Power indicator light color in the distribution box

Indicator lights in distribution boxes use color codes to show system status: green for normal, red for faults, yellow/amber for warnings, and blue/purple for communication.

Standard Color Meanings

Green Light: Indicates normal operation. A steady green light means stable power, while a slow blinking green may indicate standby mode or low activity. Red Light: Signals a fault or alarm.

A steady red light usually represents a major fault such as a short circuit or overload, while a blinking red indicates a minor fault like a loose connection that requires attention.

Yellow/

Amber Light: Represents warnings or transitional states. Steady yellow often indicates low voltage or a condition that requires caution, while blinking yellow signals temporary abnormalities or voltage fluctuations that may need inspection.

Blue/

Purple Light: Typically used for communication status. A steady blue/purple light shows a normal connection, blinking indicates data transmission, and no light suggests a communication failure.

Additional Notes

Phase Indicators: In three-phase systems, indicator lights may show the presence of each phase (L1, L2, L3). If a phase fails, the corresponding light goes off, helping identify phase loss or imbalance. Integration with Protection Devices: Lights are often connected to circuit breakers or relays.

They provide immediate visual feedback during overloads, short circuits, or ground faults, enabling faster troubleshooting and safer operation. Steady vs. Blinking: Steady lights generally indicate a stable condition, while blinking lights often signal a temporary or minor issue that requires monitoring or corrective action.

Understanding these color codes allows operators and technicians to quickly assess the status of a distribution system, identify potential problems, and maintain safe and efficient operation.