European Equivalent to AWG

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fifty60

Senior Member
Location
USA
Is anyone familiar with the European equivalent to AWG for wire gauge? Is there an official document somewhere that converts between the 2 units?

I know it is all done in metric units. But how would I indicate #10AWG? Do I say I need 2.59mm wire?

Also, would system of calculating fuse size also work for the European market? Is there a different way to calculate fuses in Europe?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
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retired electrician
Is anyone familiar with the European equivalent to AWG for wire gauge? Is there an official document somewhere that converts between the 2 units?

I know it is all done in metric units. But how would I indicate #10AWG? Do I say I need 2.59mm wire?

Also, would system of calculating fuse size also work for the European market? Is there a different way to calculate fuses in Europe?
I think they use mm? for their standard wire sizes. 6 would be the standard size that is not smaller than a #10. It would have a cm area of 10,380 and 6mm? has a cm area of 11,800.
Here is a table from a wire manufacturer
 

fifty60

Senior Member
Location
USA
I currently rate all of my wires at 75 C based off of NEC Table 310-16. I would like to find the equivalents at 75 C in mm^2.
 

JDBrown

Senior Member
Location
California
Occupation
Electrical Engineer
I don't have a copy of the IEC, but from my quick Google searching it looks like there may not be an IEC equivalent to Table 310.16. You could try a tool like Cablesizer, though.
 

fifty60

Senior Member
Location
USA
A nice and useful looking tool. Is that the normal procedure for sizing conductors in Europe?

I would prefer to size to my fuse. I know there are more intricacies than that sizing from the NEC, but it does basically break down to being that simple. Wire based off of fuse size.

Is that not the case for Europe (IEC standards?)
 

Besoeker

Senior Member
Location
UK
Is anyone familiar with the European equivalent to AWG for wire gauge? Is there an official document somewhere that converts between the 2 units?

I know it is all done in metric units. But how would I indicate #10AWG? Do I say I need 2.59mm wire?

Also, would system of calculating fuse size also work for the European market? Is there a different way to calculate fuses in Europe?

OK.
Standard conductor sizes are given by the actual cross sectional area of the conductor. So 1mm^2 is physically 1mm^2.
We don't often use anything below 1mm^2 in what we do.
So 1, 1.5, 2.5. 4. 6, 10. 16, 25, 35, 50, 70, 90, 120, 150, 185, 240, 300.
Beyond that we, my operation, tend to parallel conductors for ease of handling.
 

fifty60

Senior Member
Location
USA
Thanks everyone, that helps a lot. So the standard sizing does break out into set increments (1, 1.5, 2, 2.5) and nothing in between?

I would still like to find a nice plain table that converts table 310-16 into metric, particularly the 75 C rated insulation at 30 C ambient. Or just the European equivalent table to 310-16....

I know there is not a clean conversion from one unit to the other, so I believe the best would be to always round up. For example if 8AWG is 8.37mm^2 then round up to 10mm. I would really just like a table of conversions to include with my equipment manual.
 

fifty60

Senior Member
Location
USA
Does anyone see a problem with using a table, such as this http://www.engineeringtoolbox.com/awg-wire-gauge-d_731.html and then rounding up to the next standard size?

This creates a real nightmare for sizing terminals etc...are the inbetween sizes (like 13.29^2 mm for 6AWG) available or do I have to round up to 16AWG? Would it be more helpful to use the 13.29mm^2 number or would the person in the EU have to get a 16mm^2?

Most convienient for me would be to just have a table with the exact conversion (13.29mm^2 for #6AWG) in a table.

Is it a common problem to find requirements for AWG and then have to convert?

This chart rounds up the metric mm^2 to standard sizes http://www.penn-union.com/ref material/AWG vs. Metric Wire Size Chart.pdf
 
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fifty60

Senior Member
Location
USA
The main problem is with sizing conductors for permanently connected equipment. Everything in the equipment is built with AWG wire, so it will just have to be converted to whatever exact mm^2 conversion. If it is 12.8378mm^2, then that is what it is because that is what is in the equipment. But for equipment that is permanetly connected via customer supplied conductors to mains, i'm concerned with how to specify that wire.

