Practical current capacity per mm² for copper wires: 1mm², 1.5mm², 2.5mm², 4mm²?

What is the maximum current that can be sent through a cable with a diameter of 1mm 1.5mm, 2.5mm, 4mm ... what is the practical conversion factor? Please do not write that these parameters can be found in the tables in terms of insulation, environment, I am only interested in what practical conversion factor should be used, to keep some reserve, but at the same time so that the cable is not too thick.

I have the "Cable load capacity" table from 1984 technician's calendar, you can rely on it as you wish:
Cross-section [mm2] / Current [A]: 0.75 / 10 # 1/12 # 1.5 / 16 # 2.5 / 21 # 4/27 # 6/35 # 10/48 # 16/51. As I said, this data is quite old. You can rely on them or not, and the figures are for copper conductors.

the strength of the cable is not important (actually 5 - 10 A / mm ^ 2) but how much power from the amplifier you will leave on the cable. To know this, calculate the resistance of your cable and decide for yourself whether you want to lose 1% of power or 10% of power. Let me give you an example. I use a 6mm ^ 2 cable with a length of 22m for a 2 ohm impedance column. the cable is about 132mohm, i.e. I trace about 7% of the maximum power. I think it is reasonable, although the 7% is 350W (in practice it is less because the average impedance is higher than the rated one), because the loudspeaker is 5kW. The cable costs around PLN 300. If I had paid 600PLN, I would have lost 150W. Do you think that this road pays off?

Hello

In general, I assume the cable load is 10A per mm ^ 2.
This converter can be used for transformer windings as well as for other applications.

Chloride

Hello
You must have exaggerated with such a converter in transformers,
wind the transformer (primary winding first from the core) using such a conversion factor. I wonder how long this luck will last?
Almost all the data is true - but when the wire is placed freely in the air.
Cooling in transformers is difficult, therefore the conversion factor is even only 2 A mm ^ 2.

testownik wrote:

Please do not write that these parameters can be found in the tables in terms of insulation, environment, I am only interested in what practical conversion factor should be used, to keep some reserve, but at the same time so that the cable is not too thick.

As you can see from the above deliberations, it cannot be completely cut off from
the environment. :(

-
greetings

and I found something like this :)

http://www.hal.trzepak.net/faq/winxp/obciazalnosc.htm

you can read

It all depends ...
- what material of the cable?
- how long did he live?
- what load? Heater? Heavy starting engine?
- how long is the cable to work under load? 10 min? Whole day ?
- where is it? in a cold basement or on a sunny wall?
etc etc ....

So there is no simple answer

neo_dc wrote:

It all depends ...
- what material of the cable?
- how long did he live?
- what load? Heater? Heavy starting engine?
- how long is the cable to work under load? 10 min? Whole day ?
- where is it? in a cold basement or on a sunny wall?
etc etc ....

So there is no simple answer

That's what the standards are for

Moderated By c2h5oh:

A theme from 2003. Please pay attention to the dates.

Regulations point 3.1.19. Do not send messages on archival topics if this is another question, in particular other than the questioning person. Out of respect for the questioner, create your own topic. You can only add a solution to the problem.

Each spool of cable should have a sign with a description of the cable parameters in the store - such an EU requirement, sellers do not do this as requested and sometimes they have a problem, and there is one quite important parameter written, among others, such as: "Maximum conductor resistance in temperature in ? over a length of 100m or 1km "(" So the copper content in copper ha ha ").

I am just browsing Allegro wire auctions and so far they have provided this parameter only in one auction. But there are wonderful other parameters given, and what beautiful descriptions: quality cables.

Moderated By c2h5oh:

You are responding to a topic from 2003. Don't you think the reality has "changed a little"?

@ 60jarek it looks like that even a very small percentage of impurities spoils the conductivity a lot. Copper for wires must be very pure to be able to use it at all, therefore copper refining processes have been used in the industry for a long time, which allow to obtain the required purity, for years there was no problem with this. Nowadays, "creative entrepreneurs" I am surprised that we do not have mass fires yet because of this, but while it is easy to sell a shitty USB cable and count on the fact that the customer will not come with a complaint, then with more, the deceived customer will fight for own.

0.1% iron will degrade the resistance of the wire twice, such a wire used as instead of normal copper will simply burn out
Here is an example of how other alloying elements are harmful


I once checked a bad USB cable - apart from a small cross-section, the resistivity was much higher than for copper.

jarek_lnx wrote:

the resistivity was much higher than that of copper.

I noticed one of the very important parameters of the cable that is omitted when buying, and I consider it important.
People buy the cheapest crap, and then they are surprised at the end result. You can count for yourself what happens by the difference of a few ohms in the installation - I have given my attention what to pay attention to when buying or choosing a cable.
I do not get into discussions about the alloys and the composition of alloys for the production of the conductor.

