AEP Blueprint Reading & Interpretation 2 — Questions and Answers
Question 1: On an electrical single-line diagram, what does a circle with an 'X' inside typically represent?
- A transformer
- A fuse or fusible device (Correct answer)
- A motor
- A ground connection
Correct answer: A fuse or fusible device
A circle with an 'X' inside is the standard symbol for a fuse or fusible element on electrical single-line diagrams.
Question 2: In a P&ID (Piping and Instrumentation Diagram), what does the acronym 'PSV' stand for?
- Power Switching Valve
- Pressure Safety Valve (Correct answer)
- Pilot Signal Valve
- Phase Synchronization Valve
Correct answer: Pressure Safety Valve
PSV stands for Pressure Safety Valve, a critical safety device that automatically releases pressure when it exceeds a set point.
Question 3: What does a dashed line between two components on an electrical schematic typically indicate?
- A high-voltage connection
- A future or optional connection
- A mechanical linkage or enclosed unit boundary (Correct answer)
- A grounded conductor
Correct answer: A mechanical linkage or enclosed unit boundary
Dashed lines on electrical schematics typically represent a mechanical linkage between components or the boundary of an enclosed equipment package.
Question 4: On a utility distribution blueprint, a conductor shown with three short diagonal tick marks indicates:
- A three-phase conductor (Correct answer)
- A neutral conductor
- A three-wire conductor bundle
- A third harmonic filter
Correct answer: A three-phase conductor
Three diagonal tick marks (slash marks) across a conductor line indicate a three-phase circuit on electrical distribution drawings.
Question 5: Which view in a blueprint set shows the building or structure as seen from directly above?
- Elevation view
- Section view
- Plan view (Correct answer)
- Detail view
Correct answer: Plan view
A plan view (also called a floor plan) is a top-down orthographic projection showing the layout as seen from directly above.
Question 6: On a substation grounding grid plan, what does the symbol 'GRD' or a downward-pointing triangle typically represent?
- A grade elevation marker
- An earth ground connection (Correct answer)
- A gravel bed area
- A gradient slope indicator
Correct answer: An earth ground connection
GRD or a downward-pointing triangle symbol indicates an earth ground connection, critical for safety in substation designs.
Question 7: What is the purpose of a 'title block' found in the corner of an engineering blueprint?
- To list all materials needed
- To show the electrical load schedule
- To provide drawing identification, revision history, and approval signatures (Correct answer)
- To display the legend for all symbols used
Correct answer: To provide drawing identification, revision history, and approval signatures
The title block contains critical administrative information including drawing number, revision level, project name, scale, dates, and approval signatures.
AEP Blueprint Reading & Interpretation 2
On an electrical single-line diagram, what does a circle with an 'X' inside typically represent?