My initial thoughts here are to, for example, for equipment that needs #8AWG wire to take the metric equivalent 8.36mm^2 and round up to a standard size 10mm^2. Or would it be acceptable to specify 8.36mm^2 wire?
 

Besoeker

Senior Member
Location
UK
Thanks everyone, that helps a lot. So the standard sizing does break out into set increments (1, 1.5, 2, 2.5) and nothing in between?
Correct. Except we can buy AWG sizes too.

I would still like to find a nice plain table that converts table 310-16 into metric, particularly the 75 C rated insulation at 30 C ambient.
That's two different questions.
There are conversion tables for physical size of the conductors from AWG to metric and vice versa. That's the simple bit.
Current rating, what you guys call ampacity, is a whole different ball game. Variables such as installation method (BS7671 lists 20) single core, multi-core, armoured, non-armoured, insulation material, corrections for ambient.....etc.
There is no simple equivalence conversion for that. At least not that I'm aware of.
 
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Julius Right

Senior Member
Occupation
Electrical Engineer Power Station Physical Design Retired
Conductor cross sectional area [awg and MCM=kcmil] is defined in UL 1581/2003 Conductor dimensions [cross sectional area in cmil and mm^2] including diameter in inches and mm from 56 awg up to 2000 kcmil. Table 20.1 for solid conductor Table 20.2 for compact stranded, Table 20.3 for compressed concentric-lay-stranded and Table 20.4 for class B concentric-lay-stranded.
This standard contains also required tests and D.C. resistance at 20 and 25 dgr.C.
Conductor [for insulated cable] in sqr.mm it is defined in IEC60228 for solid, stranded [class2], flexible [class 5 and 6]-including diameter and resistance at 20 dgr.C.
 

fifty60

Senior Member
Location
USA
What I am wanting to do is point out to the installer is that the calculations for the wire size was performed considering 75 C Copper wire in ambient conditions of 30 C. I would then like to directly convert the AWG I get into mm^2. I would then round up to the nearest mm^2 size for the conductors the customer is expected to provide, ie the 3 phases and a ground for the permanent connection to main. I will then size my input terminals to cover this rounded up figure.

Does this not seem like a correct procedure? Also, what is the general term for mm^2. We shorten AWG to just "gauge". Do Europeans say "mm^2" every time they reference cable size?
 

PetrosA

Senior Member
Fifty60, I think what Besoeker et al. are getting at is that outside the US, there are no tables governing ampacity of conductors like what we have in the NEC. It's up to the electrician doing the installation to calculate what size conductor will be needed based on the load and installation specifics. Insulation is made of PVC (mostly) which also has a different temperature rating than the THHN type conductors we'd normally calculate for, plus a much higher conductor temperature is acceptable than what we consider OK. What you're calculating you need a #8 for, I would bet will get installed with a 2.5mm or 4mm cable based on the installing electricians calculations which he or she will base on the load you calculate for your equipment.
 

kwired

Electron manager
Location
NE Nebraska
Fifty60, I think what Besoeker et al. are getting at is that outside the US, there are no tables governing ampacity of conductors like what we have in the NEC. It's up to the electrician doing the installation to calculate what size conductor will be needed based on the load and installation specifics. Insulation is made of PVC (mostly) which also has a different temperature rating than the THHN type conductors we'd normally calculate for, plus a much higher conductor temperature is acceptable than what we consider OK. What you're calculating you need a #8 for, I would bet will get installed with a 2.5mm or 4mm cable based on the installing electricians calculations which he or she will base on the load you calculate for your equipment.
THNN is mostly PVC based, as well as other types with the "T" in the name. There are other types, most for more specific applications, but most of the general purpose types are PVC based. Same is probably true for EU installations.
 

Besoeker

Senior Member
Location
UK
What I am wanting to do is point out to the installer is that the calculations for the wire size was performed considering 75 C Copper wire in ambient conditions of 30 C. I would then like to directly convert the AWG I get into mm^2. I would then round up to the nearest mm^2 size for the conductors the customer is expected to provide, ie the 3 phases and a ground for the permanent connection to main. I will then size my input terminals to cover this rounded up figure.

