Transcript Document

Chapter
29
Electrical Plans
Objectives
• Describe an electrical plan and identify its
features.
• Identify typical electrical symbols found on a
residential electrical plan.
• Draw an electrical plan for a residential structure
using manual drafting techniques.
• Draw an electrical plan for a residential structure
using CADD.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Electrical Plan
• Electrical plan shows location and type of
electrical equipment to be used
– Plan view section
– Usually traced from floor plan
– Shows meter distribution panel, outlets, switches,
and special features
– Identifies number and types of circuits
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Required Information
•
•
•
•
•
Service entrance capacity
Meter, distribution panel location
Location, placement, type of switches
Location, type of lighting fixtures
Special electrical equipment
• Number, type of circuits
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Required Information
• Electrical fixture schedule
• Symbols, legends, and notes
• Required amperage rating of service is shown
beside distribution panel
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Common Electrical Symbols
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Service Entrance
• Locate service entrance equipment close to
service drop
• Main breaker should be close to meter
• Locate service entrance close to largest energy
users
• Larger loads require larger conductors
• Shorter runs reduce voltage drops
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Employability
• Negotiation
– Process of coming to agreement on an issue that
requires all parties to give and take a little to
achieve intended result
– Begins with trying to understand the other person’s
interests
– Together try to reach possible solutions that meet
mutual concerns
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Meters
• Outside location is preferred, but meter can be
located inside or outside
• Smart meters can be read remotely by utility
company
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Switches
• Number and placement of switches is related to
number of lighting fixtures, switched outlets, and
equipment
• Select logical location for each switch
• Use proper symbols to show type of switch
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Switches
• On electrical plan, switches are shown connected
to fixtures, appliances, and outlets they operate
• Thin, curved hidden line or centerline shows
connection
– Lines do not represent actual wiring, but only
elements connected
• Use SPLINE or POLYLINE in CADD
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Receptacle Outlets
•
•
•
•
Place outlets every 6' to 8' along all walls
Outlets are usually 120-volt duplex
Some duplex outlets may be split-wired
Receptacle outlets should be grounded or GFCI to
prevent shock
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Receptacle Outlets
• Receptacle outlets may be switched or always
“hot”
• Consider furniture arrangement when locating
switches and outlets
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Special-Purpose Outlets
• Special-purpose receptacle outlets may have one
or several receptacles
• Unique symbols should be identified in a legend
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Traditional Lighting
• Two types of lights have been commonly used
• Incandescent light
– Screw-in bulb
• Fluorescent light
– Tube
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Energy-Efficient Alternatives
• Compact fluorescent lightbulbs (CFLs)
– Contain mercury
• Light-emitting diode (LED) lights
– Multiple colors; many uses
• Electronic-stimulated luminescence (ESL) lights
– Up to 70% more energy-efficient than incandescent
bulbs
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Lighting Fixtures
• Trend is toward more freestanding lamps and
fewer ceiling-mounted fixtures
• Recessed lighting fixtures for hallways, foyers, or
special emphasis
• Track lighting is another option
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Exterior Lighting
• Exterior light fixtures should be rated for exterior
applications
• Plan adequate lighting for:
–
–
–
–
–
Walks
Drives
Porches
Patios
Other outside areas
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Lighting Fixture Schedule
• Use proper symbol for each lighting fixture at
actual location
• Include lighting fixture schedule in electrical plan
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Green Architecture
• Phasing out the incandescent lightbulb
– In United States, higher-energy bulbs were
restricted first, with phase-out to be completed in
2014
– Some bulbs are exempt from restrictions, such as
appliance lamps
– Keep up-to-date with new technologies and
incorporate them into designs when possible
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Other Devices
•
•
•
•
•
•
•
Telephone jacks
Intercom system
Home security devices
TV antenna jack
Cable or satellite TV jack
Door chimes
Audio outlets
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Branch Circuits
• Electrical plan indicates number and type of
branch circuits
• Circuit data is generally shown as note, chart, or
diagram on electrical plan
• Number of lighting, small-appliance, and individual
circuits should be listed
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Manual Drafting: Electrical Plan
1. Trace exterior and interior walls and major
appliances from floor plan.
2. Locate meter and distribution panel. Indicate
voltage and amperage rating. Locate telephone
junction box and home security or automation
wiring enclosure. Check building code
requirements.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Manual Drafting: Electrical Plan
3. Show all receptacle outlets using proper symbols.
4. Locate all ceiling and wall lighting outlets. Use
standard lighting symbols.
5. Show all special-purpose outlets and fixtures.
6. Locate switches and connect them to outlets and
lighting fixtures they operate.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Manual Drafting: Electrical Plan
7. Add lighting fixture schedule and symbol legend, if
needed.
8. Note number and type of circuits required.
9. Letter all other notes and title, scale, and sheet
number.
10. Check drawing for accuracy and completeness.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Residential Electrical Plan
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
CADD: Electrical Plan
1. If electrical plan is to be a separate file, open floor
plan drawing and save it with new name. If
combining electrical plan with floor plan, create
set of layers specifically for electrical plan and
lock or freeze all other layers.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
CADD: Electrical Plan
2. Locate meter and distribution panel. Indicate
voltage and amperage rating. Locate telephone
junction box and home security or automation
wiring enclosure. Double-check local building
codes.
3. Insert symbols for receptacle outlets, placing them
on electrical symbols layer. Indicate receptacle
types.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
CADD: Electrical Plan
4. Insert symbols for ceiling and wall lighting outlets
on electrical symbols layer.
5. Insert symbols for special-purpose outlets and
fixtures on the electrical symbols layer.
6. Insert symbols for switches on electrical symbols
layer.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
CADD: Electrical Plan
7. Connect switches to outlets and lighting fixtures
they operate. Use hidden or centerline linetype
with SPLINE command or Spline option of
POLYLINE command. Place these lines on
separate layer to achieve proper line width when
plotting.
8. Add lighting fixture schedule and symbol legend,
if needed.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
CADD Drafting Procedure
9. Add note indicating number and type of required
circuits. Create other notes and add title, scale,
and sheet number. Place specific notes on their
own layer.
10. Check drawing for accuracy and completeness.
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.
Residential Electrical Plan Drawn Using
CADD
© Goodheart-Willcox Co., Inc.
Permission granted to reproduce for educational use only.