External Supply

[Voogy]

Hi all,

New here so I hope I’ll find it useful!

I am planning on building a garden pond in the next couple of months and obviously I need a power supply for the pump etc.

I know the cable has to reinforced and buried at least 500mm with warning tape 250mm above that.

My garden is quite strange in that I have a patio then a steep ‘hill’ 2 meter(ish) then sort of levelling off(ish) I also think there is drain works under the patio leading across most of the length.

So if there is piping beneath does the armoured cable need to run beneath this or can it placed on top even if less that 500mm?

Where I lead the cable up to the supply obviously this will need to be metal conduit are there any regs as to how deep this needs to be sunk (simply 500mm to meet the cable)? Are there any height restrictions on the waterproof socket (minimum height?)

I have no spare outlets on my CU so will need a 2 way RCD CU adding? I am competent in wiring this all together but any idea of the cost (very approximate) for connecting new tails to this?

Any other points to consider?

Thanks in advance sorry it’s such a long first post hehe

 

[ericmark]

You are asking about regulations so first to consider is Part P.
Although I like many others don't like Part P the problem is not the regulation/law it is the cost. There are two ways to satisfy Part P for the electrician he can become a member of a scheme which allows him to post off his installation certificate and the scheme operator sends you a completion certificate at the same time as informing council and it is all done after the job is completed.

However if anyone not a member wants to do notifiable work then he has to inform council before he starts and he in Wales (England and Ulster may have non unified charges) we get charged £100 plus vat for first £2000 worth of work. Plus now they can pass on any charges for any out work so if you can't sign your own installation certificate then you may get an extra charge. So in real terms unless the work involved is over around £300 it is not worth DIY if you want to keep within the regulations.

Since you want to follow regulations then you must realise the LABC may ask for things not quite as laid down.

522.8.10 Except where installed in a conduit or duct which provides equivalent protection against mechanical damage, a cable buried in the ground shall incorporate an earthed armour or metal sheath or both, suitable for use as a protective conductor. The location of buried cables shall be marked by cable covers or a suitable marking tape. Buried conduits and ducts shall be suitably identified. Buried cables, conduits and ducts shall be at a sufficient depth to avoid being damaged by any reasonably foreseeable disturbance of the ground.
NOTE: IEC 61386-24 is the standard for underground conduits.

AGRICULTURAL AND HORTICULTURAL PREMISES do have a regulation it states:-
705.522 Selection and erection of wiring systems in relation to external influences
In locations accessible to, and enclosing, livestock, wiring, systems shall be erected so that they are inaccessible to livestock or suitably protected against mechanical damage.
Overhead lines shall be insulated.
In areas of agricultural premises where vehicles and mobile agricultural machines are operated, the following methods of installation shall be applied:
(i) Cables shall be buried in the ground at a depth of at least 0.6 m with added mechanical protection
(ii) Cables in arable or cultivated ground shall be buried at a depth of at least 1 m
(iii) Self-supporting suspension cables shall be installed at a height of at least 6 m.

However you are not really an AGRICULTURAL AND HORTICULTURAL PREMISES so really this does not apply. I don't have a copy of IEC 61386-24 so can't help there but as far as I can see there is no Electrical regulation giving a depth it just says it must be laid in a way not to be damaged. This could be to follow the route of some edging stone. In my case it follows the boundary fence.