Table of Contents

Appendix A. Electrical Symbols

1.0 General Electrical Symbols

No.	DESCRIPTION	SYMBOL
1.1	Lightning Arrester
1.2	Surge Arrester
1.3	Ground (Earth)
1.4	Ground (Frame)
1.5	Service Entrance (Power)
1.6	Service Entrance (Telephone)
1.7	Kilowatt-Hour Meter
1.8	Safety Switch
1.9	Disconnect Switch
1.10	Transfer Switch
1.11	Circuit Breaker
1.12	Fuse
1.13	Fuse Cut-out
1.14	Main Distribution Panelboard
1.15	Power Panelboard
1.16	Lighting Panelboard
1.17	Motor Controller, 3 Pole Across-The-Line
1.18	Combination Type Motor, Controller, ATL, Starter Plus Fused Disconnect Switch
1.19	Combination Type Motor, Controller, ATL, Starter Plus Circuit Breaker

1.21	Switches
	1. Single Pole
	2. Duplex (2 single pole switches on one switch pole)
	3. Triplex (3 single pole on one switch pole)
	4. Double Pole
	5. Three-Pole
	6. Three-Way
	7. Four-Way
	8. Automatic Door
	9. Key Operated
	10. Master Selector
	11. Remote Control
1.22	Junction Box
1.23	Pull Box
1.24	Riser Up
1.25	Riser Down
1.26	Circuit Homerun (Number Indicates Circuit No)
1.27	Push Button
1.28	Buzzer (Indicate Voltage)
1.29	Bell (Indicate Voltage)
1.30	Horn
1.31	Amplifier
1.32	Annunciator
1.33	Loudspeaker
1.34	Telephone Exchange
1.35	Telephone Terminal Cabinet
1.36	Fire Alarm System
	1. Manual
	2. Control Panel
	3. Heat Detector
	4. Flame Detector
	5. Smoke Detector
	6. Ionization Detector
1.37	Wiring Symbols (cross-lines indicate number of wires)
	1. Conduits
	2. Open Wiring
	3. Underground
	4. Emergency
	5. Fire Alarm
	6. Telephone
	7. Intercom
	8. Bell System
	9. TV Antenna
	10. Close Circuit Television
	11. Music
	12. Clock
1.38	Battery
1.39	Resistor
1.40	Inductor
1.41	Capacitor
1.42	Thermocouple
1.43	Converter, Transmitter
1.44	Single-Phase Bridge Rectifier
1.45	Plug and Socket Device
1.46	Filament Lamp
1.47	Discharge Lamp

2.1	AC Generator
2.2	DC Generator
2.3	AC Motor
2.4	DC Motor
2.5	Universal Motor
2.6	Motor-Generator
2.7	Three-Phase Induction Motor with Slipring Rotor
2.8	Three-Phase Induction Motor with Squirrel-Cage Rotor
2.9	Three-Phase Induction Motor with Squirrel-Cage Rotor Both Ends of the Winding Brough out
2.10	Single-Phase Induction Motor with Squirrel Cage Rotor
2.11	Three-Phase Synchronous Generator, Star Connected, Neutral Not Brough Out
2.12	Three-Phase Synchronous Generator, Star Connected, Neutral Brough Out
2.13	Three-Phase Synchronous Generator with Permanent Magnet Excitation
2.14	Single-Phase Synchronous Generator with Permanent Magnet Excitation
2.15	DC-Shunt-Wound Generator, Interpole Windings Arranged in Symmetry with Armature
2.16	DC-Shunt-Wound Motor, Interpole Windings Arranged in Symmetry with Armature
2.17	DC Generator with Permanent Magnet Excitation
2.18	Three-Phase Commutator Motor with Shunt Characteristic, Rotor Fed
2.19	Three-Phase Commutator Motor with Series Characteristic
2.20	Change-Pole Squirrel-Cage Induction Motor for Charging from 8 to 4 Poles, According to Dahlander
2.21	Change-Pole Squirrel-Cage Induction Motor with Two Separate Windings for Charging from 8 to 4 Poles and 6 Poles Respectively

