Wire markers and cable markers are used to label wires and cables. Wire marking can be done before or after termination. There is a large variety of markers available, including an array of sizes, colors, and lengths. When selecting individual products, specifications to consider include materials of construction and certifications or approvals.

Types

Selecting wire markers and cable markers requires an understanding of product types. Product categories include dot matrix labels and dot matrix ribbons, laser labels and laser sheets, pre-printed markers, and self-laminating labels. Wire markers and cable markers also include thermal transfer labels, thermal transfer ribbons, tags, and wire wraps.

Dot matrix labels and dot matrix ribbons are designed specifically for use with dot matrix printers. Similarly, laser labels and label sheets are designed for laser printers.

Self-laminating labels include a clear portion that will wrap around and laminate the legend. This protects the printed area of a label from exposure to solvents, oil, water, or other contaminants.

Thermal printers require thermal transfer labels or thermal transfer ribbons. Wire markers and cable markers also include tags and wraps.

Heat shrink tubing is available in a wide range of sizes, colors, and materials to suit many different applications.

Wire wraps are labels with a printable side and an adhesive side used to wrap and stick the label to the tube or wire. Specialty wire markers and cable markers are also available. When the marker wraps around the wire the legend is visible from all sides.

Wire wrap labels. Image Credit: Duralabel

Sleeve markers should only be used before a termination because they must be slipped over the open end of the wire. They provide a degree of flexibility before they are heat-shrunk around the wires or cables. They are non-adhesive and once they are shrunk, sleeve markers provide permanent identification that can withstand harsh environments.

Pre-printed markers can be purchased in a variety of stock legends. Generally, custom legends can also be selected. They are ideal for many applications. 

Printable markers offer the flexibility of labeling as needed, and may provide a better option when a long legend with multiple characters is required.

Printable marker. Image Credit: hr.s. Hughes

Wire ties- Ties are used to bundle wires, cables, and tubing together. Wire tie markers have space available for placing an identifying mark.

Identification cable ties. Image Credit: Cable Markers Company Inc.

Specifications

Typically, wire markers and cable markers are made of cloth, nylon, polyester, metalized polyester, steel, or vinyl. Some products are RoHS compliant. Others bear the UL Mark.

Diameter- The size of the wires and cables determines the diameter of the marker. Similarly, the length of the label should be five times the outer diameter of the wire to be marked.

Environmental conditions- The environmental conditions, such as operating temperature, should be considered when selecting a wire marker and the material it's made from. 

Approvals and Certifications

Wire markers and cable markers differ in terms of approvals and certifications. Restriction of Hazardous Substances (RoHS) is a European Union (EU) directive that requires all manufacturers of electronic and electrical equipment sold in Europe to demonstrate that their products (including wire markers and cable markers) contain only minimal levels of the following hazardous substances: lead, mercury, cadmium, hexavalent chromium, and polybrominated biphenyl and polybrominated diphenyl ether. The UL Mark denotes that Underwriters Laboratories Inc. (UL) has found that samples of the product met UL's safety requirements. These requirements are based primarily on UL's published Standards for Safety. 

Resources

Electrical, Wire & Cable Identification

Image Credit:

R.S. Hughes