Unit 3- Schematic Symbols

1
Unit 3- Schematic Symbols

• EET 110 Electronics Survey I

2
Topics to Cover

• Types of representations
• Symbols for blueprint drawing
• Symbols for electrical schematics

3
Representations

• Prints
• Clearly show
• Types of electric devices and conductors
• Where they are located
• How they are connected to each other
• Supplied by builder, archetect, owner or
  electrician

4
Representations-Prints
S
5
Representations (cont.)

• Schematics
• Clearly show
• Types of devices and conductors
• Where they should be located
• Electrical Connections
• Typically for controls or equipment
• Provided by engineer, manufacturer

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Representations-Schematics
Source
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Representations (cont.)

• Pictorials
• Clearly show
• Types of devices and conductors
• Where they should be located
• How they are connected together
• Electrical connections
• Detail inside each box
• Not used in industry due to complexity

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Representations-Pictorial
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Junction Box

• Commonly Called a J-Box
• Used for
• Code requires all splices in a box
• Saves labor
• Saves time
• Saves cost

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Junction Box
Print
Schematic
Pictorial
J
11
Lamp Holder
Print
Schematic
Pictorial
L
12
Pull Switch
Print
Schematic
Pictorial
S
13
Duplex Convenience Receptacle.
Print
Schematic
Pictorial
14
Split Duplex Convenience Receptacle.
Print
Schematic
Pictorial
S
15
Convenience Receptacle other than Duplex
Print
Schematic
Pictorial
3
3
Number indicates the number of receptacles (1, 3,
etc.)
16
Weatherproof Receptacle
Print
Schematic
Pictorial
WP
WP
17
240 V Receptacle
Print
Schematic
Pictorial
18
Range Receptacle
Print
Schematic
Pictorial
R
R
19
Drier Receptacle
Print
Schematic
Pictorial
D
D
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Ground Fault Circuit Interrupter

• GFCIs open if current leakage to ground exceeds
  .006 A
• Normally the current going to the appliance (hot)
  and the current returning to the source (neutral)
  are equal
• Any fault grater than .006A opens and deenergizes
  the circuit.

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GFCI
Print
Schematic
Pictorial
GFCI
GFCI
22
Floor Receptacle
Print
Schematic
Pictorial
23
Push Button Switches
Print
Schematic
Pictorial
S
Normally Open
Normally Closed
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SPST 2 way
Print
Schematic
Pictorial
S
25
SPDT 3 way
Print
Schematic
Pictorial
S3
26
DPDT 4 way
Print
Schematic
Pictorial
S4
27
Buzzer
Print
Schematic
Pictorial
28
Outside telephone
Print
Schematic
Pictorial
29
Interconnecting Telephone
Print
Schematic
Pictorial
30
Battery-- Source
Print
Schematic
Pictorial