The diamond symbol with PL stands for which device?

• A. Low-voltage transformer
• B. Pilot light only
• C. Low-voltage switch with a separate pilot light
• D. High-voltage switch

Answer: (C)

Understanding control symbols: a diamond shape with PL marks a switch that has an indicator light. The PL stands for Pilot Light, showing there is an indicator used to display the switch’s status. When the symbol also indicates that the pilot light is separate, it means the lamp is not built into the switch housing but wired as a separate indicator in the low-voltage control circuit. This combination is specifically a low-voltage switch with a separate pilot light, which is common in control panels where you want a visible status indicator without feeding the indicator from the main line voltage. A stand-alone pilot light would show only the lamp, without a switch element; a high-voltage switch would be drawn with different conventions and wouldn’t be labeled this way.