Electrical Wire Conversion Help Please

[Kenomac]

I need to purchase some 10ga electrical wire to install two water pumps going to the watermaker. So I cycled down to the hardware store here in italy, only to discover Europe uses an entirely different system to measure wire thickness. I tried to figure it out online while in the store, but it was like trying to read Chinese.

I'd greatly appreciate if someone can tell me what to buy. I need two conductor Standed (not solid) type 10ga wire. Three conductor will also be ok.

I took a picture of some that looked close. The wire needs to be able to handle a 20amp breaker/load.

Thanks

Ken

[socaldmax]

Diameter in millimeters: 2.5882 mm

Cross sectional area in square millimeters: 5.2612 mm2

[bikesherpa]

FROR = type of cable (PVC, for indoor or outdoor use)
3G2,50 = 3 conductors, 2.5 square millimeters area section each conductor (ca. AWG 13)
for 20 amps, i would go the next size up, i.e. 3x4 sq.mm depending on cable length

[Terra Nova]

Don't shop for marine grade cable at a hardware store.

[mrm]

Originally Posted by Kenomac

[...]only to discover Europe uses an entirely different system to measure wire thickness. I tried to figure it out online while in the store, but it was like trying to read Chinese.

Don't worry, I get the same when trying to get a grip on AWG
Anyway, Europe is SI-unit centric and wires are specified by their cross section area, given in millimeters squared. Typically electrical code will specify 1.5mm2 for 10A circuits, 2.5mm2 for 16A circuits and 4mm2 for 20A and 25A circuits, although these are only generic guidelines and may be modified (derated) for atypical run lengths and environment temperature/cooling.

Perhaps this table will be useful:
https://en.wikipedia.org/wiki/Americ...AWG_wire_sizes

Standard wire sizes are:
0.75 mm2
1.0 mm2
1.5 mm2
2.5 mm2
4.0 mm2
6.0 mm2
10 mm2 and so on..

In your case, I would substitute 10ga with either 4.0 mm2 or 6.0 mm2, depending on run length and expected environment temperatures.

Edit: Look at the explanation of wire naming under harmonized european naming standard:
http://www.lapptannehill.com/wp-cont...e-Overview.pdf

For your application request something like H03VV-F or H05VV-F and specify number of conductors and their cross section area.

[Kenomac]

I'll take this information down to the marine store in the morning.

Thanks much.

[Lars_L]

If you want to calculate the cable dimension there are a simple way. You take the distance (one way) between to battery and the user equipment. (Yes, the current need to go both from the battery and back to it, so therefore the cable length is twice as long.) Measure it in meters. As compare you have almost 2 meters between your fingertips. (More exact you have the same length between your fingertips as you are long.) This distance you take times the current that flows in the cable. At last you divide the result by 10. Now you have the required cable area in square millimetres. This "calculation" assumes that its a 12 volt system and that you don't want more than 3% voltage drop.
One example. The are 3 meter between the battery and the equipment. The equipment takes 12 ampere. The calculation gives 3 (m) * 12 (A) / 10 = 3.6 mm² cable area.

This is not meant to be a argument for the metric system. For a discussion about the advantage of the metric system there is an old thread that's always accurate.

[k. michael marquardt]

Just a suggestion: You should install your pumps with marine grade tinned wire. The wiring found in a normal Italian hardware store will corrode within a couple of years and your pumps might stall then.

[nigelmercier]

Originally Posted by Kenomac

... only to discover Europe uses an entirely different system to measure wire thickness.

Nope, it's only you lot that still use an antiquated system

Good info in sizing here.

[exMaggieDrum]

Here is a handy table for wire sizes showing US AWG, Metric, and mm2 (squared). The cable you had the photo of looks to be about 14AWG. Looking at the table 6.0 is what you need to equate to 10AWG. Another poster indicated that as well.

[Reefmagnet]

Rule of thumb when all else fails is 10A per mm2 for up to 10m