Current Carrying Capacity of cables with different voltages

[iamgary25]

Does the current carrying capacity of cables change on what voltage your using??

2.5mm can carry 27a at 230v
would this be the same for 1000v
could someone please explaain this whole process please
Confused lol

Grant

p.s i'm a student

 

[telectrix]

current capacity depends only on the cable csa, be it at 12V, 240V, or 24,000V. it's the power transmitted down the cable that increases with voltage. so, for example 5A @12V is ( 5 x 12 ) = 60watts, but 5A @240V is 1200watts.

 

[Dizzy_Maskell]

Just the insulation of the cable that will need to alter according to voltage

 

[iamgary25]

ok so the insulation just needs the correct voltage rating, just like you'd do for selecting electrical equipment and the current is the exact same, just the power differs, so the high the voltage the less power you can use with it?

 

[Marvo]

Current flow is a physical quantity of electrons flowing though the wire every second. If one amp is flowing down a wire then 6.25 billion billion electrons are flowing down it each second. The number of electrons flowing is what causes the wire to get warm and this is the limiting factor, the voltage pushing them along makes no difference to this. Wires are rated according to their temperature limits, their maximum current is that which causes them to get close to this temperature.

As pointed out the limiting factor with voltage is how good the insulation protecting the wire is.

 

[Darkwood]

The good old classical explanation there marvo ....il resist getting all quantum and correcting it as its good enough for the OP to get an understanding

I was tempted though but your a super power now with an urge to test your abilities :30:

 

[Silly Sausage]

Ah...I can see the 'What is electricity' discussion looming on the horizon.
I'm out!

 

[Darkwood]

Na not today Archy its quiz night at the local

 

[Marvo]

The good old classical explanation there marvo ....il resist getting all quantum and correcting it as its good enough for the OP to get an understanding

I was tempted though but your a super power now with an urge to test your abilities :30:

Lol, the answer was pitched at the level of the question. As you rightfully point out it's not going to win any science awards but understanding electrical theory has to start somewhere. This was the kind of explanation that's been taught to apprentices including myself for decades so It's a good place to start. We all believed in Santa then in later years were told it was a lie then we learn that even by looking for him we could change the fact he did or didn't exist

 

[Thefailsafe2012]

Lol, the answer was pitched at the level of the question. As you rightfully point out it's not going to win any science awards but understanding electrical theory has to start somewhere. This was the kind of explanation that's been taught to apprentices including myself for decades so It's a good place to start. We all believed in Santa then in later years were told it was a lie then we learn that even by looking for him we could change the fact he did or didn't exist

You mean he's not real? :sad:

 

[FAA Greenie]

An Amp is an Amp, is an Amp, regardless of what's pushing it, or pulling it. Think about high voltage transmission lines and the amount of power that they are able to deliver...

 

[plugsandsparks]

arrrr but what speed does that electron manage as its whizzing its way down the cable?

I remember asking this question at school when we were doing O level physics, even though i had to "go with it" for the exams, i really could not see one electron bothering to make its way all the way from Drax power station to my house.

never made sense to me.

 

[sparky351355]

300,000m/s

 

[FAA Greenie]

Well if you really want to get into it, a single electron doesn't have to move along much of the conductor at all, it only has to dislodge another electron from it's neighbouring atom and take it's place. It can then stay in it's new home forever if it's lucky !!!

 

[Darkwood]

In Ac circuits the electrons vibrate pretty much around their own original position so no actual electron migration and in DC the electrons move so slow it make a snail look fast ....... look up 'speed of electricity' on Wiki and learn why everything you are taught is dumbed down and a lie just to make sure you dont get brain overload ..... classical physics is all you need to know .... advanced physics first rule is forget all the crap you were ever taught.

@sparky 351335 .... 300,000m/s is the speed of the propagation of the EMF not the electrons whizzing around as your answer implies if your going to google it make sure you understand what you read..