A diamond symbol with PL indicates which device?

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

Answer: (A)

The diamond-shaped symbol with PL is signaling a control device that has a pilot indicator. PL stands for pilot light, an indicator lamp that shows when the circuit is energized. The diamond shape here represents a switch used in control circuits, and the note that the pilot light is separate means the indicator lamp is not built into the switch itself but wired as a separate indicator device. So the combination describes a low-voltage switch that includes a separate pilot light to show the switch is now energized.

A low-voltage transformer would be drawn with a transformer symbol, not a switch with a pilot indicator. A pilot light only would typically be shown as just the lamp indicator without the switch element. A high-voltage switch would use different symbols appropriate for high-voltage equipment and wouldn’t inherently imply a separate pilot light.