Distribution box indicator light color

Indicator light colors in distribution boxes communicate system status: red for faults, green for normal operation, yellow for warnings, and blue/purple for communication.

Standard Color Meanings

Red: Indicates a fault or alarm. A steady red light signals a major fault such as a short circuit or overload, while a blinking red light indicates a minor fault like a loose connection or minor issue that requires attention. Green: Represents normal operation.

A steady green light shows stable power, while a slow blinking green may indicate standby mode.

Yellow/

Amber: Serves as a warning. A steady yellow light often indicates low voltage, and a blinking yellow light signals a temporary abnormal condition or voltage fluctuation that may need inspection.

Blue/

Purple: Used for communication status. A steady blue or purple light indicates a normal connection, blinking shows active data transmission, and no light signals a communication failure. Steady vs.

Blinking Lights

Steady lights generally indicate a stable condition, whether normal (green) or abnormal (red/yellow). Blinking lights often indicate a temporary or minor issue, such as a minor fault, standby mode, or ongoing data transmission.

Industry Variations

While the above is a common standard, some industries may have variations: In motor control centers (MCCs), red may indicate "motor off" and green "motor running," whereas in process control equipment, red often signals a fault and green indicates normal operation.

IE

C 60204-1 standards recommend using red for STOP/OFF actuators, green for START/ON actuators, and blue for RESET functions, with white, grey, or black as neutral or alternate colors.

Practical Tips

Always check the label on the distribution box first, as manufacturers may provide specific color coding. Use indicator lights as a quick diagnostic tool to identify faults, warnings, or communication issues without opening the panel. For safety, ensure power is off before performing any maintenance on the indicator lights.

Understanding these color codes helps operators quickly assess the status of electrical systems, respond to faults, and maintain safe operation.