Outside Lighting

[SoulTy1066]

Hi Peeps, would like your opinions on how you terminate cables in the middle of a garden for 12v lighting. My take on it is to run SWA and use the Sheath as cpc, with the SWA being terminated into Resin joints/Branches with submersable 240-12v Transfromers feeding mutliple 12v Spot lights. These 12v joint to be in a whiska box with magic gel or barrelled with adhesive lined Heat shrink. All the cabling to be burried. What about Pratley Boxes?

 

[malcolmsanford]

Are these column lights as somewhere along the line cable is going to be surface somewhere if they are not.

How submersible are the TX going to be for maintenance, inspection. repair etc.

 

[SoulTy1066]

no they are spot lights in flower beds and the IP68 TX will be the only other thing above the ground.

 

[johnboy6083]

if your going to bury the cable, then i wouldnt use the SWA as CPC. the sheath is prone to get damaged, and the armour will corrode over time, possible leaving your lights with no reliable CPC.

 

[Engineer54]

Wired up loads of friends gardens using SWA, but i always use a core as my CPC, and always go down at least 450mm in open areas and reduce that to 300 to 350mm under patio tile work and drive ways. But even then i normally run in ducts/pipe in such locations.


I don't use buried junction boxes, i use the lighting columns or bases of spot lights for terminations and the like and heat shrink them all. ....Normally mount spots on concrete plinths made from filling 75 or 100mm pipe with a 25mm plastic conduit embedded into the concrete plinth to allow the SWA access from ground to light fitting. These things are dead easy to make, just grease the plastic pipe well and the concrete plinths will just tap out of the pipe mould. Longest one i've made was around 350mm, but i reckon you could go longer with a little care.... Certainly adds aesthetic value to the install...

 

[SoulTy1066]

Fair point about using the sheath using a conductor is always better. My main question is the best method of terminating the SWA in a flower bed with a TX at this joint. Then what type of Joint to use on the 12v side of the TX ? Hope this makes my problem easier to understand.

 

[SoulTy1066]

Engineer 54 at the moment i always use Heat Shrink on the 12v side if it just 2 cables being joined, but what is the best option if running more than 1 light off the TX. Do you Heat shrink the 240v joints? Like the idea of the concrete plinths but not able to use them on this project.

 

[Engineer54]

Fair point about using the sheath using a conductor is always better. My main question is the best method of terminating the SWA in a flower bed with a TX at this joint. Then what type of Joint to use on the 12v side of the TX ? Hope this makes my problem easier to understand.

I see your problem now, and it's a difficult problem to overcome from an aesthetic stand point!! The only LV fittings i use that require a local TX are short column type fittings, i suppose for the very reason of the problems your now facing.... The only thing i can think of, is to mount the TX's in an IP rated box on a side wall or fence away from the flower beds. but then you have possible long runs back to the flower beds, and will still need JB's to terminate off to the fittings... Maybe someone else here can come up with an alternative suggestions/ideas!! ....Sorry!!

 

[Engineer54]

Engineer 54 at the moment i always use Heat Shrink on the 12v side if it just 2 cables being joined, but what is the best option if running more than 1 light off the TX. Do you Heat shrink the 240v joints? Like the idea of the concrete plinths but not able to use them on this project.

Yes i crimp and heat shrink all garden lighting connections, especially in Cyprus where humidity and condensation can destroy normal type connectors/connections within a year or so...

 

[ezzzekiel]

Normally mount spots on concrete plinths made from filling 75 or 100mm pipe with a 25mm plastic conduit embedded into the concrete plinth to allow the SWA access from ground to light fitting. These things are dead easy to make

Although commendable and probably looks good - but as an electrician i wouldnt be messing around like that - for a start the customer prob couldnt afford the rates due to the additional effort and materials, there areplenty of readymade available products designed for purpose without resorting to blue peter methods

 

[Dunc]

How many lights are you fitting and what sort of load are you going to be pulling? If the loads are very low with short runs why not site the transformers in a big(ish) IP rated adaptable box and distribute the ELV supply to the light. There'll be less joints using this method at the light fitting and the concerns about acheiving good Zs values will be negated. Only problem is the cable sizes will have to be upped to allow for the lower volt drop tolerances (0.36V on a 12V supply) but this will be easily achievable with LED lamps. Obviously this is only practical if there is a suitable place to hide the 'big' adaptable box.

 

[Engineer54]

Although commendable and probably looks good - but as an electrician i wouldnt be messing around like that - for a start the customer prob couldnt afford the rates due to the additional effort and materials, there areplenty of readymade available products designed for purpose without resorting to blue peter methods

Basically, that's a very similar method that construction contractors use to mount external lighting fittings. Whether they are square or round.... When i knock mine up, i make them in batches, always more than i need, and probably have 4 to 6 of them in a couple of different lengths, knocking around in the shed right now in Cyprus. ....I know they will get used in the future, cost next to nothing to make, are better than anything you can buy off the shelve and will last a hell of a lot longer too..... And last, but by no means least look better too!!!

 

[ezzzekiel]

of which i would tend to agree and am cosidering some for my garden quite like the idea - just saying i personally wouldnt be prepared (unless the additional profit margin was there) to go to them sort of lengths for a customer

 

[Engineer54]

I see your point, these were all made for myself and friends. And as i said dead easy to make and don't take that long to make, setting time making up most of the time!! lol!!

You could always knock a couple up, as samples to show customers, ...set a price on them, then you may be making more out of the job, than you were before...

 

[SoulTy1066]

every thing really needs to be buried except the Tx as all the plants nearby are deciduous and will die back just leaving the spot lights. The idea of IP Boxes on the wall is good but the nearest wall or fence is 20 metres away.