Par 11-271 Page 11-586 SECTION 20. ELECTRICAL AND ELECTRONIC SYMBOLS
GENERAL. The electrical and electronic symbols shown here are those that are likely to be encountered by the aviation maintenance technician. They are in accordance with ANSI-Y32.2-1975.
SYMBOLS. Only those symbols associated with aircraft electrical and electronic wiring have been listed in general. Refer to ANSI- Y32.2-1975 for more specific detail on each symbol.
TABLE 11-27. Electronic/Electrical Symbols.
Symbol Meaning
Adjustability Variability
Radiation Indicators
Physical State Recognition
Test-Point Recognition
Polarity Markings
Direction of Flow of Power, Signal, or Information
Kind of Current
Envelope Enclosure
Shield Shielding
Special Connector or Cable Indicator
Par 11-271 Page 11-587 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Resistor
Capacitor
Antenna
Battery
Thermal Element Thermomechanical Transducer
Thermocouple
Spark Gap Ignitor Gap
Continuous Loop Fire Detector (Temperature Sensor)
Ignitor Plug
Par 11-272 Page 11-588 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Transmission Patch Conductor Cable Wiring
Distribution Lines Transmission Lines
Alternative or Conditioned Wiring
Associated or Future
Par 11-272 Page 11-589 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Intentional Isolation of Direct-Current Path in Coaxial or Waveguide Applications
Waveguide
Strip-Type Transmission Line
Termination
Circuit Return
Pressure-Tight Bulkhead Cable Gland Cable Sealing End
Switching Function
Electrical Contact
Par 11-272 Page 11-590 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Basic Contact Assemblies
Magnetic Blowout Coil
Operating Coil Relay Coil
Switch
Pushbutton, Momentary, or Spring-Return
Par 11-272 Page 11-591 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Two-Circuit, Maintained, or Not Spring-Return
Nonlocking Switching, Momentary, or Spring- Return
Locking Switch
Combination Locking and Nonlocking Switch
Key-Type Switch Lever Switch
Par 11-272 Page 11-592 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Selector or Multiposition Switch
Safety Interlock
Limit Switch Sensitive Switch
Switches with Time-Delay Feature
Flow-Actuated Switch
Par 11-272 Page 11-593 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Liquid-Level Actuated Switch
Pressure- or Vacuum-Actuated Switch
Temperature-Actuated Switch
Thermostat
Flasher Self-Interrupting Switch
Foot-Operated Switch Foot Switch
Switch Operated by Shaft Rotation and Responsive to Speed or Direction
Switches with Specific Features
Par 11-272 Page 11-594 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Governor Speed Regulator
Relay
Inertia Switch
Mercur Switch
Terminals
Par 11-272 Page 11-595 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Cable Termination
Connector Disconnecting Device
Connectors of the Type Commonly Used for Power-Supply Purposes
Test Blocks
Coaxial Connector
Waveguide Flanges Waveguide Junction
Par 11-272 Page 11-596 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Fuse
Lightning Arrester Arrester Gap
Circuit Breaker
Protective Relay
Audible-Signaling Device
Microphone
Par 11-272 Page 11-597 TABLE 11-27. Electronic/Electrical Symbols (continued).
Symbol Meaning
Handset Operator’s Set
Lamp
Visual-Signaling Device
Mechanical Connection Mechanical Interlock
Mechanical Motion
Clutch Brake