If you grew up in Am
erica, meters and millimeters are basically a foreign language. When I used to read a ruler growing up, I didn’t bother using the centimeter side. Actually, I didn’t even know why it was there. Thinking about it, the one on my desk now doesn’t even have centimeters (I should probably fix that). However, if you grew up on the other side of the pond (or anywhere else for that matter), the metric system is alive and well.
Well with International and North American wire size, it can be just as confusing. For North America, I never understood why as the wire got larger, the number got smaller. Why is 18 AWG smaller than a 10 AWG? Well, back in the day the gauge was determined by how many times the wire had to pass through the drawing dies. The smaller wire, such as 18 AWG, is going to have to pass through more times than the 10 AWG. Actually, makes sense, right?
When you start going back to wire gauge and millimeter size it gets even crazier! But what do those numbers really mean? The numbers (1.0mm², etc.) refer to the actual dimension of the single, solid, round conductor. Stranded wire is determined by the total cross-sectional area of the conductor. That also determines its current carrying capacity. When you include the insulation and jacket, it’s called the overall diameter.
UL Stepping In to Help
So with all of that, UL thought it might be helpful to fix some things. The new update for the UL 62 regulation requires that cross-sectional ratings of North American wire gauges meet the minimum standard for International wire types. This is only necessary with hybrid/universal cords, such as our 3500 series that has UL, CUL, and VDE approvals.
American vs International & UL Amp Rating vs International Amp Rating
|
American Wire Gauge |
International Size (mm²) |
UL Amp Rating |
International Amp Rating |
|
17 |
1.0 |
10A |
10A |
|
16 |
1.0 |
13A |
10A |
|
15 |
1.5 |
15A |
15A |
On the old UL, 62 1.0mm² was slightly larger than its 18 gauge equivalent, so the new UL 62 update made it be compared to a 17 gauge. 15 gauge is about 1.5mm², so they are both rated at 15 amps. UL wanted to make it easier for project managers and consumers working across the globe.
If you have any questions regarding this, our amazing sales team is here to help you. So please don’t be scared next time you see “mm²”.
By Clark Cable
PS. My boss is from Europe and thinks inches is hilarious…