Transcript 20-electrical

Electrical Plans
Electrical Plans
• Displays all of the circuits and systems to
be used by the electrical contractor during
installation
• Items to show on plans
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all outlets
all light fixtures connected to switches
all switches connected to light fixtures
all miscellaneous and low voltage items
• no connection necessary with low voltage items
– power panel and electrical meter
Electrical Plans
Methods used to show electrical systems on drawings
– 1 Add-on existing plans along with all other symbols, information, a
dimensions
• common practice on simple floor plans
• eliminates extra sheets and simplifies working drawings
• sometimes makes drawings difficult to read
– 2 Separate sheets for electrical information
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common practice on complex floor plans
separates electrical information from other drawing data
requires time to duplicate floor plans unless CAD dwgs
adds more blueprints to set of working drawings
Electrical Plans Example
Size and Drafting the Symbols
As noted on handout (units given below are full size units taken
from the 16 scale)
– Size of outlet symbol = 1/8” diameter circle
– Size of light fixture symbol = 1/4” diameter circle
– Size of fluorescent symbol = 1/8” x 1” (6”x48” real size)
– Size of switch symbol = 1/8” lettering
– Size of push button symbol = 3/16” square
– Size of electrical panel = 3/8”long and fill 1/2 of wall
– Size of meter base, etc. = 1/4” square
Outlets
• Symbol
– as shown on
plan
• Wall View
– finished state
• Description
– explanation
Duplex Outlet with Switch
Appliance vs. Voltage and Symbol
• Refrigerator
120 volts
• Stove
240 volts
• Hood
120 volts
R
H
• Oven
240 volts
• Garbage Disposal 120 volts
• Dishwasher
120/240 volts
O
GD
Appliance vs. Voltage and Symbol
• Clothes washer
120 volts
• Clothes dryer
240 volts
• Air Conditioner 120/240 volts
• Water heater
• Furnace
AC
240 volts
120/240 volts
WH
F
Light
Fixtures
• Ceiling/Wall
fixtures
– surface
– recessed
• Fan (exhaust)
• Junction box
• Fluorescent fixtures
Switches
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Single Switch
3-way Switch
4-way Switch
Dimmer Switch
Timer Switch
Electrical Symbols - Miscellaneous
Electrical Code/Drafting Practice
• Duplex convenience outlets (wall plugs)
should be a maximum of 12’ apart. Closer
spacing is desirable, although economy is a
factor. Code reads: “no point along a wall
is further than 6’ from an outlet.”
• Duplex convenience outlets should be no
more than 6’ from a corner
• There should be a duplex outlet in any
usable wall space over 2’ long
• Place a (one) duplex outlet in a hallway
Outlet Placement Example
Electrical Code/Drafting Practice
Kitchen /Bathroom areas
– usable counter space of 12” & greater require an outlet
– outlets are required every 48” of counter space (with
new code text is in error)
– note mounting height for outlets above counter (+44”)
– special purpose outlets for garbage disposal, dishwasher,
separate oven, and hood
– range outlet for electric range
– GFI or GFCI protection for any outlets in rooms with a
water source.
Switch/Outlets Examples
Switching Examples
Switching
• Switch symbol and
fixture are
connected with a
dashed line using a
irregular curve
• Single Switching
• 3-Way Switching
• 4-Way Switching
Switching an Outlet
Switching a Porch Light
+(MOUNTING
HEIGHT)
Electrical Plan Example
Special Project Elect Plans (50 Points)
• Add electrical symbols and all electrical
information to your plans:
– Foundation plan (3 light +switch, one outlet and
special purpose outlet for water heater)
– First level floor plan (two exterior WP outlets, lights
at all entrances, elect range w/ hood above, garbage
disposal, dishwasher outlet, and washer/dryer outlets)
– Second level floor plan (exhaust fans in bathrooms, 3way switch to 1st floor for stair light)
– Complete an electrical schedule (10 points) for all the
symbols used similar to one shown in Handout
Electrical
Symbol Schedule
• Purpose of schedule
is to identify and
describe electrical
symbols used in the
set of working
drawings
• Categories
– Symbols
– Descriptions