Safety warning signs for cable trays

Cable trays containing conductors over 600 volts must be marked with “DANGER — HIGH VOLTAGE — KEEP AWAY” at intervals not exceeding 10 feet, following NEC and ANSI standards.Required Markings

Cable trays that carry conductors rated over 600 volts are required to display DANGER warning labels stating “DANGER — HIGH VOLTAGE — KEEP AWAY” at intervals no greater than 10 feet along the tray . These labels must comply with NEC Section 110.21(B), which mandates that hazard signs use effective words, colors, and symbols to clearly communicate the danger . Handwritten labels are not permitted except for variable information, and the design should follow ANSI Z535.4-2011 guidelines for font, color, capitalization, and symbol usage .

Placement and Visibility

• Labels should be visible and legible to personnel who may access or work near the cable tray.
• In industrial settings, inaccessible trays may be exempt if only qualified personnel service them under controlled conditions .
• Warning signs should be placed at entry points, along the tray, and near junctions or bends where personnel may approach the cables .

Additional Safety Considerations

• Ensure proper cable management to prevent damage, short circuits, or insulation failure, which can increase the risk of electrical hazards .
• Maintain spacing and insulation between cables to reduce the risk of arcing or overheating .
• In hazardous locations, only cables permitted for classified areas should be installed, and warning signs should reflect the potential for arc-flash or electric shock .

Summary

To comply with safety standards and reduce risk, cable trays carrying high-voltage conductors must be clearly marked with DANGER labels at regular intervals, designed according to ANSI and NEC specifications, and placed where they are visible to personnel. Proper installation, spacing, and maintenance of cables further enhance safety and prevent electrical accidents .