April 19, 2017

Colored Wire Insulation? Colored Jackets? Really?

A long time ago in the smallest state of the Union, a few people who were, and many still are, members of an organization called the New England Section of the International Municipal Signal Association, for short, NEIMSA. Marty Ballou and his team of I believe Bruce Rice, Ralph Mills, Norm Davies, Norm Bennett and maybe others, came up with the idea of identifying wiring conductors in a fire alarm system so that a troubleshooting technician could be more efficient in locating the cause of problems in a system. A short time thereafter, after much effort, the Rhode Island legislature, along with Governor Joe Garrahy, were convinced that this was a great idea and it became a requirement for future fire alarm system installations in the State. The color assignments then, and as they exist today, are as follows:

Circuit Function

Conductor Color

Initiation Circuit

Red +, Black -

Notification Appliance Circuit

Blue +, White -

Smoke Detector Power

Violet +, Brown -

Remote Annunciator

Violet & numbered

Door holder, low voltage

Gray, Gray

120VAC Door Holder

Black, white

Elevator Capture

Brown, Yellow


Orange, Yellow

Auxiliary Sound System Shutdown

Orange, Yellow

Master Box Trip Circuit

Orange, Orange

Local Smoke Alarm Interconnect



As you may imagine, the chart was for the color of the wiring conductors, maybe THHN type in raceways, as that is what most systems used with conventional zones and appliance circuits. Now with the advent of addressable and voice systems, many systems use multiple conductor cables under an overall jacket. A technician trouble shooting a system may want to follow a NAC circuit, for instance, through the building, and all he needs to know initially is the color of the outside jacket of the circuit he is chasing. The color of the insulation of the conductors inside the jacket only need to indicate the polarity of the circuit, if one exists.

On our projects, no matter where the project is located, we specify the following for the outside jacket colors:

Circuit Function

Jacket Color

SLC Data Loop


Style 7 Data Loop


RS 485 data loop (RA's,  Remote FCC's)


Visual Notification Appliance Circuit


Audio Notification Appliance Circuit


Door Holder Circuit, low voltage


Auxiliary Function


Firefighter Telephone


Conventional Zone


* With several auxiliary functions, and if their cables are run together, additional jacket colors may be needed to properly identify the circuits

* Where appliances are combinations of horn and strobe, jacket color shall be blue

When two auxiliary function control cables are run together for any distance, we add another color, i.e. damper and fan control.  However, most dampers and fans are controlled by a control or relay module in close proximity to the device being controlled and therefore a cable with one color is usually sufficient. If however, the fans and the dampers are controlled say from a transponder, an additional cable color would probably be used. Elevator control is another example where there might be three functions controlling the elevator but where a second or third cable color might not be required due to the proximity of the equipment being controlled. The control or relay modules are usually installed near the elevator controller with short cable runs and identification information on each module.

There are more and more companies that offer a wide selection of jacket colors without requiring one to purchase large quantities of a color. The more specifiers who use a jacket coloring scheme, the more manufacturers we will have that will stock multiple colors. We are, however, flexible on the colors if a particular color is not available at a reasonable price.

In all cases, we require that a placard be installed inside each FACP, fire command center, transponder and NAC power supply as well as on the as-built drawings identifying the color of each cable.

When we’re asked what color we want for the conductor insulation in a multi conductor cable, we ask for red and black unless that requires a custom run, then we just ask for two colors, and hopefully one will be white for the negative conductor, when circuit polarity exists.

Questions, comments? Just give me a call or shoot me a note.

Bob Hill,
Robert Hill & Associates, LLC
110 Haverhill Road, Suite 376
Amesbury, MA 01913