Does this not seem like a correct procedure?
Well, you'd get a safe answer that way. But it might overkill. Suppose you determined that your requirement can me met with 0 AWG, the equivalent size would be 53.5mm2. Rounding it up to the nearest size would get you 70mm2 which is quite a lot more expensive than 50mm2. But what if you were using 0 AWG because the next size down didn't give you quite current rating you required? Maybe you would then running the 0 AWG ant significantly below its rating so that the 50mm2 would do.

Also, what is the general term for mm^2. We shorten AWG to just "gauge". Do Europeans say "mm^2" every time they reference cable size?
I don't know what other Europeans say (the Germans probably have a ten syllable word for it!) but we often omit it altogether. Our workshop foreman might ask our buyer 10 reels of black 1.5 for example. The context and buying habits make it clear what's required.
 

kwired

Electron manager
Location
NE Nebraska
Well, you'd get a safe answer that way. But it might overkill. Suppose you determined that your requirement can me met with 0 AWG, the equivalent size would be 53.5mm2. Rounding it up to the nearest size would get you 70mm2 which is quite a lot more expensive than 50mm2. But what if you were using 0 AWG because the next size down didn't give you quite current rating you required? Maybe you would then running the 0 AWG ant significantly below its rating so that the 50mm2 would do.


I don't know what other Europeans say (the Germans probably have a ten syllable word for it!) but we often omit it altogether. Our workshop foreman might ask our buyer 10 reels of black 1.5 for example. The context and buying habits make it clear what's required.
Same here. You want #2 American Wire Gauge you just tell the guy at the supply house you need some number 2, and maybe qualify it with what type such as THWN, XHHW, USE, bare ... copper, aluminum, stranded, solid....
 

Besoeker

Senior Member
Location
UK
Fifty60, I think what Besoeker et al. are getting at is that outside the US, there are no tables governing ampacity of conductors like what we have in the NEC.
Actually there are are lots of tables in BS7671. In fact the section on current ratings for conductors is is over 60 pages long. Different installation methods, different numbers of conductors, temperature correction factors, DC, AC type of overcurrent protection etc.......very detailed stuff.
 

fifty60

Senior Member
Location
USA
wire.jpg

Here is the conversion table found in IEC 60204-1. The main idea behind including a chart is so that the equipment is installed correctly and safely.

If I convert #8AWG into 8.37mm^2, and indicate that this calculation is for FEPW, RH, RHW, THHW, THW, THWN, XHHW, USE, and ZW insulation types, with a rating of 75 C at 30 C ambient, would that be helpful? Would it be accurate and a correct?

I would basically be wording my calculation of the metric size the same way that NEC table 310-16 is worded. I suppose if I were expecting the customer to supply the cable, I could jump to the next higher size (10mm^2) and list all of the requirements from NEC table 310-16, and provide terminals for 10mm^2.

For conductors I supply, I would just convert them directly to the non-standard size mm^2 size since that is what they are, or just provide the table in the manual for everything except the customer supplied wiring.

Perhaps the best way to go would be to supply the first three columns (standard size mm^2, AWG, actual mm^2) and then explain the conditions that the AWG was calculated (the conditions of NEC table 310-16)....
 
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kwired

Electron manager
Location
NE Nebraska
View attachment 9450

Here is the conversion table found in IEC 60204-1. The main idea behind including a chart is so that the equipment is installed correctly and safely.

If I convert #8AWG into 8.37mm^2, and indicate that this calculation is for FEPW, RH, RHW, THHW, THW, THWN, XHHW, USE, and ZW insulation types, with a rating of 75 C at 30 C ambient, would that be helpful? Would it be accurate and a correct?

I would basically be wording my calculation of the metric size the same way that NEC table 310-16 is worded. I suppose if I were expecting the customer to supply the cable, I could jump to the next higher size (10mm^2) and list all of the requirements from NEC table 310-16, and provide terminals for 10mm^2.

For conductors I supply, I would just convert them directly to the non-standard size mm^2 size since that is what they are, or just provide the table in the manual for everything except the customer supplied wiring.

Perhaps the best way to go would be to supply the first three columns (standard size mm^2, AWG, actual mm^2) and then explain the conditions that the AWG was calculated (the conditions of NEC table 310-16)....
If you are trying to specify a supply conductor size for this equipment why not just specify a minimum ampacity instead of a specific size? Not sure but I get the feeling that is what you are trying to do here.
 
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