[RE-wrenches] useful info on wire color coding

[Marco Mangelsdorf]

But I'm still trying to determine if the black-red-blue and
brown-orange-yellow sequences are appropriate for clockwise or
counter-clockwise phase rotations.

 

marco

US, AC:The US National Electrical Code only mandates white (or grey) for the
neutral power conductor and bare copper, green, or green with yellow stripe
for the protective ground. In principle any other colors except these may be
used for the power conductors. Black, red, and blue are used for 208 VAC
three-phase; brown, orange and yellow are used for 480 VAC. Conductors
larger than #6 AWG are only available in black and are color taped at the
ends. 

US AC power circuit wiring color codes.


Function

label

Color, common

Color, alternative


Protective ground

PG

bare, green, or green-yellow 

green


Neutral

N

white

grey


Line, single phase

L

black or red (2nd hot)

 


Line, 3-phase

L1

black

brown


Line, 3-phase

L2

red

orange


Line, 3-phase

L3

blue

yellow

				

 

 
<http://upload.wikimedia.org/wikipedia/commons/c/cc/3_phase_AC_waveform.svg>
File:3 phase AC waveform.svg

US DC power: The US National Electrical Code (for both AC and DC) mandates
that the grounded neutral conductor of a power system be white or grey. The
protective ground must be bare, green or green-yellow striped. Hot (active)
wires may be any other colors except these. However, common practice (per
local electrical inspectors) is for the first hot (live or active) wire to
be black and the second hot to be red. The recommendations in Table
<http://www.allaboutcircuits.com/vol_5/chpt_2/2.html#wire5.tbl> below are by
Wiles.  <http://www.allaboutcircuits.com/vol_5/chpt_2/2.html#JWi.bibitem>
[JWi] He makes no recommendation for ungrounded power system colors. Usage
of the ungrounded system is discouraged for safety. However, red (+) and
black (-) follows the coloring of the grounded systems in the table. 

US recommended DC power circuit wiring color codes.


Function

label

Color


Protective ground

PG

bare, green, or green-yellow


 2-wire ungrounded DC Power System

 

 


Positive

L+

no recommendation (red)


Negative

L-

no recommendation (black)


 2-wire grounded DC Power System

 

 


Positive (of a negative grounded) circuit

L+

red


Negative (of a negative grounded) circuit

N

white


Positive (of a positive grounded) circuit

N

white


Negative (of a positive grounded) circuit

L-

black


 3-wire grounded DC Power System

 

 


Positive

L+

red


Mid-wire (center tap)

N

white


Negative

L-

black

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20100821/3d0478d5/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 47283 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20100821/3d0478d5/attachment-0005.png>