Wiring Outside Lights

[tfldatomax]

Morning All,

I was just looking for a bit of advice on wiring up two outside lights. I would like to take power from an existing socket in the kitchen to a FCU and then 1.5mm2 HI-Tuf or similar through the wall to the outside and to a junction box for the first light then onto the second light.

Does my wiring on the picture look correct.

I live in Scotland so no part P issues but obviously want to do it safely.

Outside Lights Wiring

• tfldatomax
• 29 Aug 2013
• 1

Thanks very much
Trevor

 

[riveralt]

Firstly you need to make sure that the Spur you are taking from the Ring Final Circuit is not a spur from a spur.
Secondly, you don't need 1.5mm hi tuff or other expensive cable a 1mm²black rubber cable will do.
Thirdly, you don't need to run the circuit through a junction box - just run it through the first PIR light.
Fourthly, use a switched FCU - this will give you the facility to over-ride the PIR and have the light on permanently.
Finally, here in England we get shot at dawn for having a 500w light - the limit is around 120w. You can toast your sausages on a 500w light.

 

[PrenticeBoyofDerry]

The set up looks okay and depending on the enclosure and terminals of the light fitting you buy, it could be possible to use the first light fitting to connect second light rather than a junction (which will need to be suitable for environment). The lamps output could require to be amended, as there are building regulations concerning the watts allowed per lamp. Which I call being 120W per lamp.

 

[tfldatomax]

Riveralt,

thanks for the quick reply.

The socket I will be adding a spur to is not already a spur (I don't think! - it has two cables connected so assuming this is on the ring main - any other way of checking? its a 7 year old house so don't think it would be a spur itself and then supplying another spur...if that makes sense??

I will use 1mm2 rubber cable as that will be far cheaper - thanks.

Got confused with the JB requirement as thought connecting through the light would mean they were in series but I see now that is not the case so will leave out the JB and use a switched FCU as you suggest.

Yeah I was thinking that 500w may be a bit too much...I will maybe down grade the bulb to 120W and keep the sausages for the BBQ..

So with the changes in place the following is what I will do:-

Untitled

• tfldatomax
• 29 Aug 2013
• 1

thanks
Trevor

 

[PrenticeBoyofDerry]

2 sets of cables does not confirm it is a ring circuit.
Could well be a radial or a spurred spur.
The correct way to find out is investigation and testing using approved test equipment.
Even if the property is only 7 years, old does not mean alteration have not been made.

http://www.tlc-direct.co.uk/Book/8.4.2.htm

 

[riveralt]

The socket I will be adding a spur to is not already a spur (I don't think! - it has two cables connected so assuming this is on the ring main - any other way of checking? its a 7 year old house so don't think it would be a spur itself and then supplying another spur...if that makes sense??

It is difficult to tell without further investigation and or testing.
Assuming it is a Ring final Circuit - 2.5mm ² T&E and 32Amp MCB then two cables in the socket you intend to use means it is highly likely to be part of the RFC.
When spurs off the RFC are created you would normally have one socket with three sets of cables and the spur socket with one.
One other thing you will need to consider is to ensure that the outside circuit is additionally protected by an RCD.

 

[tfldatomax]

Thanks for the replies guys. The house was new when I moved in and I have asked the builders before what kind of circuit the ring main was on so I am pretty sure it is a ring circuit.

We did ask for additional sockets to be fitted at the time of build but this was not one of them so I don't think it would be a spur form a spur.

Regarding the RCD protection....all the sockets in the house are protected by an RCD at the consumer unit....is this suitable or would I need to fit another RCD into the setup?

thanks again
Trevor

 

[riveralt]

Regarding the RCD protection....all the sockets in the house are protected by an RCD at the consumer unit....is this suitable or would I need to fit another RCD into the setup.

Yes your set up is fine.

 

[PrenticeBoyofDerry]

The house was new when I moved in

Did you receive any document regarding the electrical install when purchased?
As you may have a schedule of test results, that will identify the characteristics of the circuits, also I would expect a circuit chart to be visually displayed at the consumer unit, which should also identify the circuit type.

 

[tfldatomax]

Hi no didn't receive any documents regarding the install when I moved in...never thought to ask for one either but guess I should have done....

I will have a look near the CU and see if there are any diagrams there. Thanks for your help.

cheers
Trevor

 

[OuterSpaceHopper]

Hi Trevor,

I'm installing my exterior lights with 3 core and earth hi tuff, as this will allow me to pass a switched earth outside to allow switching the lights on from inside the house.

Another option is that some types of security lights come with internal electronic control that allows the lights to be toggled on or off by means of quickly cycling the circuit breaker, and so don't need a switched live for manual override.

Might be something to think about whilst your planning your installation.

I don't know if I needed to, but I bought the hi tuff as the Twin&Earth that I removed from the outside walls had perished something rotten and was tripping the circuit breaker.
The hi tuff was expensive and not easy to come by either.
If you lights are low power, perhaps the cheaper outdoor 'pond' cable will do the trick? Although I'm not sure where you'd stand using 0.75mm2 cable on low power lights if iti s possible that one day the bulbs could eventually be replace by high energy lamps overload the cable?

 

[riveralt]

switched earth

What's one of them?

Another option is that some types of security lights come with internal electronic control that allows the lights to be toggled on or off by means of quickly cycling the circuit breaker, and so don't need a switched live for manual override.

Really I never new that.

If you lights are low power, perhaps the cheaper outdoor 'pond' cable will do the trick? Although I'm not sure where you'd stand using 0.75mm2 cable on low power lights if iti s possible that one day the bulbs could eventually be replace by high energy lamps overload the cable?

Must be pretty high energy lights.
Do you know what you are talking about?

 

[securespark]

Two cables into a light fitting may not go, depending on the kind of cable entry.

 

[OuterSpaceHopper]

switched earth

What's one of them?

No No No No No No No!!!!

Sorry folks, I didn't mean switched earth! What a disasterous slip of the keyboard!
I ment switched live!

 

[OuterSpaceHopper]

If you lights are low power, perhaps the cheaper outdoor 'pond' cable will do the trick? Although I'm not sure where you'd stand using 0.75mm2 cable on low power lights if iti s possible that one day the bulbs could eventually be replace by high energy lamps overload the cable?

Must be pretty high energy lights.
Do you know what you are talking about?[/quote]


Nope! Not at all!

It was more of a question really. The lights are rated at 1200W maximum bulb size, even though they were to be used with 23W CFL lights in.
I'm not sure how many 1200W bubs you could run from a run of 0.75mm2 cable?

I guessing that installed cable has to be capable of meeting the maximum load from the fixed equipment?

In the end I bought new security lights that have a maximum size of 120W stamped on them, and I bought the higher rated 1.5mm hi tuff cable, so no worries about rating I don't think?

The hi tuff is hard to work with as it is so fat and stiff, but the security light gland clamps it tight so no chance of leaks.

I would have thought that a junction box will be required outside of the lamp if extra cable is required for downstream lights. I certainly couldn't fit any extra cable in the glands that came with my lights.