Outside lighting on pergola

[bassybert]

I've built a new pergola to replace the old one that was attached to the back of our garage. The new one is still attached to the garage and I would like to know if it's possible to use the garage lighting circuit to supply a round 40w(ish) bulkhead in the middle of the pergola and a low wattage (120w) halogen floodlight on the end of the pergola to give a bit of illumination to the garden if needed.

The garage has it's own consumer unity with an RCD, a 16a ring and 6a lighting circuit that's currently using 4 strip-lights totalling less than 800w on it.

I was planning on using 1.5mm t+e clipped through the wall around 12-1500mm up from the floor and straight into a 2G IP55 switch and then on to the respective light from each side of the switch using 1.5 t+e.

Is this practical? Do I need to protect the cable using conduit?

Or as the wiring is external, does it need to be 1.5mm SWA?

Thanks in advance

 

[JohnW2]

Is this practical? Do I need to protect the cable using conduit? ... Or as the wiring is external, does it need to be 1.5mm SWA?

It doesn't need to be SWA. However, 'bare' PVC T+E is not theoretically suitable for exposed use outdoors, since constant exposure to UV light will result in it becoming brittle after a number of years. You could either protect T+E from UV light by putting it in conduit, or else use a suitable rubber-sheathed flexible cable. There are probably other options.

Kind Regards, John

 

[riveralt]

You don't need SWA cable for this job.
You don't say where you are getting the power from for the outside lights.

A. If the garage light switch has a permanent live neutral and earth then tap the power here and follow C:

B: If you can access the junction box or ceiling rose that houses the garage lighting circuit then follow C:

C: run 1mm T&E (why do people want to use 1.5mm cable??) from the live neutral and earth to your new internal garage 2 gang switch which doesn't need to be IP rated - unless you have already bought it.
Then run 1mm 3 core rubber sheathed cable through the back of the back box and wall to each of the outside lights. Silicone the hole both sides.

If you intend to get the power from another source then you will need to take a slightly different approach.

 

[securespark]

River,

The way I read it the IP switch was going on the outside wall not inside the garage.

 

[deadshort]

If your new pergola is backing onto the garage is it possible to bring the wiring in and out of the rear of the switch, that would reduce external cabling.


Regards,

DS

 

[bassybert]

Hi all, thanks for your replies much appreciated.

The switch will indeed be mounted on the outside wall, hence the IP rating - I want the ability to be able to switch either outside light without having to go into the garage.

DS, yes the pergola is backing onto the garage - I was planning on mounting the switch with back plate entry for the supply cable from the garage and then using the top holes with rubber grommets to supply the feed cables to the lights.

Thanks

 

[EFLImpudence]

It may not be advisable to use the top holes.

Is water likely to run down the cables?

 

[securespark]

Top hole, old bean!

 

[deadshort]

Yes, use the bottom holes

DS