Reference & Information

Wire Color Coding

This page describes copper wire color coding as defined by current military specifications. The color coding is used on the wiring insulation.
Wire color coding is used to indicate wire function or the voltages the wire carries.
The National Electrical Code [NEC] requires their own coding system for premises wiring.
The National Fire Protection Association [NFPA]; specifies wire insulation colors for industrial machinery [machine tools].
These color codes may or may not apply to your specific application, because they apply to Drills, Motors, and so on.
The NFPA color scheme uses a solid color with another color strip for a number of applications.
NFPA color codes differ from NEC and Mil standard wire codes. For details, see: NFPA 79: Electrical Standard for Industrial Machinery.
Fiber insulation is listed on the Fiber Insulation Color Code page.
PCIe Graphics Card Power Color Codes [External PCIe Connector].

Colors for chassis and interconnecting wiring system by function
Wire Function Base Color Identification # Alternate color code Identification #
Grounds, Grounded elements Green 5 Green 5
Heaters or filaments Brown 1 White/brown 91
Power Supply B+ Red 2 White/red 92
Screen Grids Clock Orange 3 White/orange 93
Transistor Emitters Yellow 4 White/yellow 94
Transistor Bases Black 0 White/black 90
Transistor Collectors Blue 6 White/blue 96
Power Supply, minus Violet 7 White/violet 97

The table above provides hook-up wire color coding for chassis and interconnecting wire with in an equipment chassis.
The color identification number is defined in the Military Standard, but not addressed on this page.

Wiring Colors for Interconnecting by Voltage
Voltage Wire Color Identification #
+151 to +500 Red 2
+61 to +150 White/Red 92
+26 to +60 White/Brown/Red 912
+7 to +25 White/Red/Orange 923
+2 to +6 White/Red/Yellow 924
-26 to -60 Violet 7
-11 to -25 White/Violet 97
-2 to -10 White/Violet/Yellow 47
Ground Green 5

The table above provides an alternate system for hook-up wire color coding for chassis and interconnecting cable with in a chassis.
The color identification number is defined in the Military Standard, but not addressed on this page.

Color Coding for AC Wiring
AC Service Phase A Phase B Phase C Neutral Ground
115v 60Hz 1 f Black --- --- White Green
208v 60Hz 3 f "Y" Black Red Orange or Blue White Green
230v 60Hz 3 f Delta Black Red Orange or Blue --- Green
115v 400Hz 3 f Delta Black Red Orange or Blue --- Green
208v 400Hz 3 f "Y" Black Red Orange or Blue White Green

The table above provides the Military standard for AC wiring Color Coding

Commercial Coding for AC Wiring
Service US Europe UK
115v/240v 60Hz Black Brown Brown
Common White Blue Blue
Ground Green Green/Yellow Green/Yellow

The table above provides one example of Commercial Coding for AC Wiring.
Refer to the National Electrical Code [NEC] to determine cable sizing for premises wiring, and wiring color coding requirements.
Refer to the National Fire Protection Association to determine cable sizing for industrial wiring, and wiring color coding requirements.
FYI: the NEC is part of the NFPA document.

Cable manufacturers will provide different current carrying numbers based on the insulation used for the wire.
The table below lists copper wire with a Teflon [TFE] insulation. Teflon insulation has a higher operation temperature range then other insulators, for example PVC. The table below is based on data derived from MIL-STD-975, using 700C as the operating temperature. To derate based on number of wires in a bundle:
IBW = ISW x (29 - #wire) / 28 @ [1 to 15 Bundled wires]
IBW = ISW x (0.5) @ [more then 15 Bundled wires]
ISW = Single wire
IBW = Bundled wires
To derate by temperature use; derate by 80% at 1500C, 70% at 1350C, or 50% at 1050C

Copper Wire TFE Insulated
AWG Size Current Carrying AWG Size Current Carrying
00 169 amps 0 147 amps
2 108 4 81
6 60 8 44
10 33 12 25
14 19 16 13
18 9.2 20 6.5
22 4.5 24 3.3
26 2.5 28 1.8
30 1.3 - -

I have seen one other Military Specification [MIL-STD-xx] for copper wire current capability. That standard [I did not note the standard number] listed AWG 18 [for example] as 10 amps with TFE insulation. That indicates that this additional military specification uses the same data listed in the table above, but may be listed for 250C, and not 700C as the table uses. So this table above has already been derated for 700C.

Listing for Wire and Cable Manufacturers, Cable Derating

Additional related technical data concerning Cable Design in Equipment Chassis

PC motherboard

Distributor rolodex Electronic Components Electronic Equipment EDA CDROM Software Engineering Standards, BOB card Cabled Computer Bus Electronic Engineering Design Table Conversion DB9-to-DB25.
DistributorsComponents Equipment Software Standards Buses Design Reference

Modified 1/21/12
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