Electric for pump

Hi another question from me.
Didnt even think of this but what do i do about electrics for the pump im guessing you have to wire a plug?
Can it be any kind?
i have electric sockets in shed which is about 9m from pond so would it be easy as just to drill a hole through the wall and put plug into socket i would also get a rcd adaptor just to be safe?
And just trail the wire along fence would that be ok?
How did everyone else connect their pump to electrics?
Any help would be great as i think it might be a job for an expensive electrician!

 

I'm not sure, but I think legally it is a job for a qualified electrician.

However, if you were to do it yourself, then there's a few things to keep in mind.

An RCD is absolutely essential. Unlike fuses/circuit breakers that detect an over-current between live and neutral, an RCD detects a significant change in current between either live and earth or neutral and earth, because that's a tell tale sign that somebody might be getting electrocuted. It only takes a few thousandths of an amp to stop a heart. Nowhere near enough to blow a fuse or trip a conventional circuit breaker, so without an RCD, if you accidentally find yourself standing on charged ground due to an electrical fault, most likely you'll just stand there paralysed until... well, enough said.

The other thing is you have to protect the cable from everything that is realistically likely to happen to it. That includes things like forgetting its there and hitting it with the spade, fences its attached to blowing down in a storm, weather getting to it, rodents nibbling it (my sister's pet rabbit got quite fair into her HiFi power cable before we spotted it). You also need to allow for things shifting about. If you lay 10m of cable on a hot day like today, and pull it tight for a nice neat finish, then come winter there's a chance it will pull itself out of its connectors because copper expands and contracts quite a lot with temperature.

So in summary, you need an RCD, and you need to protect the cable from everything, and allow for a bit of play.

 

Hi thanks for the reply i know theres regulation that you have to go by now but i would like you say protect wire and fit it to a rcd do you think it would be ok or is not wrth taking the risk and get a elecrician to do?
The cable would be on a3ft fench and then goes along the outbuilding which is brick!

 

The best plan is to find a sparky registered with the "competent persons scheme".
If you do the work yourself and something happens your insurance company wont pay out if its not certificated. If you ever want sell the house you`ll have similar problems.
New installations and modification of existing circuits for garden lighting, power, greenhouse and sheds are subject to building regs (notifiable work) and you dont want to fall foul of those

 

I had a short circuit on my pond pump recently.

It was not in the water but in a connection.
It kept fusing even though it was attached to an RCD.
Now if we get a power cut, and the RCD trips, then the pump doesn't come back on, not a problem in itself, but I also have a greenhouse heater attached to the same RCD.
I'm wondering if RCDs are all they are cracked up to be, regarding reliability and safety.

 

That would be because the short circuit was between live and neutral. RCDs don't care about that. An RCD sits back and lets conventional fuses or circuit breakers deal with short circuits.

An RCD wakes up when it detects a current flow between live and earth or between neutral and earth, because that should never happen. That happens when, for example, somebody has connected themselves between live and earth or neutral and earth and is therefore in the process of being electrocuted.

 

I cant actually remember now which two wires were shorting out.
All I know is there was a few bangs at the connection after I put a 13amp fuse in, up until then I thought the pump was U/S.
Even bought a new pump.
But then why does the RCD trip in a power cut??

 

Ok im in two minds What to do as i dont really want to get a electrician but i might have to.
Surely lots people have ponds and dont get electricians? Also the house is rented but landlady lives abroad and has nothing to do with the house but i still want to make sure everythings safe.

 

If the house is rented, that's all the more reason it needs to be a qualified electrician. You will get both yourself and your landlady in a lot of bother if things go wrong.

It wont cost the earth to get a sparky in. Break it down to parts and labour. If you do it yourself, you still have to buy the parts, so that just leaves labour as the difference. I reckon you're looking at about £50 per hour, and I can't imagine a proper sparky taking more than an hour on a job that to him/her will be trivial. There'll no doubt be a minimum charge, but if you ring around you should get a decent price, and it will save you the worry of doing it yourself and risking getting done.

 

When I bought the new pump, the one I didn't need that is, it came with 10 metres of cable.
Too much for me as I have a connection next to the pond, so I cut about 6 metres off.

If you can get to a plug socket with that amount of cable I cant see the problem.

Admittedly you will be probably contravening every rule in the book, (the book wasn't written that long ago),but I cant see a sparky installing armoured cable from your house to your pond for £50, by all means inquire though.

 

Note how I mentioned labour costs, and pointed out that parts cost will be roughly the same no matter who does it, and is of course additional to labour costs.

 

13A is WAY OTT Pete it will give no protection at all to a small pump, 3 or 5A would be safer. But if you look at the bumf that came with the pump or on the pump body you should see what current it draws and base your fuse on that.

 

Regarding RCDs; there's a saying that's fairly well known among those who work with electricity - "It's Volts that Jolts. It's Mills (milli-Amps) that Kills". The human body can take a very high voltage, but not high currents.
RCDs are sensitive to current.

 

I think, legally, that you will be fine with an extension lead above ground - i.e. attached to your fence. Otherwise noone could run an electric hedge cutter in their garden ... whereas if you want to "bury" the cable then you need conduit, armoured cable, or both (and a "electric cable below" tape just below the surface so that the next person digging a hole finds that before the cable ...)

But it would be better to ask a Sparky for a professional opinion.

We had something similar. Previous people had wired the supply to as separate "office" building using cooker flex strung between the buildings, everytime there was a thunderstorm it tripped. The Sparky's solution was to fit a breaker with a slower response (I'm not sure it was the RCD part of the breaker, or the voltage part). That fixed the problem.