Garden lighting

Kyran · May 20, 2014

Hi All,

My first chance to post a question.

I have a client that has asked for garden lighting in multipliable parts of there long garden. How every there CU had not seen the light of day in many years. my main question is how can i effectivly make a sub main while still comply with todays regs. see picture attached. Not performed any tests as yet on CU or examination of circuits. with out changing the main CU as this as this is not something the client has requested. Or is there no other way but to change the main CU.

The situation. The house is about a 100 years old, The client whats garden lighting on the oppersite side of the house to were the CU is, lets say 15 odd meters away. on the veranda there what appear to the the old garden power, the client thinks it was for an old pond now filled in. (how ever it still has power in the cable), which is were i was going to site the new CU (waterproof housing and all the rest). The last garden light would be 46 meters from the new CU (sub main) making it over 60meter from the main CU, obviously calculation are going to have to be make for volt drop ect.

As you can see the man in earth on the main CU looks really same, to small.

What are peoples comments.

amlu · May 20, 2014

garden lighting should not need a separate consumer unit? power it from a fused rcd spur?

davesparks · May 20, 2014

That head looks a bit manky and appears to have what could be a TNCS conversion from the original TNS so you may want to get the DNO out to assess it and confirm earthing arrangements.

And based on the condition, age and type of CU I would be discussing this with the client with a view to getting a proper assessment of the installation as a priority over fitting some garden lights.

Plonker 3 · May 20, 2014

You do not need to install a new DB for the whole installation, merely install a new DB adjacent the existing installation to feed the lights if that's where it need to fed from. Obviously ensure the bonding is upto standard too, jobs a good un.

Kyran · May 21, 2014

amlu said:
garden lighting should not need a separate consumer unit? power it from a fused rcd spur?

Yes i guess thats one way of doing it, however this is two armoured circuits and one clipped to a pergola with three switches so i not really think its suits just a fused spur RCD.

Kyran · May 21, 2014

davesparks said:
That head looks a bit manky and appears to have what could be a TNCS conversion from the original TNS so you may want to get the DNO out to assess it and confirm earthing arrangements.

And based on the condition, age and type of CU I would be discussing this with the client with a view to getting a proper assessment of the installation as a priority over fitting some garden lights.

Thanks for your thoughts thats a good idea, yes its not in the best of shapes. The DNO will do that for NO cost as its the equipment YES?

Kyran · May 21, 2014

Dillb said:
You do not need to install a new DB for the whole installation, merely install a new DB adjacent the existing installation to feed the lights if that's where it need to fed from. Obviously ensure the bonding is upto standard too, jobs a good un.

Thanks for your comment, guess you mean by splitting the tails, YES? As some one else said i will get the DNO to check the head out, earth ect, client permitting obviously. as earth my not be all that good there.

telectrix · May 21, 2014

DNO will replace that head for free. get them to also install an isolator. then you can split the tails, fit a mini-CU and away you go.

Kyran · May 21, 2014

Thank you all for your replies, my first post here and its great to see/read that people read and comment on posts put here. It nice to ono that theres a wider community to ask questions thoughts. especially as i work on my own and fairly new to the trade. Thanks people.

Kyran · May 21, 2014

telectrix said:
DNO will replace that head for free. get them to also install an isolator. then you can split the tails, fit a mini-CU and away you go.

Awesome, i am love the replies and the responses you questions/help. will do that thanks : )

Engineer54 · May 21, 2014

Kyran said:
Thanks for your thoughts thats a good idea, yes its not in the best of shapes. The DNO will do that for NO cost as its the equipment YES?

Can't see anything wrong with the head, apart from it being particularly mucky. It's of a plastic construction by the look of it, so the DNO won't be considering changing it. I can't quite make out if it's been PME'd or not. All they will tell you if they do come out to look, is if it has been PME'd or not.

They will only replace free of charge, if the cut out fuse(s) are DP ceramic 3036, damaged fuse or carriers or the compound sealing chamber is leaking badly etc....

HandySparks · May 21, 2014

Kyran said:
Yes i guess thats one way of doing it, however this is two armoured circuits and one clipped to a pergola with three switches so i not really think its suits just a fused spur RCD.

The installation method and number of switches is irrelevant. What's the total additional load to be supplied? If it's only an amp or two, then an RCD spur off an existing circuit may be the best way of proceeding.

Kyran · May 23, 2014

davesparks said:
That head looks a bit manky and appears to have what could be a TNCS conversion from the original TNS so you may want to get the DNO out to assess it and confirm earthing arrangements.

And based on the condition, age and type of CU I would be discussing this with the client with a view to getting a proper assessment of the installation as a priority over fitting some garden lights.

Hi ya, Thanks for the comment on the DNO and earthing, I have had a conversation with them this morning sent them the picture of the head, and with the ladies brutal efficiency i now have a date for them to come and look at it and replace it. like for like only but who cares its free.. they don't need to suck more power, in fact by the time I have finished there they will be using less and it will all be a bit more efficient.

Thank you.

Engineer54 · May 24, 2014

Kyran said:
Hi ya, Thanks for the comment on the DNO and earthing, I have had a conversation with them this morning sent them the picture of the head, and with the ladies brutal efficiency i now have a date for them to come and look at it and replace it. like for like only but who cares its free.. they don't need to suck more power, in fact by the time I have finished there they will be using less and it will all be a bit more efficient.

Thank you.

They may come and have a look, but replace it because it's a bit mucky, that i genuinely doubt very much!! lol!!
From what i can see from the photo's you posted, i can't see any reason for the DNO replacing this Plastic type service head....