CEA Reading Electrical Blueprints Questions and Answers

Question 1

An apprentice is reviewing a set of electrical blueprints for a commercial building and needs to find detailed information about the circuit breaker sizes, the loads served by each circuit, and the total connected load for Panel 'LP-1'.
In which part of the blueprints would this information most likely be found?

Accepted Answer

The Panelboard Schedule

Answer

The Symbol Legend

Answer

The Site Plan

Answer

The General Notes

Question 2

While looking at an electrical floor plan, an apprentice sees a symbol consisting of a circle with two short, parallel lines drawn through it, located on a wall. What does this standard symbol typically represent?

Accepted Answer

A duplex receptacle

Answer

A lighting outlet

Answer

A smoke detector

Answer

A single-pole switch

Question 3

An apprentice is tasked with determining the required length of a home run from a receptacle to the panel as shown on a floor plan. The plan has a noted scale of 1/4" = 1'-0". If the apprentice measures the distance on the paper to be 7.5 inches, what is the actual horizontal distance of the run?

Accepted Answer

30 feet

Answer

15 feet

Answer

22.5 feet

Answer

37.5 feet

Question 4

On an electrical drawing set, which document provides a simplified overview of the power distribution system, showing the path of power from the utility service to panelboards and major equipment, without showing the physical location of the components?

Accepted Answer

A One-Line Diagram

Answer

A Floor Plan

Answer

An Elevation Drawing

Answer

A Lighting Fixture Schedule

Question 5

During an installation, an apprentice notes that the electrical drawings call for Type NM cable for a circuit, but the project's written specifications explicitly require that the same circuit be installed in EMT conduit. In a case of conflict between the drawings and the specifications, which document is generally considered to take precedence?

Accepted Answer

The written specifications, as they provide detailed requirements.

Answer

The electrical drawings, as they are the primary visual guide.

Answer

Whichever method is less expensive to install.

Answer

The apprentice should request clarification via an RFI.

Question 6

Which of the following pieces of information is most likely to be found on an electrical site plan rather than on a building's floor plan?

Accepted Answer

The routing of underground feeders from the utility transformer to the building.

Answer

The location of wall-mounted duplex receptacles in the offices.

Answer

The mounting height of a fire alarm horn/strobe in a corridor.

Answer

The circuit number for the breakroom lighting.