Mains Garden Lights Cabling

[Vitesse]

My second post I am getting brave:blush5:

I am estimating a job this week for a customer who wants three garden lights mounted on his fence approximately 75 metres, so each light at approximately 25 metres.

The plan is to run from the consumer unit either 1.5mm or 2.5mm twin and earth through trunking, (dependent on the wattage of the lights and the length of the cable run) internally inside the garage attached to the house where the consumer unit lives. Out through a hole in the garage wall and terminate it into a Wiska box on the outside wall. Then SWA to another Wiska where I can spur off to a light switch at the rear of the garage where there is a utility room to switch the garden lights on and off.

The SWA will be cleated along the gravel boards of the fence and then at each light an additional Wiska to take a flex up to each of the lights.

I haven't done garden lights for ages and last time I did Hi-Tuf was the flex of choice to take up to the lights from the Wiska's. QVS still advertise Hi-Tuf as being a cable still available but TLC advertise NYY-J. Is it the same thing? or can anyone recommend an alternative flex that is UV protected and ok for outdoor use to take upto the lights via the fence posts.

Pretty sure I am going to get the job as I have done some other work for them recently and sitting in the garden terminating some SWA in the impending 30° heat down south seems quite appealing. Better than sitting in a loft space!!!!!!!

 

[HappyHippyDad]

Black rubber flex is suitable for outside use Vitesse. H05RN or H07RN is what I have use, although I can't really see anything wrong with using H05RR either. I'd be doing the same, SWA along the run, into a suitable IP rated junction box and the black rubber flex into light from the JB.

Have you checked the voltage drop and expected Zs for this length of run? At a guess I'd think 1.5mm would be OK but I'd certainly do the calculations first. What is the total wattage of the lights?

 

[Richard Burns]

I agree with the above post.
You are looking to see if the cable is likely to be damaged when you choose the type of cable, Hituff or NYYj is fairly strong but then again so is HO7RNF, though obviously neither are suitable for heavy damage situations.
I assume the gravel boards are made of wood, otherwise you will have problems cleating to a concrete board and would need to use a clamping arrangement.
Volt drop is going to be relevant over that distance.

 

[Paul.M]

And for the difference in price I would use 2.5mm in case they add more lights in the future or a socket at the end of the garden for the Xmas tree lights lol.

 

[telectrix]

And for the difference in price I would use 2.5mm in case they add more lights in the future or a socket at the end of the garden for the Xmas tree lights lol.

or 10mm even in case they want a hot tub. :confused5:

 

[Paul.M]

or 10mm even in case they want a hot tub. :confused5:

Lol, 75m walk back to the house dripping wet! What would the neighbors say???

 

[davesparks]

Hituff is one manufacturers name for NYYJ so yes they are the same thing.
Personally I can't see the point of running T&E in the garage then adding an unnecessary joint in to the run, I would just run the SWA.
Depending in your assessment of the likely mechanical impact damage then you could do the whole run in NYYJ

 

[Vitesse]

Black rubber flex is suitable for outside use Vitesse. H05RN or H07RN is what I have use, although I can't really see anything wrong with using H05RR either. I'd be doing the same, SWA along the run, into a suitable IP rated junction box and the black rubber flex into light from the JB.

Have you checked the voltage drop and expected Zs for this length of run? At a guess I'd think 1.5mm would be OK but I'd certainly do the calculations first. What is the total wattage of the lights?

Thanks for the reply the intention was always to use 2.5mm SWA but as I wrote the post I thought I better put 1.5mm as well in case anyone said why aren't you doing it in that?

I have done the calc for voltage drop and 2.5mm should be well in spec for that distance.

I don't know the wattage of the lights yet but they are not wanting to light it up like Wembley stadium with spot lights or anything more to provide some comfortable light for an upcoming party they have.

I would imagine my local supplier would have H07RN I can't see it on TLC or QVS unless I am missing it?

 

[Vitesse]

I agree with the above post.
You are looking to see if the cable is likely to be damaged when you choose the type of cable, Hituff or NYYj is fairly strong but then again so is HO7RNF, though obviously neither are suitable for heavy damage situations.
I assume the gravel boards are made of wood, otherwise you will have problems cleating to a concrete board and would need to use a clamping arrangement.
Volt drop is going to be relevant over that distance.

Wooden gravel boards fortunately. I am pretty sure the cable will not be damaged as it is all flower beds, so they are not likely to be waving a hedge trimmer or anything like that. Thanks for your reply.

