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 | ![]() |
1.20 | Outlets | Ceiling | Wall |
1. Incandescent Lamp | ![]() | ![]() | |
2. Vapor Discharge Lamo | ![]() | ![]() | |
3. Drop Cord Lamp | ![]() | ||
4. Exit Lamp | ![]() | ![]() | |
5. Fluorescent Lamp | ![]() | ![]() | |
6. Lamp Outlet with Pull Switch | ![]() | ![]() | |
7. Outlet with Blank Cover | ![]() | ![]() | |
8. Fan | ![]() | ![]() | |
9. Clock | ![]() | ![]() |
1.20 | Outlets (continuation) | |
10. Single Convenience | ![]() | |
11. Duplex Convenience | ![]() | |
12. Weatherproof Convenience | ![]() | |
13. Cooking Range | ![]() | |
14. Convenience with Switch | ![]() | |
15. Special Purpose (ACU, WH, D, R, etc.) | ![]() | |
16. Floor (P,T,I) | ![]() | |
17. Antenna | ![]() | |
18. Microphone | ![]() | |
19. Telephone | ![]() | |
20. Intercom | ![]() |
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 | ![]() |
2.0 Rotating Machines
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 | ![]() |
3.0 Transformers and Reactors
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 | ![]() |
4.0 Releases
4.1 | Thermal Overload Release | ![]() |
4.2 | Magnetic Overcurrent Release | ![]() |
4.3 | Undervoltage Release | ![]() |
4.4 | Open-Circuit Shunt Release | ![]() |
5.0 Switchgear
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 | ![]() |
6.0 Switchboard
6.1 | Main Switchboard | ![]() |
6.2 | Auxiliary Switchboard | ![]() |
6.3 | Emergency Switchboard | ![]() |
6.4 | Motor Control Center | ![]() |
7.0 Valves(Tubes), Semiconductors Elements
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. Measurement Devices
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 | ![]() |
9.0 Digital Information Processing
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 | ![]() |