NCCER Module 26110-23PT 10

Electrical

Module 26110-23

Basic Electrical Construction Documents

Copyright © 2024 by NCCER, Alachua, FL 32615. Published by Pearson. All rights reserved.

1.0.0 Construction Drawings

Module 26110-23 – Basic Electrical Construction Documents

Objective

1. Explain how to interpret construction drawings.

a. Describe information found in drawing blocks.

b. Identify information found on different types of drawings.

c. Explain how to interpret drafting lines.

Module 26110-23 – Basic Electrical Construction Documents

Performance Tasks

There are no Performance Tasks associated with this section.

Module 26110-23 – Basic Electrical Construction Documents

1.0.0–1.1.0 Construction Drawings (1 of 2)

•

Each page in a set is called a sheet.

•

Drawing sheets include:
–

Site plan
–

Floor plan
–

Elevation drawing
–

Sectional view
–

Detail drawing(s)

Module 26110-23 – Basic Electrical Construction Documents

1.0.0–1.1.0 Construction Drawings (2 of 2)

•

Blocks are found on each drawing.

•

They include information such as:
–

Origin
–

Identification
–

Content
–

Use
–

Scale
–

Revision history

Module 26110-23 – Basic Electrical Construction Documents

1.1.1 Title Blocks

•

Title blocks contain important
information.

•

Be sure to check:
–

Scale
–

Current revision

Module 26110-23 – Basic Electrical Construction Documents

1.1.2 Sheet Numbers

•

Sheet numbers are found within
the architect’s title block.

•

Standardized format for sheet
numbers:
–

First letter indicates the craft.
–

Numbers indicate the type of
sheet.
–

Additional letters or numbers
indicate subdivisions or
subsequent pages.

Module 26110-23 – Basic Electrical Construction Documents

1.1.3 Approval Authorization

The approval blocks include:
•

Date checked for accuracy
•

Professional stamp
•

Design supervisor
•

Drawn
•

Checked
•

Approved
•

Owner’s approval

Module 26110-23 – Basic Electrical Construction Documents

1.1.4 Revision Information

•

Revision blocks or information
include any redrawing or
modifications made to the
drawings.

•

It is important to ensure
everyone is using the most
up-to-date set of drawings.

Module 26110-23 – Basic Electrical Construction Documents

1.1.5 Using a Legend

The legend block:
•

Shows symbols or lines used in a drawing
•

Sometimes called Symbols Used or Symbols List

Module 26110-23 – Basic Electrical Construction Documents

1.2.0 Drawing Types

The most common types of electrical drawings include:
•

Plans
•

Views
•

Detail drawings
•

Perspective drawings

Module 26110-23 – Basic Electrical Construction Documents

1.2.1 Site Plans

•

Site plans show how buildings
should be oriented on a piece
of property.

•

A property and topographic
survey is done first to locate
utilities and other information.

Module 26110-23 – Basic Electrical Construction Documents

1.2.2 Floor Plans

Floor plans show:
•

Rooms
•

Walls
•

Doors
•

Windows

Module 26110-23 – Basic Electrical Construction Documents

1.2.3 Elevation Views

Elevation views show:
•

The exterior face of a building
•

Front and rear elevations
•

Left and right elevations

Module 26110-23 – Basic Electrical Construction Documents

1.2.4–1.2.5 Sectional Views and Details

•

Sectional views are cutaways
that show hidden parts of a
structure.

•

A dashed line with special
symbols on a plan or elevation
will show where the section view
is.

•

Details are enlargements of parts
of the main drawing.

Module 26110-23 – Basic Electrical Construction Documents

1.3.0 Drafting Lines

•

There are many different types of
lines used in construction
drawings.
–

They depict different things.

•

There is no standard for drafting
lines.
–

Always check the legend.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (1 of 5)

Architectural drawings: Working drawings consisting of site plans, floor
plans, elevations, sectional views, details, and other information necessary
for the construction of a building.

Blueprints: Exact copies or reproductions of original drawings.

Contour lines: Curving lines on a site plan following a given elevation. The
space between contour lines tells the slope of the property, such as steep
when they are close together or fairly level when they are widely separated.

Detail drawing: An enlarged, detailed view taken from an area of a drawing
and shown in a separate view.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (2 of 5)

Dimensions: Sizes or measurements printed on a drawing.

Electrical drawing: A means of conveying a large amount of exact, detailed
information in an abbreviated form that electricians understand. It consists of
blocks, lines, symbols, dimensions, and notations to accurately convey the
designs to those who install the electrical system on a job.