3.1	Transformer with Two Separate Windings
3.2	Transformer with Three Separate Windings
3.3	Auto-Transformer
3.4	Reactor
3.5	Current Transformer
3.6	Voltage (Potential) Transformer

4.1	Thermal Overload Release
4.2	Magnetic Overcurrent Release
4.3	Undervoltage Release
4.4	Open-Circuit Shunt Release

5.1	Make Contact (NO)
5.2	Break Contact (NC)
5.3	Change-Over Contact
5.4	Change-Over Contact Make-Before-Break
5.5	Time-Delayed Contacts
	1. Make Contact, Delayed Make
	2. Break Contact, Delayed Break
	3. Make Contact, Delayed Break
	4. Break Contact, Delayed Make
5.6	Contactor with Thermal Overload Releases
5.7	Triple-Pole Circuit Breaker with Latching Mechanism
5.8	Triple-Pole Load-Break Switch
5.9	Triple-Pole Fused Isolator
5.10	Triple-Pole Isolator
5.11	Isolating Link, Change-Over Type
5.12	Single-Throw Switch, Manually Operated
5.13	Spring-Return Switches
	1. Manually Operated with 1 Normally Opened Contact
	2. Manually Operated with 1 Normally closed Contact
	3. Foot Operated
	4. Cam Operated
	5. Flow Speed Actuated
	6. Pressure Actuated
	7. Temperature Actuated
	8. Liquid Level Actuated

7.1	Electronic Valve, Diode
7.2	Electronic Valve, Triode
7.3	Single Anode Rectifier Vessel with Mercury Cathode (Ignition)
7.4	Semiconductor Diode
7.5	Limiting Diode Uni-/Bidirectional
7.6	Transistor
7.7	Thyristor, General Symbol
7.8	Photo-Resistor Bidirectional
7.9	Photoelectric Cell
7.10	Hall Generator
7.11	Junction Field Effect Transistor with N-Type Channel

8.1	Ammeter
8.2	Voltmeter
8.3	Double Voltmeter
8.4	AC Kilowatthhour-Meter
8.5	Varbourmeter
8.6	Wattmeter
8.7	Kilowatt-meter, Recording
8.8	Varmeter, Recording
8.9	Volt-Ampere Reactive Meter
8.10	Power-Factor Meter
8.11	Frequency Meter
8.12	Tachometer
8.13	Ground Detector
8.14	Synchronoscope
8.15	Ohmmeter
8.16	Hour Meter, Running
8.17	Instrument Shunt
8.18	Synchro Rotor and Stator Three-Phase
8.19	Synchro Rotor Single-Phase Stator Three-Phase

9.1	“AND” Gate
9.2	“OR” Gate
9.3	“NOT” Gate, Negater
9.4	“NAND” Gate i.e., “AND” with Negated Output
9.5	“NOR” Gate i.e., “OR” with Negated Output
9.6	Exclusive OR Gate
9.7	Delay Element, General Symbol
9.8	Delay Element with Special Delay Times
9.9	Bistable Element, General Symbol
9.10	Monostable Element, Single Shot
9.11	RS Bistable Element
9.12	T Bistable Element, Binary Divider, Complementing Element
9.13	Bidirectional Shift Register
9.14	Four-Stage Bidirection Counter with Parallel Loading and Common Resets
9.15	Negating Input
9.16	Negating Output
9.17	Input with Polarity Indicator
9.18	Output with Polarity Indicator
9.19	Static Input
9.20	Dynamic Input
9.21	Negated Dynamic Input
9.22	Inhibiting Input
9.23	Negating Inhibiting Input
9.24	Input Not Carrying Logic Information
9.25	Output Not Carrying Logic Information
9.26	Extension Input