CSLB C-10 Electrical ContractorPlanning and EstimatingMedium
An electrical contractor is preparing a material takeoff for a new residential dwelling. The blueprints indicate a symbol consisting of a circle with a single vertical line extending upward from its top, and a single horizontal line passing through the center of the circle, with a short diagonal line on the left side of the horizontal line. What does this symbol represent?
- ASingle-pole switch
- BDuplex receptacle
- CCeiling-mounted light fixture
- DWall-mounted light fixture
Show answer & explanationAnswer & explanation
Correct answer: A. Single-pole switch
The described symbol (a circle with a vertical line extending from the top, and a horizontal line through the center with a short diagonal on the left) is the standard electrical blueprint symbol for a single-pole switch.
Why the other options are wrong
- B. A duplex receptacle is typically a circle with two parallel lines or two short perpendicular lines inside, or sometimes just two short parallel lines extending from the circle.
- C. A ceiling-mounted light fixture is usually a simple circle with two perpendicular lines inside, or a circle with a cross.
- D. A wall-mounted light fixture is often a half-circle or a circle with a line extending from its side, sometimes with a directional arrow.
Electrical Blueprint Symbols (Switches)
Standardized graphical representations used on electrical blueprints to denote the type and location of switches, crucial for planning and installation.
- Symbols are defined by industry standards (e.g., ANSI, IEEE, or local conventions).
- A single-pole switch (S) typically has a specific symbol to distinguish it from other switch types.
- Understanding these symbols is essential for accurate material takeoffs and installation.
Memory trick: Switches Start Simple, Get Complex