Elevation view: An architectural drawing showing height and width, but not
depth; usually showing the front, rear, and sides of a building or object.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (3 of 5)

Floor plan: A drawing of a building as if the building was cut through
horizontally at about window level with the top portion removed. The floor
plan is what would appear if the remaining structure were viewed from
above.

Plan: A drawing made as though the viewer were looking straight down on
an object from above.

Scale: On a drawing, the relationship between an object’s actual size and
drawn size. Scale also refers to the measuring tool used to determine this
relationship.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (4 of 5)

Schedule: A systematic method of presenting equipment lists on a drawing
in tabular form.

Sectional view: A cutaway drawing that shows the inside of an object or
building.

Site Plan: A drawing showing the location of one or more buildings on the
building site. Such drawings frequently show topographical lines, electrical
and communication lines, water and sewer lines, sidewalks, driveways, and
similar information.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (5 of 5)

True north: The direction indicated on construction drawings that shows
how property lines and buildings are positioned on a site relative to a
compass or magnetic north.

Module 26110-23 – Basic Electrical Construction Documents

1.0.0 Section Review Question 1

1. A drawing contains an area circled in a cloud shape. This information is
often detailed in the _____.

a. legend block

b. approval block

c. revision block

d. engineer’s title block

Module 26110-23 – Basic Electrical Construction Documents

1.0.0 Section Review Question 1 Answer

1. A drawing contains an area circled in a cloud shape. This information is
often detailed in the _____.

a. legend block

b. approval block

c. revision block

d. engineer’s title block

Module 26110-23 – Basic Electrical Construction Documents

1.0.0 Section Review Question 2

2. Which of the following shows the face of a building?

a. Section view

b. Floor plan

c. Site plan

d. Elevation view

Module 26110-23 – Basic Electrical Construction Documents

1.0.0 Section Review Question 2 Answer

2. Which of the following shows the face of a building?

a. Section view

b. Floor plan

c. Site plan

d. Elevation view

Module 26110-23 – Basic Electrical Construction Documents

1.0.0 Section Review Question 3

3. What type of line is used on a drawing of a large structure to show where
one sheet of the drawing stops and the next begins?

a. Match line

b. Extension line

c. Section line

d. Break line

Module 26110-23 – Basic Electrical Construction Documents

1.0.0 Section Review Question 3 Answer

3. What type of line is used on a drawing of a large structure to show where
one sheet of the drawing stops and the next begins?

a. Match line

b. Extension line

c. Section line

d. Break line

Next…

2.0.0
Scale Drawings

Read Sections 2.0.0 through 2.4.0. Complete the 2.0.0 Section
Review.

Electrical

Module 26110-23

Basic Electrical Construction Documents

Copyright © 2024 by NCCER, Alachua, FL 32615. Published by Pearson. All rights reserved.

2.0.0 Scale Drawings

Module 26110-23 – Basic Electrical Construction Documents

Objective

2. Explain how to measure items on scale drawings.

a. Describe how to use an architect’s scale.

b. Describe how to use an engineer’s scale.

c. Describe how to use a metric scale.

Module 26110-23 – Basic Electrical Construction Documents

Performance Task

1. Using an architect’s scale, state the actual dimensions of a given drawing
component.

Module 26110-23 – Basic Electrical Construction Documents

2.0.0–2.1.0 Drawing to Scale

Drawings are scaled down to fit on
the sheets.
•

The size is reduced by a set
proportion.

Module 26110-23 – Basic Electrical Construction Documents

2.1.1 Understanding Scale

•

Scale is a relationship
between the measurements
on the plan and the
dimensions of the real
objects.

•

Always double-check the
scale.

Module 26110-23 – Basic Electrical Construction Documents

2.2.0–2.2.1 Using a Flat Architect’s Scale

•

A common type of architect’s scale shows a 1" = 1'-0" scale.

•

Each inch represents one foot and shows subdivisions of one foot.

Module 26110-23 – Basic Electrical Construction Documents

2.2.2 Using a Triangular Architect’s Scale

•

A triangular architect’s
scale has three sides,
each with two edges.

•

Each edge has two
scales, for a total of 12
different scales.

Module 26110-23 – Basic Electrical Construction Documents

2.3.0 Using an Engineer’s Scale

•

An engineer’s scale uses
decimal units of 10, 20, 30,
40, 50, and 60.

•

Each face has one
measurement per edge.

