Cable diameter for long distance run

[ban-all-sheds]

In what way is it hard to find the answer?

You tell it how long the run is, what the load is, what the relevant installation method/factors are, what the cable type is, and what the voltage drop limit is.

And it then tells you what cable size you need.

I'm absolutely not being deliberately obtuse - what problems were you having using it?

AFAIK the only gotcha it has is that if you specify 3-core cable it will assume 3-phase.

 

[RGi]

What problem(s) were you having?

It is hard to find the answer on the page, the formula would be as easy enough with a calculator. I guess it should be possible to view the page source and get their version of the maths from the HTML or Javascript..?

 

[EFLImpudence]

What problem(s) were you having?

I've just noticed this question.

It seems to be working now.

Previously it stated "no suitable cable size found" - even when reducing the length to very short.

 

[ban-all-sheds]

It is hard to find the answer on the page

Ye Gods.

How much easier does it need to be for you to not find it hard to see that?

 

[JohnW2]

Would that be 4mm diameter, radius or circumference, I wonder?

 

[DetlefSchmitz]

 

[RGi]

Ye Gods.

View attachment 150484

How much easier does it need to be for you to not find it hard to see that?

Perhaps the web page designers should check out browser foraging theory? Thanx for the photoshop pointer to the result, however, it is in a confusing format with all kinds of extraneous and potentially contrary information. I was just looking for the formula to work out the dimeter on an extension lead to run out to the pump in storms, not planning a bunched plasterboard lighting circuit operated at 30 degrees Centigrade.

Which gods BTW?

 

[JohnW2]

... I was just looking for the formula to work out the dimeter on an extension lead to run out to the pump in storms...

It's not really a case of 'a formula', since the characteristics of cables cannot be readily mathematically modelled (at least, not without resulting in impractically complex formulae) - one has to ascertain the answer, directly or indirectly, by reference to Tables of current-carrying-capacity and resistance (hence voltage drop) of cables of the various available sizes under a range of installation conditions (which Tables have largely been derived empirically, because of the problem of mathematical modelling). That's what the on-line calculators do, and you'd have to do the same (refer to Tables) if you wanted to determine the answer 'manually'.

Kind Regards, John

 

[DetlefSchmitz]

OP: You still seem to be assuming that it is the cable diameter (whatever that may be) which defines what you are after, whereas it is the cross-sectional area of each conductor in the cable which matters. This is measured in mm², often incorrectly written as mm. Just so there are no misunderstandings...

 

[ban-all-sheds]

Perhaps the web page designers should check out browser foraging theory?

Ah, I see.

Perhaps people who want to do electrical design work (which is what working out the size of cable needed for a given application is) should check out what's involved rather than railing at websites and other people who do know what's involved when they give them the information they say they are looking for.

Thanx for the photoshop pointer to the result, however, it is in a confusing format with all kinds of extraneous and potentially contrary information.

I cannot argue with your assertion that you are confused.

But I can assure you that you are completely wrong about "all kinds of extraneous and potentially contrary information" - there is not one bit of information which that tool asks you to provide which is not essential.

I was just looking for the formula to work out the dimeter on an extension lead to run out to the pump in storms, not planning a bunched plasterboard lighting circuit operated at 30 degrees Centigrade.

As John said, there isn't one, nor could there be.

And, BTW, you didn't ask for a "formula", you asked how to "work it out".

Which gods BTW?

On balance, I think the ones to which Schiller referred.

 

[Risteard]

I'm looking to make an extension lead of over 60m to run a well pump of of the generator after storms or other power cuts. It needs to run the pump which is rated at 2400 Watts. What diameter cable is needed for this to allow for power loss over distance.

You'd be as well employing a REC to do this job for you.

How are things in the Déise anyway?

 

[aesmith]

By the way, what does that pump actually do, is it for a directly pressurised supply to the house? Reason for asking is that our own well pump, which pumps to a header tank, is only 500 or 600W and only needs to run about 1/2 hour per day.

 

[RGi]

You'd be as well employing a REC to do this job for you.

How are things in the Déise anyway?

Not so bad down here, just getting ready for another winter of globally warmed storms and snows.

I've it sorted now anyways, DIY style, there was a load of advice on here (no money involved- but you still takes your choice) and the extension lead is made, tested and Brexit ready.

 

[RGi]

Ah, I see.

On balance, I think the ones to which Schiller referred.

Wasn't it your man Schiller who said "I am neither Illuminati nor Mason." Did he stop beating his wife as well?

Maybe Thunnor would make a better choice, being a god of thunder, sub atomic particles and electricity.

 

[Risteard]

Not so bad down here, just getting ready for another winter of globally warmed storms and snows.

Good stuff. My mother was from Tramore so I spend a bit of time down that way when I get a chance.