Electrical help

[les]

Nothing to do with Minors, ——- I’ve bought a pond pump, it has a very long cable attached, I don’t need it that long but would rather not shorten this cable in case I need to move the pump further away later. However I seem to remember that voltage/amps etc can be lost along the length of a cable, have I got this wrong ? If I keep the length should I not bunch the surplus cable too closely together for heat reasons. Am I over thinking all this ?

[Andmurph]

Hi Les,

You’re of course right. The length of cable will affect the resistance in the circuit, however I’d expect it to be fairly negligible and wouldn’t be at all worried. As for heat when coiling the wires, again I think the effect would be negligible unless you’re making many tight coils.

Cheers

Andrew

[geoberni]

Hi Les
There are losses associated with any length of cable, all of which can be calculated. But unless you're the National Grid, I wouldn't go any further with that...
Generally speaking this loss is proportional to the current flowing through the cable and the cable's resistance. Factors like cable length, diameter, and material choice can influence the amount of power lost as can the dissipation of any heat generated. That's why you shouldn't use an extension reel whilst it's coiled up. At full current use, the cable can overheat and melt the insulation.

For something like your pump, assuming reasonable quality, the cable size should be more than sufficient to allow you to keep the full length.
What I would do though is avoid a tightly wound coil of excess cable, to avoid generating a magnetic field and also have it where it can keep cool, i.e. well ventilated, or even put the excess in the pond.
This is preferable to rolling it up tight and sticking it under some rocks.

[les]

Thank you both for your quick and knowledgeable reply, that has reassured me over the installation of the pump, I shall take notice.

[stuffedpike20]

There are some good solar powered pond accessories available now.
I have got a little fountain in my small pond that throws water up about 18" on a sunny day.
The solar panel is about 6" square, and the whole thing cost about £14 delivered.
It has lasted 3 years so far ,and is still going strong.

[Bill_qaz]

I would suggest connecting via RCD for safety.
It should be quite happy with cable length as supplied fitted to the pump.

[les]

Thanks for more suggestions, I’ll check out the solar stuff. Regarding the RCD, I take the power from a purpose made outlet fitted to an outside wall, not sure I could fit an RCD in, there seems to be just space for the 13 Amp plug. However the house has the latest breaker box fitted under the stairs, I imagine this gives protection ?

[geoberni]

Thanks for more suggestions, I’ll check out the solar stuff. Regarding the RCD, I take the power from a purpose made outlet fitted to an outside wall, not sure I could fit an RCD in, there seems to be just space for the 13 Amp plug. However the house has the latest breaker box fitted under the stairs, I imagine this gives protection ?

RCDs in the Consumer Unit (Breaker Box) have been mandatory in the UK since the 1980s; at first just on the Power sockets, more recently they also put another RCD on the Lighting circuits.
I wouldn't fit a 2nd RCD in line with the house one.
It is generally seen a Bad Practice as it can result in no discrimination between the 2 devices; often the first in circuit, i.e. the one at the Consumer Unit, will trip before the one at the socket.
See para 4 of this document: https://electrical.theiet.org/media/168 ... g-rcds.pdf
In the Regulations, having 2 in series, requires the Consumer Unit one to be a Delayed action device, to enable the one at the socket to trip first.
So just more aggravation. ...

[les]

Appreciate you giving me that information, thanks