 

[davesparks]

You won't find H07RN anywhere, what you are looking for is H07-RNF. It's often marketed as tough rubber or TRS

 

[HappyHippyDad]

Thanks for the reply. My initial intention was to use 2.5 but I thought as I was writing the post I better put 1.5 as well in case someone said why aren't you using 1.5. 2.5 will be within the spec for voltage drop. I don't know the wattage of the lights but they don't want to light up the garden like Wembley Stadium so not too high a wattage.

I will see if my local suppliers have H07RN. I can't see it on TLC or QVS.

Try here, they sell it and the price is competitive : https://www.electriccable.co.uk/

 

[shanky887614]

Thanks for the reply. My initial intention was to use 2.5 but I thought as I was writing the post I better put 1.5 as well in case someone said why aren't you using 1.5. 2.5 will be within the spec for voltage drop. I don't know the wattage of the lights but they don't want to light up the garden like Wembley Stadium so not too high a wattage.

I will see if my local suppliers have H07RN. I can't see it on TLC or QVS.

you could always explain V drop to them and be done with it and note on the cert about the long run

 

[Vitesse]

Hituff is one manufacturers name for NYYJ so yes they are the same thing.
Personally I can't see the point of running T&E in the garage then adding an unnecessary joint in to the run, I would just run the SWA.
Depending in your assessment of the likely mechanical impact damage then you could do the whole run in NYYJ

Cheers Dave I was considering running the SWA all the way back to the CU and terminating the braid into a little steel box close by and leaving enough on the wires to get into the CU.

Its one of those garages where a little bit of DIY knowledge is a dangerous thing. All the cables from the consumer unit runaway at ceiling height along the wall and then someone has covered them with plasterboard set at 45° between the ceiling and wall. I would have to pull the whole lot down inorder to clip the cable along the wall. Why they didn't box it in with ply I don't know, it would be a lot easier to make additions. I figured it would be a lot easier to find another route out to the garden. I need to go back and take another look before I decide which way to do it.

 

[Vitesse]

Try here, they sell it and the price is competitive : https://www.electriccable.co.uk/

Thanks that's the best price I have seen.

 

[Vitesse]

you could always explain V drop to them and be done with it and note on the cert about the long run

True. There is not much difference in the cost between 1.5 and 2.5 so I may as well just go with 2.5. Plus 2.5 is obviously more expensive so my mark up is a bit better.:clap:

 

[Vitesse]

Black rubber flex is suitable for outside use Vitesse. H05RN or H07RN is what I have use, although I can't really see anything wrong with using H05RR either. I'd be doing the same, SWA along the run, into a suitable IP rated junction box and the black rubber flex into light from the JB.

Have you checked the voltage drop and expected Zs for this length of run? At a guess I'd think 1.5mm would be OK but I'd certainly do the calculations first. What is the total wattage of the lights?

Regarding H055RR my local supplier has H055RR-F available for a decent price. I know you said it should be ok. But specs say it shouldn't be used for long term outside use. I assume they are referring to it being used as a trailing flex? Do you reckon it will be ok clipped up a fence post for about 1.5 metres?

Regards
Tony

 

[HappyHippyDad]

Regarding H055RR my local supplier has H055RR-F available for a decent price. I know you said it should be ok. But specs say it shouldn't be used for long term outside use. I assume they are referring to it being used as a trailing flex? Do you reckon it will be ok clipped up a fence post for about 1.5 metres?

Regards
Tony

Hi Tony,
I was taught in college that black rubber flex is ok to be used outside. Also, some members who are respected on this site are happy to use black rubber flex. I do realise that manufacturers instructions generally say to use H05RN-F if you are going to use it for continuous outdoor use and we do have to 'take account of MI's' as part of BS7671 (134.1.1), but we dont HAVE to follow the MI's to the letter if we deem our design to be safe and it adheres to BS7671.

I'm going off on a bit of a tangent! I would 'generally' be happy to use H05RR-F outside, however I cant actually see how or where you are going to install it. Fot instance I have used it at a stables and have then put it in conduit due to the nibbling mice. I have also decided on occasion to use H07RN-F as I want it to be a tougher for the environment. If it was going to be submerged in water then I would definitely use H05RN-F or H07RN-F, so only you can make the definite decision to use it.

 

[davesparks]

On what technical information are you basing the advice the an RR cable can be used in place of an RN?
Do you know what the difference is and how that affects it's UV stability?

 

[HappyHippyDad]

On what technical information are you basing the advice the an RR cable can be used in place of an RN?
Do you know what the difference is and how that affects it's UV stability?

None.
Yes.
No.

 

[HappyHippyDad]

Actually would be interested to hear about the neoprene?

Black... to help deal with the UV.
Rubber... doesn't become as dry/brittle as PVC in sun.
Neoprene... I Dont know... superior UV resistance qualities?

Also you've mentioned TRS in post 10. TRS can be H05RR so would you use it?