Electrical Labeling Requirements

We've all used them. Little books or rolls of numbers to label 
conductors that help keep our circuits traceable. Labeled correctly, 
both installations and troubleshooting are much easier.<br><br>Even 
rolls of colored tape serve as labeling. For example, when using large 
cables for high-amperage installations, all the power conductors usually
 have black insulation. So identifying a three-phase circuit can be done
 with color-coding. A 480-volt circuit is designated by brown, orange 
and yellow color-coding tape. Thomas & Betts

Steve Maurer, IME

We've all used them. Little books or rolls of numbers to label conductors that help keep our circuits traceable. Labeled correctly, both installations and troubleshooting are much easier.

Even rolls of colored tape serve as labeling. For example, when using large cables for high-amperage installations, all the power conductors usually have black insulation. So identifying a three-phase circuit can be done with color-coding. A 480-volt circuit is designated by brown, orange and yellow color-coding tape.

Specialty labels are often used for voltage and other information.

In larger, more complex facilities, the outside of the conduit is often labeled to help in tracing circuits in the plant.

However, electrical labeling goes beyond conductor and circuit identification. Changes to the 2014 NEC require more specialized labeling on the outside of many components. But many of these requirements were introduced as far back as the 2002 NEC. The purpose of this type of labeling is worker/installer protection. One of the main hazards addressed today is arc-flash.

Of course, OSHA also has requirements for equipment and system labeling. In the case of arc flash labeling, the employer or owner of the facility is responsible for ensuring equipment is labeled properly. Some typical equipment that must be labeled for arc flash are:
  • Switchboards
  • Panel boards
  • Industrial control panels
  • Meter socket enclosures
  • Motor control centers
Apart from arc flash warnings, many manufacturers and installers label equipment with necessary labeling. Since equipment installations cannot be inspected without them, pre-labeling speeds up the approval process. Often, these labels inform of type of equipment – such as main disconnects – and may include other device specifics.

But arc flash labeling will be an important part of OSHA inspections. Even if your equipment was grandfathered in before the most recent NEC regulations, OSHA will require correct labeling be affixed when any upgrades or modifications are done. Fortunately, label manufacturers have products and labeling machines to make it easier to label equipment and remain in compliance.


Photo courtesy of Thomas & Betts