Metric Wire

[bigsid]

I Think Electricians Should Be Taught How To Convert Metric Wire To Kcmil In These Ibew Classes Because Being In The Navy Seabees And Working Overseas Alot I've Seen Some Electricians Other Organizations That Wasn't Familiar With The Metric System Or How To Convert It For The Proper Amperage Size.

 

[eric stromberg]

I Think Electricians Should Be Taught How To Convert Metric Wire To Kcmil In These Ibew Classes Because Being In The Navy Seabees And Working Overseas Alot I've Seen Some Electricians Other Organizations That Wasn't Familiar With The Metric System Or How To Convert It For The Proper Amperage Size.

For a straight conversion, 1sqmm = 1.97 kcmil

That having been said, amperages for conductors are a regional issue. You'll have to check with the proper standards for whatever country you are in.

 

[LawnGuyLandSparky]

When determining just what to include and what to leave out of a training program, one would have to justify using valuable class time on an issue that affects less than 1% of the members of a trade. All you'd need is a wallet-sized conversion table.

 

[charlie b]

When determining just what to include and what to leave out of a training program, one would have to justify using valuable class time on an issue that affects less than 1% of the members of a trade.

That I agree with.

All you'd need is a wallet-sized conversion table.

No, it?s not that simple. My company is working on a large project for a foreign country that uses the metric system. There are three separate things to consider.

First, there is a simple unit conversion. You don?t even need to do the math, since this information is available in Table 8. For example, a #12 AWG conductor has an area, in metric units, of 3.31 mm2.

Secondly, knowing the metric equivalent area of an AWG size is to know nothing useful. Nobody overseas actually makes a wire with a metric area of 3.31 mm2. They make a 2.5, and they make a 4.0, but not a 3.31. So which do you use for a 20 amp circuit? The next larger, you say? Not so fast, say I.

Finally, different countries use different values for the max allowable temperature of the insulation system. For the project I mentioned earlier, we are told that wire is allowed to reach 105 degrees C. So how do you factor that into ampacity tables?

 

[Inspectorcliff]

Awg

Awg

Being an American, not that other countries don't have good ideals, I think I will stick with the American measuring system. If I should have to go back overseas then I'll do the old saying "In Rome do as the Romans do". But not yet.

 

[Binbinb]

For a full AWG metric conversion table you can look here Metric AWG Conversion Table.

The table has the standard metric sizes so in the above example you would be selecting 4mm2 (not 3.31).

In IEC type countries the common practice is to select the breaker than calculate the cable size (depending on current, voltage drop and possibly fault rating using various derating factors). There is a free IEC cable size calculator you can use to verify the sizes.

Hope this helps.