Power for a garden water feature

[roundthebend]

My Dad has asked me to help him install a water feature in his garden. It's a short waterfall thing made of resin with a big reservoir at the bottom end and a submersible pump which comes pre-wired (though with no plug attached).

Its got 10m of cable but this isn't quite long enough to reach from the nearest plug socket in the house. If it had been, I assume we could simply attach a plug and switch it on, making sure that the cable is clipped to an external wall and buried in conduit where appropriate?

However, we're going to need some more cable. Personally, I think we ought to use armoured cable of some sort, and a plug-in RCD.

My Dad has also mentioned wanting to install some spotlights around the feature so we need to think about powering those. His initial thought was to get an outdoor socket kit that could be plugged into the indoor socket through an RCD. Then, the outdoor lights could be plugged into the outdoor socket. We may need more than a double outdoor socket to accommodate all of the lights and pumps. This prompted me to start considering the amount of load on the cable and whether a 13A plug would be able to cope. I suspect not.

Of course, I'm expecting all DIY intentions to be blown out of the water here. It's probably easier if I just ask - what outdoor power can be DIY?

 

[Albert]

I am affraid that you asking the wrong question. The DIY work is not defined by the load but by the nature of the work. A job like the one you described is a notifiable job, meaning that you have to notify the council. The reason is quiet obvious considering that it is an external extension in the garden where the installation will have to be designed to stand the weather.

Going back to your question, I would make sure that a 30mA RCD is protecting this addition, I would berry an armored cable and run it to a point near the features. I would terminate it in a IP rated connection box and from there supply the pump lights etc.

You should calculate the load by adding the watts of the bulbs, pump etc. than by dividing the result by 230V it will give you the load in Amps. There are some factors that you should consider as well as the, already, existing load on the circuit. If the external socket is not on a RCD protected circuit the installed external socket has to be RCD protected.

The correct procedure is after the cables were in place is to test and certify this extension and as said before notify the council.

Otherwise you should call the council before the work was done and they will come and inspect it, this ids not a free service.

For this job, I would strongly recommend to contact a registered electrician.

 

[stuartsjg]

Unless the pump is sending water dozens of feet into the air and the lights arent 500w flood lamps you would be ok with 13A. 13A is around 3000W of power, aka 3kW.

Most of these pond pumps are a few 10's of W and the lights wont be much either.

Armouring every cable would be overkill id say.

Its common to have an IP54+ box nearby where all the plugs are plugged into. An armour, hituf or SY multiflex cable can then be ran to an RCD plug/socket. A timer for lights can be also good.

Another option is to use a 12 to 48v system (12 and 24v common), you can get pumps and light kits which all run from the same transformer mounted indoors. No need for armour or special cables. I also think it avoids the Part P (Eng&Wa) or 17th Ed (Sco) rules as its Extra Low Voltage but im not sure of the rules there.

Stuart

 

[ColJack]

http://www.primrose-london.co.uk/solar-water-pump-180lph-p-3204.html

 

[roundthebend]

I'll read the more in-depth replies later, but that solar pump looks like a good investment ColJack. Do you have any experience with them? My Dad has expressed a dislike of solar powered lights because they tend not to be bright enough but perhaps he's just been buying the wrong things.