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#67913 07/21/06 04:51 AM
Joined: Apr 2006
Posts: 233
K
Kenbo Offline OP
Member
Just looking at your posts here and often you mention wire gauge as 12/2 or 14/2 etc

Here in the UK we use cable like 2.5mm Twin&Earth (2.5T&E) or single cores 1.5mm.
Where the size stated is the diamiter of the copper core see here
How is cable sized where you are?


der Großvater
#67914 07/21/06 05:30 AM
Joined: Jan 2003
Posts: 4,391
I
Moderator
AWG or American Wire Gauge.

14 AWG is rated approx 20 amps

12 AWG is rated approx 25 amps


Bob Badger
Construction & Maintenance Electrician
Massachusetts
#67915 07/21/06 06:17 AM
Joined: Sep 2002
Posts: 1,498
Likes: 1
C
C-H Offline
Member
I've written a little on this, with some tables:
http://www.global-electron.com/wiresizes.htm

#67916 07/21/06 06:46 AM
Joined: Mar 2005
Posts: 1,213
S
Member
T&E looks very similar to NM cable.

Interesting- 2.5mm T&E cable is smaller than #12, yet allowed for 24A circuits, whereas the larger #12 NM is only approved to 20A?

#67917 07/21/06 10:24 AM
Joined: Apr 2004
Posts: 349
Member
I seem to remember hearing somewhere that metric amps are slightly smaller than non-metric, so that accounts for the difference in ampacity values.

kidding -
Radar


There are 10 types of people. Those who know binary, and those who don't.
#67918 07/21/06 12:42 PM
Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
Actually 12 ga is good for 25a (310.16)
240.4(D) reduces that to 20a because the "small conductors" are most likely to serve receptacles where the installer has no control over what the user will plug in. They will keep plugging things in until the breaker trips, then unplug the clock. 240.4(D) forces the 80% rule on the user.
Perhaps Europeans are more dilligent about load management.


Greg Fretwell
#67919 07/23/06 09:45 AM
Joined: Aug 2001
Posts: 7,520
P
Member
Quote
Here in the UK we use cable like 2.5mm Twin&Earth (2.5T&E) or single cores 1.5mm.
Where the size stated is the diamiter of the copper core

Not the diameter -- 1.0, 1.5, 2.5 etc. are the cross-sectional area of the conductor, in square millimeters.

The pre-metric cables (before 1970) use a size designation based on the strand diameter, e.g. 3/.036 is a conductor consisting of three strands, each of .036" diameter.

Here is a comparison of American 12/2 w/gnd Romex and British 2.5 sq. mm "T&E" cable:

[Linked Image]

[Linked Image]

[Linked Image]

Note that the ground conductor on the U.K. cable is a size smaller than the insulated conductors, 1.5 sq. mm on this 2.5 cable.

You'll note also that British T&E doesn't have any paper inside the outer sheath like Romex.


[This message has been edited by pauluk (edited 07-23-2006).]

#67920 07/23/06 11:13 AM
Joined: Mar 2005
Posts: 1,213
S
Member
OK, so it's more like UF! Is T&E rated for wet areas?

I'm going to have to pick up some samples of metric cable next time I'm over on that side of the pond...

[This message has been edited by SteveFehr (edited 07-23-2006).]

#67921 07/23/06 08:19 PM
Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
#14 is 2.08 mm2
@12 is 3.31 mm2

Per table 8


Greg Fretwell
#67922 07/25/06 03:11 AM
Joined: Apr 2006
Posts: 233
K
Kenbo Offline OP
Member
Thanks for the replys all I can say is I learned something new today.

Paul thanks for the correction. I got my vernier gauge out and measured the diameter of some T&E cores
1mm = 1.1mm
2.5mm = 1.7mm
6mm = 3.1mm
(20 years and still making asumptions tut tut)

C-H managed to follow "AWG" and "Metric" but just could not see the point of "Circular Mils" Who uses "kcmil" as a measument?


der Großvater
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