If you are familiar with the cables currently offered on the market, advise him what to use.
Let the author describe in detail the place where the lamp works and the cable track, which way and how it will lead. (under plaster or otherwise).
A line or maybe one strand. What wire insulation to choose besides referring to standards that he does not know.
He can give a specific type of wire - as we will know all its nuances of installation.

jarek_lnx is why you should check this parameter when you buy it, and I am not a metallurgist, so I will not ask the seller for the composition of the metal conduit.

Added after 17 [minutes]:

In our society, when choosing a cable, only the cable cross-section is taken into account, and whether for plastering or outside, the rest of the things are neglected.
"They buy the wrong cable - surprised that he often blows out the fuses and heats up - so they advise him to use a thicker cable - the effect is that the installation is even worse. And it was enough to buy a cable with the appropriate parameters and enjoy the effect of our installation for years"

The topic concerns the selection of the wire cross-section for this lamp, but no one mentioned, for example, where you want to connect this lamp, at which point in its home installation, etc. It turns out that it has 0.7 mm in the house, and he will connect the lighting to a socket in the house 1, 5mm - and we already have a big problem. And we ignore the problem of security entirely - security. What will it benefit from using three wires in an old home installation?
Enough of this wondering.

60jarek wrote:

People buy the cheapest crap, and then they are surprised at the end result. You can count for yourself what happens by the difference of a few ohms in the installation - I have given my attention what to pay attention to when buying or choosing a cable.

60jarek wrote:

In our society, when choosing a cable, only the cable cross-section is taken into account, and whether for plastering or outside, the rest of the things are neglected.
"They buy the wrong cable - surprised that he often blows out the fuses and heats up - so they advise him to use a thicker cable - the effect is that the installation is even worse. And it was enough to buy a cable with the appropriate parameters and enjoy the effect of our installation for years"

So far, the problem has not occurred in "power" cables, although crap coaxial / antenna cables were common.
Maybe that is why the problem does not occur that people do not buy a cable, but call an electrician and he is responsible for choosing such a cable that everything works as it should - consumer incompetence spoils every market, makes it easier to cheat, but when consumers are professionals, it is difficult to crap.
Probably that's why it's easy to buy an extension cord with a cheated cross-section, and I haven't seen the cheated 100m disc yet.

60jarek wrote:

I do not get into discussions about the alloys and the composition of alloys for the production of the conductor.

What I wrote about is quite important from the point of view of the profitability of cheating, if it is difficult to gain advantage, the probability of fraud will be lower.

The topic is from over a decade ago, so the author solved a long time ago and forgot about that problem.
It would make sense to add something if it added something to the topic.
I am sorry to say that your entry does not bring anything useful, it is just arousing fear, so far unsupported. In every area you can frighten with poor quality, but there are also areas where you can take the first better product from the shelf and it will be good, I don't buy cables very often, so I cannot assess the market in 100%, but until recently it was the case with cables.
If someone breaks the fuses and the cable heats up, it should stop damaging the craft and call an electrician, no miraculous cable will solve the problem.

If you want to ask electricians if the problem of poor cable resistance exists, not in some old random topic, but create a new topic in the section where electricians often write.

60jarek wrote:

("So the content of copper in copper ha ha").
I am just browsing Allegro wire auctions and so far they have provided this parameter only in one auction. But there are wonderful other parameters given, and what beautiful descriptions: quality cables.

These your conclusions are from the "cloud".
Measure the cables and you will find out.

jarek_lnx wrote:

I am sorry to say that your entry does not bring anything useful, it is just arousing fear, so far unsupported.

Exactly.
Ps. It will not measure 60 cable jacks because it cannot and has nothing.

CYRUS2 wrote:

Write about yourself and draw conclusions.

CYRUS2 wrote:

These your conclusions are from the "cloud".
Measure the cables and you will find out.

A few years ago I had the opportunity to measure such cables - the manufacturer accepted the complaint, he could not believe what he produced.
Wherever I worked, this was done before accepting a batch of orders into the warehouse.
The manufacturer only asked to include in the order a request for a free test of the ordered cables.
There was already this topic on the electrode years ago, there were photos, etc.
The cloud will be blown away by a sign on the cable from the supermarket - it's a pity that I didn't keep the photos. (Leroy Merlin).
Take a walk around the shops and check what they are selling to people (even the producer doesn't have anything - they literally don't put anything there) - most of you have reliable suppliers and you won't buy anywhere, although cheaper. Ask for the cable data, I have to enter it in the documentation, there are no jokes and mockery about the topic.
Handwriting scholars, I think they will always be found.
I have nothing more to give in the topic - I have posted my comments and enough foam beating with the moderator pozamiata.