Chapter 19
Electrical Plans
Introduction
• Electrical plans:
– Display all circuits and systems used by the
electrical contractor during installation
– May be placed on floor plan or separate
• Electrical installation phases
– Temporary
– Rough-in electrical
– Finish electrical
Electric Terms and Definitions
• Common terms:
– Ampere, volt, watt
– Box
– Breaker
– Circuit
– Conductor, conduit
– Distribution panel
– Electrical work
– Ground
– Junction box
– Lighting outlet
– Meter and meter base
– Outlet
– Switch leg
– Temporary electric service
Electrical Circuit Design
• Discuss anticipated electrical needs
– Intended use of rooms
– Potential furniture placement
– Costs and budgets
• Electrical code requirements
– State size of some circuits and placement of
certain outlets and switches
Basic Electrical Design
Recommendations
• Electrical systems
– Should be designed for convenience of use
and to meet minimum code requirements
– Refer to the text for common codes and
convenience applications to consider when
designing electrical circuits
Home Automation
• Automation:
– Controlling and operating mechanical devices
other than human power
– Types of systems:
•
•
•
•
•
Entertainment centers
Computerized programming of house functions
Security systems
Radio frequency systems
Structured wiring systems
Electrical Design Considerations
• Basic considerations:
– Entry and entry foyer
– Patios and porches
– Living area
– Dining room and
kitchen
– Bedrooms and
bathrooms
– Laundry/utility room
–
–
–
–
–
–
–
Office or hobby room
Hallways and stairs
Garage
Outdoor outlets
Crawl spaces
Smoke detectors
Electronics
Smoke Detectors
• Provide safe exit opportunity through early
detection of fire and smoke
– UL 217 (Underwriters Laboratories)
– NFPA 72 (National Fire Protection Association)
• Installed in each sleeping room, and centrally
located in a corridor providing access to bedrooms
Carbon Monoxide Alarms
• Required in new residential construction
with fuel-fired appliances or attached
garage
– UL 2034
• Placed outside of each separate sleeping area in
immediate vicinity of bedrooms in dwelling units
• Installed in accordance with manufacturer’s
instructions
Universal Electrical Installations
• Design accommodating all ages and
possible disabilities should be considered
– Switch locations
– Convenience outlets
– Lighting
– Communications
Electrical Symbols
Light Fixture Design and
Placement
• Lighting options:
– General lighting
– Uniform down-lighting
– Non-uniform down-lighting
– Task lighting
– Accent lighting
– Light scallop
– Recessed lighting
Reflected Ceiling Plans
• Shows features located on ceiling
– View if reflected onto a mirror on the floor
• Same orientation as related to floor plan
– Found in set of construction drawings
– Often drawn by interior designers
– Typically contains ceiling construction and
finish sections, details, and specifications
• Also shows special features
Electrical Schedules
Electrical Wiring Specifications
• Service entrance and meter base
installation considerations:
– What is the service capacity to be installed?
– Where is the service entrance to be located?
– Where will the meter base be located?
– Where will the distribution panel be located?
Metrics in Electrical Installations
• Electrical conduit designations are
expressed in millimeters
– Conduit is a metal pipe, fiber pipe, or tube
used to enclose a electrical conductors
•
•
•
•
Produced in decimal inch dimensions
Identified in nominal inch sizes
Nominal size is referred to as conventional size
Actual size remains in inches but labeled in metric
•
•
•
•
Steps in Drawing the Electrical
Plan
Draw all light fixtures
Place all electrical outlets
Draw all additional electrical symbols
Letter all switch locations and provide
characteristics
Steps in Drawing the Electrical
Plan (cont’d.)
• Draw electrical circuits or switch legs from
switches to fixtures using a dashed arc line
• Letter all notes, drawing title, and scale
• Add general electrical notes, fixture
schedules, and symbol legends
Drawing the Upper Floor
Electrical Plan
• Use the same steps to draw upper floor
plan electrical layout
– Refer to Figure 19-22
• Not all offices display an electrical symbol legend,
because standard symbols are typically used
• Good location for electrical fixture schedules or
electrical-related schedules
• There are no electrical schedules for the model
house
Electrical Plan Drawing Checklist
• Refer to the text for a electrical plan
drawing checklist
– Check off items while working on an electrical
plan
• Ensures everything necessary is included