Module 26110-23 – Basic Electrical Construction Documents

2.4.0 Using a Metric Scale

Metric scales use units of 10 but are calibrated in metric dimensions instead
of inches and feet.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms

Architect’s scale: A special ruler that allows you to measure distances on
drawings as real-world distances in feet, inches, and fractions. An architect’s
scale measures distances in inches.

Engineer’s scale: A special ruler that allows you to measure distances on
drawings as real-world distances in decimals. An engineer’s scale measures
distances in decimal units.

Module 26110-23 – Basic Electrical Construction Documents

2.0.0 Section Review Question 1

1. If a floor plan of a building is drawn to a scale of 1⁄8" = 1'-0", a distance of
13⁄8" on the drawing would equal _____.

a. 1'-3" on the building itself

b. 8'-0" on the building itself

c. 11'-0" on the building itself

d. 13'-8" on the building itself

Module 26110-23 – Basic Electrical Construction Documents

2.0.0 Section Review Question 1 Answer

1. If a floor plan of a building is drawn to a scale of 1⁄8" = 1'-0", a distance of
13⁄8" on the drawing would equal _____.

a. 1'-3" on the building itself

b. 8'-0" on the building itself

c. 11'-0" on the building itself

d. 13'-8" on the building itself

Module 26110-23 – Basic Electrical Construction Documents

2.0.0 Section Review Question 2

2. The most common scaled rulers used in electrical drawings are the _____.

a. metric scale

b. architect’s scale

c. interval scale

d. ordinal scale

Module 26110-23 – Basic Electrical Construction Documents

2.0.0 Section Review Question 2 Answer

2. The most common scaled rulers used in electrical drawings are the _____.

a. metric scale

b. architect’s scale

c. interval scale

d. ordinal scale

Module 26110-23 – Basic Electrical Construction Documents

2.0.0 Section Review Question 3

3. Using a 1:20 scale on an engineer’s scale, a measurement of 2" on a
drawing would equal _____.

a. 5'

b. 10'

c. 20'

d. 40'

Module 26110-23 – Basic Electrical Construction Documents

2.0.0 Section Review Question 3 Answer

3. Using a 1:20 scale on an engineer’s scale, a measurement of 2" on a
drawing would equal _____.

a. 5'

b. 10'

c. 20'

d. 40'

Module 26110-23 – Basic Electrical Construction Documents

2.0.0 Section Review Question 4

4. A metric drawing scale of 1:1,000 typically depicts units in _____.

a. millimeters

b. centimeters

c. decimeters

d. meters

Module 26110-23 – Basic Electrical Construction Documents

2.0.0 Section Review Question 4 Answer

4. A metric drawing scale of 1:1,000 typically depicts units in _____.

a. millimeters

b. centimeters

c. decimeters

d. meters

Next…

3.0.0
Electrical Drawings

Read Sections 3.0.0 through 3.4.4. Complete the 3.0.0 Section
Review.

Electrical

Module 26110-23

Basic Electrical Construction Documents

Copyright © 2024 by NCCER, Alachua, FL 32615. Published by Pearson. All rights reserved.

3.0.0 Electrical Drawings

Module 26110-23 – Basic Electrical Construction Documents

Objective

3. Identify information on electrical drawings.

a. Identify electrical symbols.

b. Identify information on residential electrical drawings.

c. Explain how to read a set of commercial plans.

d. Describe how to read schedules, block diagrams, and schematic
diagrams.

Module 26110-23 – Basic Electrical Construction Documents

Performance Task

2. Make a material takeoff of the luminaires specified in the drawing
provided in the Performance Profile Sheet. The takeoff requires that all
luminaires be counted, and where applicable, the total number of lamps
for each luminaire type must be calculated. Fill these in on the
Performance Profile Task 2 Worksheet provided in the Performance
Profile Sheet.

Module 26110-23 – Basic Electrical Construction Documents

3.0.0–3.1.0 Reading Electrical Drawings

Electrical drawings are used to:
•

Estimate materials and labor
•

Provide information about how and where to install the system
•

Provide a map of the system once the installation is complete

Module 26110-23 – Basic Electrical Construction Documents

3.1.1 Electrical Symbols and Lines

Electrical symbols are not standardized.
•

The American National Standards
Institute (ANSI) and the
Consulting Engineers Council
(CED) have made
recommendations on symbols to
use.

Module 26110-23 – Basic Electrical Construction Documents

3.2.0–3.2.1 Branch Circuits

•

Drawings for residential projects are usually very basic.

