Most of our drawings are coming from the architects in metric up here now. In our 1998 code book our section on explosion-proof changed to something more inline with european equipment, so its almost becoming inevitable. When the big rush was on for the 1998 Calgary Olympics everything was metric try finding replacement parts for this stuff now.
Re: Metric or English?#18523 12/10/0209:00 PM12/10/0209:00 PM
I can't see any reason for using the other strange units. How do you answer a simple question like:
"What is the resistance of twenty feet of #14?"
"Oh, that's easy" you go "I'll just look it up in a table" and walk off to find that table.
Had it been in metric the only thing you need to know is the resistivity of copper (0.017 ohm mm2/m)
"What is the resistance of 6 m of 2.0 mm2?"
"Oh, that's easy", I go, "6 times 0.017 over 2.0 is roughly 0.05 ohms"
I'm an engineer and many of our books in class (here in Sweden) were American, using strange units like the British Thermal Unit. In my world heat is measured in Watts, without need for a special unit.
[This message has been edited by C-H (edited 12-11-2002).]
Re: Metric or English?#18526 12/11/0207:27 AM12/11/0207:27 AM
Doc, you wouldn't ask for 500', you'd ask for 166 m of #16. Or if metric units are seriously adopted you'd probably ask for 150 m of 16mm conduit. No. it just depends on what you're used to. I'll never ever get 'round to think in feet and inches, I always convert. However, I think metric is more logical and it's according to the decimal system. i guess here in Austria 200 years ago here in Austria no one thought of metric units. Nowadays the only things that still come in inches are plumbing pipes and sometimes lumber. It's not official, but in every shop you still buy 3/4" gas pipe or 1/2" garden hose. But elsewhere? Wires are 0.75, 1, 1.5, 2.5, 4, 6, 10 and more mm2, conduit (PVC only here) is 16, 20, 25, 30, 40, 50 and more mm. Guess if America should ever adopt metric cable sizes, the typical 15A circuit would be wired with 2.5 mm2.