Why is 1/2 inch pipe called that when nothing about it is 1/2 inch?

[K8MHZ]

What sounds better or easier to remember 3/8; 5/8; OR 1/2. The same in guns, would you rather say 429 caliber (actual size) gun/rifle OR 44 caliber ????????????:happyyes:

Next time you go to the SH ask for .50 caliber NM clamp type connectors. Tell them the .375 caliber connectors are too small, despite the fact they fit into the same hole. You know, like .38 spl's and .357's.

 

[jusme123]

One that fits.



The code requires the NM to be secured to the box. :thumbsup:

so I can't use a sleeve?

 

[kwired]

Where did 4160v 3ph4w come from? As I understand it a 2400v 1ph distribution system came first. May it be why was 4160v selected for a wye distribution system to increase the 2300v 1ph systems capacity with out the need to change the L-G voltage?
And what about 7200? Would it be 7200/1.73= 4160V nominal. And 12470/1.73=7200v nominal. And what about 13,200, and 13,800?

And why was 480v selected as basis for a LV dist sysem?

You could probably ask similar question about how 208V or 277V became standards.

I would guess 480 was chosen for the reason it is easier to make dual voltage 240/480 equipment than to make dual voltage equipment at a different ratio. 600 volts is a recognized standard voltage - but you don't really see it very often, and 600 volt equipment is likely more expensive because it is just not produced in the kind of quantities as 240/480 equipment.

PIPE is measureds as INSIDE dia........


TUBEING is measures as OUTSIDE dia.............

A 2" Tubeing should fit inside a 2" pipe

But with varying wall thickness sometimes you can not depend on how tight that fit may be.