•

NEC Article 220, Part II, Sections 220.10 through 220.16 provides
information on calculating branch circuit loads.

•

Branch circuits are shown on electrical drawings using a single line from
the panelboard to the outlet and from outlet to outlet.
–

Outlets are points where electrical equipment is connected.

Module 26110-23 – Basic Electrical Construction Documents

3.2.2 Residential Receptacle and Lighting Branch
Circuits

Branch circuits must meet the
requirements of NEC Section 210.52.
•

Receptacle outlets may not be
more than 12'apart.

Module 26110-23 – Basic Electrical Construction Documents

3.3.0–3.3.1 Electrical Site Plans

•

Commercial projects
and plans are more
complex than
residential projects.

•

Site plans include
information about
existing and new
utilities.

Module 26110-23 – Basic Electrical Construction Documents

3.3.2 Power Plans

Power plans show:
•

The part of the project
to which the sheet
applies.
•

The symbol list for both
power and lighting on
the project.

Module 26110-23 – Basic Electrical Construction Documents

3.3.3 Power Plan Details

Module 26110-23 – Basic Electrical Construction Documents

3.3.4–3.3.5 Correlating Information between Plans

The symbols for luminaires are drawn to indicate the physical shape and
approximate size of the fixture.

Module 26110-23 – Basic Electrical Construction Documents

3.4.0–3.4.1 Drawing Schedules

Schedules save time by providing much-needed information in one place.

Module 26110-23 – Basic Electrical Construction Documents

3.4.2 Block Diagrams

•

Block diagrams show the
arrangement of electric service
equipment.

•

Power riser diagrams also indicate
service-entrance conductors and
feeders.

Module 26110-23 – Basic Electrical Construction Documents

3.4.3 Schematic Diagrams

Schematic wiring diagrams are
normally used only in complicated
systems.

Module 26110-23 – Basic Electrical Construction Documents

3.4.4 Drawing Details

•

Detail drawings show a separate
item or portion of an electrical
system.

•

It provides all the information for
installing that section.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (1 of 3)

Block diagram: A single-line diagram used to show electrical equipment and
related connections.

One-line diagram: A drawing that shows, by means of lines and symbols,
the path of an electrical circuit or system of circuits along with the various
circuit components. Also called a single-line diagram.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (2 of 3)

Power-riser diagram: A single-line block diagram used to indicate the
arrangement of electric service equipment, service conductors and feeders,
and subpanels. Notes are used on power riser diagrams to identify the
equipment; indicate the size of conduit; show the number, size, and type of
conductors; and list related materials. A panelboard schedule is usually
included with power riser diagrams to indicate the exact components (panel
type and size), fuses, circuit breakers, etc. that are contained in each
panelboard.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (3 of 3)

Schematic diagram: A detailed diagram showing complicated circuits, such
as control circuits. A schematic diagram has no scale but shows the
components and their electrical connections.

Shop drawing: A drawing that is usually developed by manufacturers,
fabricators, or contractors to show specific dimensions and other pertinent
information concerning a particular piece of equipment and its installation
methods.

Module 26110-23 – Basic Electrical Construction Documents

3.0.0 Section Review Question 1

1. The letter designation SL on an electrical drawing indicates a _____.

a. limit switch

b. low-voltage switch

c. load switch

d. light switch

Module 26110-23 – Basic Electrical Construction Documents

3.0.0 Section Review Question 1 Answer

1. The letter designation SL on an electrical drawing indicates a _____.

a. limit switch

b. low-voltage switch

c. load switch

d. light switch

Module 26110-23 – Basic Electrical Construction Documents

3.0.0 Section Review Question 2

2. The load on a branch circuit should not exceed ____ of its rated capacity.

a. 100%

b. 90%

c. 80%

d. 70%

Module 26110-23 – Basic Electrical Construction Documents

3.0.0 Section Review Question 2 Answer

2. The load on a branch circuit should not exceed ____ of its rated capacity.

a. 100%

b. 90%

c. 80%

d. 70%

Module 26110-23 – Basic Electrical Construction Documents

3.0.0 Section Review Question 3

3. The two important items to note on power plans are the _____.

a. key plan and electrical symbols list

b. title block and scale

c. electrical symbols list and title block

d. sheet number and job number

Module 26110-23 – Basic Electrical Construction Documents

3.0.0 Section Review Question 3 Answer

3. The two important items to note on power plans are the _____.

a. key plan and electrical symbols list

b. title block and scale

c. electrical symbols list and title block

d. sheet number and job number

Module 26110-23 – Basic Electrical Construction Documents

3.0.0 Section Review Question 4

4. A tabular format for giving information on a drawing is called a _____.

a. symbol list

b. submittal

c. schematic diagram

d. schedule

Module 26110-23 – Basic Electrical Construction Documents

3.0.0 Section Review Question 4 Answer

4. A tabular format for giving information on a drawing is called a _____.

a. symbol list

b. submittal

c. schematic diagram

d. schedule

Next…

4.0.0
Specifications and Change Orders

Read Sections 4.0.0 through 4.3.0. Complete the 4.0.0 Section
Review.

