to have this at light switch height and is it wired just like a light switch? e.g. 1.5mm cable to light fitting

If it's part of the lighting circuit I wouldn't bother with a FCU, just a double pole switch so you can isolate both L and N (if you get water ingress you can get RCD tripping even with the L isolated). If you already have the FCU then it's fine to use it, they are usually (always?) double pole switching.

Standard twin and earth is fine if you are going through the wall straight into the back of the light, otherwise you need a cable suitable for outdoor installation.

Take your lighting circuit to the switch first, then the light.

 

[Jupiter01]

That's great. Thanks for the response. Much appreciated!

 

[Jupiter01]

Just so I have this clear in my mind - the feed cable will come to the switch and a further cable will then go from the switch through the wall, outside and connect into the back of the light fitting.

The next light will then have its feed cable coming from the switch.

 

[Simon35]

Just so I have this clear in my mind - the feed cable will come to the switch and a further cable will then go from the switch through the wall, outside and connect into the back of the light fitting.

The next light will then have its feed cable coming from the switch.

Yep.

Lights don't need to be wired in a ring, and aren't usually, so you can come out of a nearby light fitting or switch, wherever there is a live, neutral and earth and you can connect.

All, of course, needs to be tested. On the off-chance that you don't have all the required test equipment, you should at least determine that the earth you pick up is actually connected to the main earth terminal at your consumer unit.