Electrical

Module 26110-23

Basic Electrical Construction Documents

Copyright © 2024 by NCCER, Alachua, FL 32615. Published by Pearson. All rights reserved.

4.0.0 Specifications and Change Orders

Module 26110-23 – Basic Electrical Construction Documents

Objective

4. Describe how electricians use specifications.

a. Describe the primary types of information included in written
specifications.

b. Explain how specifications are formatted.

c. Identify document changes and the need for them.

Module 26110-23 – Basic Electrical Construction Documents

Performance Tasks

There are no Performance Tasks associated with this section.

Module 26110-23 – Basic Electrical Construction Documents

4.0.0–4.1.0 Content of Specifications

•

Written specifications are legally binding documents.

•

Specifications will:
–

Define and clarify the scope of the job.
–

Describe specific components to be used and requirements for
installation.
–

Identify required components by model and part numbers.

Module 26110-23 – Basic Electrical Construction Documents

4.2.0 Format of Specifications

•

The most commonly used format for specifications is MasterFormat®. The
MasterFormat® standard includes:
–

Four major groupings and 49 divisions
–

Numbering system that contains six digits

•

For electricians, the most important divisions to know include:
–

Division 25: Integrated Automation
–

Division 26: Electrical
–

Division 27: Communications
–

Division 28: Electronic Safety and Security

Module 26110-23 – Basic Electrical Construction Documents

4.3.0 Change Orders

•

Whenever there are differences between the working drawings and the
written specifications, submit a request for information. This request leads
to:
–

A change order will be issued that authorizes changes in the work.
–

Revisions may be made to drawings.

•

As-built drawings incorporate all changes and show the actual installation.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (1 of 2)

As-built drawings: A marked-up set of drawings, also called red lines, made
at the completion of the project, showing all changes made during the
construction project.

Change order: A formal document from the project manager or owner,
specifying one or more changes to the drawings, specifications, or project
scope. It will also state any changes in project cost.

Request for information: A formal document from the contractor seeking
clarification when errors, omissions, and discrepancies are found in or
between the construction documents.

Module 26110-23 – Basic Electrical Construction Documents

Trade Terms (2 of 2)

Written specifications: Written descriptions of what is required by the
owner, architect, and engineer in the way of materials and workmanship.
Together with working drawings, the specifications form the basis of the
contract requirements for construction.

Module 26110-23 – Basic Electrical Construction Documents

4.0.0 Section Review Question 1

1. A well-written specification document will contain _____.

a. elevation drawings

b. model and part numbers

c. NEC® references for installation

d. PPE requirements

Module 26110-23 – Basic Electrical Construction Documents

4.0.0 Section Review Question 1 Answer

1. A well-written specification document will contain _____.

a. elevation drawings

b. model and part numbers

c. NEC® references for installation

d. PPE requirements

Module 26110-23 – Basic Electrical Construction Documents

4.0.0 Section Review Question 2

2. The MasterFormat® division containing electrical specifications is _____.

a. Division 25

b. Division 26

c. Division 27

d. Division 28

Module 26110-23 – Basic Electrical Construction Documents

4.0.0 Section Review Question 2 Answer

2. The MasterFormat® division containing electrical specifications is _____.

a. Division 25

b. Division 26

c. Division 27

d. Division 28

Module 26110-23 – Basic Electrical Construction Documents

4.0.0 Section Review Question 3

3. A conflict between the drawings and the specifications is resolved by the
_____.

a. equipment supplier

b. electrical contractor

c. as-built drawings

d. change order

Module 26110-23 – Basic Electrical Construction Documents

4.0.0 Section Review Question 3 Answer

3. A conflict between the drawings and the specifications is resolved by the
_____.

a. equipment supplier

b. electrical contractor

c. as-built drawings

d. change order

Next…

Review for Module Testing

Complete the Review Questions at the end of the module and prepare
for the Module Test.