INDUSTRIAL ELECTRICAL SYMBOLS . . .
                                                                                                CIRCUIT BREAKER
      DISCONNECT                     CIRCUIT                   CIRCUIT BREAKER CIRCUIT BREAKER W/ THERMAL AND
                                  INTERRUPTER                  WITH THERMAL OL WITH MAGNETIC OL   MAGNETIC OL




        LIMIT SWITCHES                                         PRESSURE AND LIQUID TEMPERATURE-
                                          FOOT                    VACUUM    LEVEL    ACTUATED     FLOW SWITCH
      NORMALLY          NORMALLY        SWITCHES                                                (AIR, WATER, ETC.)
        OPEN             CLOSED                                  SWITCHES  SWITCH     SWITCH


                                            NO                 NO                    NO               NO                  NO

        HELD             HELD
       CLOSED            OPEN               NC                 NC                    NC               NC                  NC

                                                                     SYMBOLS FOR STATIC SWITCHING CONTROL DEVICES
       SPEED (PLUGGING)                 ANTI-PLUG
                                                                    STATIC SWITCHING CONTROL IS A METHOD OF SWITCHING
                                                                    ELECTRICAL CIRCUITS WITHOUT USE OF CONTACTS,
         F                    F                       F             PRIMARILY BY SOLID-STATE DEVICES. USE SYMBOLS
                                                                    SHOWN IN TABLE AND ENCLOSE THEM IN A DIAMOND.




                                                                    INPUT COIL       OUTPUT NO              LIMIT SWITCH NO    LIMIT SWITCH NC




                              R                       R




                                                                        SELECTOR
        TWO-POSITION                        THREE-POSITION                                   TWO-POSITION SELECTOR PUSHBUTTON

                                                                                                                  SELECTOR POSITION
  J       K                             K
                         J    K     J        L                  J   K   L                                         A                   B
                                                                                 A   B       CONTACTS
              A1                                 A1                          1           2                      BUTTON             BUTTON
                   A1    X                                A1   X                                           FREE DEPRESSED FREE DEPRESSED
              A2                                 A2                          3           4
                   A2         X                           A2            X                       1 2         X
                                                                                                3 4                   X        X          X
      X-CONTACT CLOSED                      X-CONTACT CLOSED                                                     X - CONTACT CLOSED

                                                                    PUSHBUTTONS
                             MOMENTARY CONTACT                                                   MAINTAINED CONTACT                ILLUMINATED
       SINGLE                DOUBLE              MUSHROOM                   WOBBLE              TWO                  ONE
       CIRCUIT               CIRCUIT               HEAD                      STICK             SINGLE              DOUBLE
                                                                                               CIRCUIT             CIRCUIT                R
                         NO AND NC

NO



NC


©1999 American Technical Publishers, Inc.
. . . INDUSTRIAL ELECTRICAL SYMBOLS . . .
                                            CONTACTS                                                           OVERLOAD RELAYS
                                                         TIMED CONTACTS - CONTACT ACTION                       THERMAL       MAGNETIC
               INSTANT OPERATING
                                                             RETARDED AFTER COIL IS:
    WITH BLOWOUT             WITHOUT BLOWOUT             ENERGIZED                  DE-ENERGIZED
    NO           NC           NO            NC       NOTC         NCTO             NOTO         NCTC




                                       SUPPLEMENTARY CONTACT SYMBOLS
             SPST NO                             SPST NC                                   SPDT                            TERMS

     SINGLE               DOUBLE         SINGLE              DOUBLE               SINGLE              DOUBLE
     BREAK                BREAK          BREAK               BREAK                BREAK               BREAK                 SPST
                                                                                                                         SINGLE-POLE,
                                                                                                                        SINGLE-THROW

                                                                                                                            SPDT
                                                                                                                         SINGLE-POLE,
                                                                                                                        DOUBLE-THROW

                                                                                                                            DPST
                                                                                                                        DOUBLE-POLE,
           DPST, 2NO                             DPST, 2NC                                 DPDT                         SINGLE-THROW

     SINGLE               DOUBLE         SINGLE              DOUBLE               SINGLE              DOUBLE                DPDT
     BREAK                BREAK          BREAK               BREAK                BREAK               BREAK              DOUBLE-POLE,
                                                                                                                        DOUBLE-THROW

                                                                                                                            NO
                                                                                                                       NORMALLY OPEN

                                                                                                                             NC
                                                                                                                       NORMALLY CLOSED

                              METER (INSTRUMENT)                                                         PILOT LIGHTS
  INDICATE         TO INDICATE FUNCTION OF METER OR INSTRUMENT,                                   INDICATE COLOR BY LETTER
   TYPE BY         PLACE SPECIFIED LETTER OR LETTERS WITHIN SYMBOL.
   LETTER                                                                              NON PUSH-TO-TEST                 PUSH-TO-TEST
                AM or A      AMMETER                VA        VOLTMETER
      V           AH         AMPERE HOUR           VAR        VARMETER
                      A      MICROAMMETER         VARH        VARHOUR METER                        A                            R

                  mA         MILLAMMETER            W         WATTMETER

      AM
                  PF         POWER FACTOR           WH        WATTHOUR METER
                   V         VOLTMETER

  INDUCTORS                                                                 COILS
    IRON CORE                                                         DUAL-VOLTAGE MAGNET COILS
                                                                                                                            BLOWOUT
                                                                                                                              COIL
                                                             HIGH-VOLTAGE                         LOW-VOLTAGE

                                                                       LINK                            LINKS
                                                         1    2         3     4             1     2            3   4
    AIR CORE




©1999 American Technical Publishers, Inc.
. . . INDUSTRIAL ELECTRICAL SYMBOLS . . .
                                                                   TRANSFORMERS
       AUTO         AIR CORE             CURRENT                     CONTROL TRANSFORMER                                                     AUTOTRANSFORMER
                                                                                                                                               FOR REDUCED-
                                                                                                                                             VOLTAGE STARTING
                                                               SINGLE-                             DUAL-
                                                              VOLTAGE                             VOLTAGE                            %                                            %
                                                                                                                                     50                                           50
                                                                                                 H3         H2
                                                              H1         H2            H1                          H4                65                                           65


                                                                                                                                     80                                           80


                                                                                                                                     100                                          100
                                                             X2           X1           X2                          X1                    0                                         0



                                                                         AC MOTORS
       SINGLE-               SEPARATE PHASE,                                                          SEPARATE WINDING,                            CONSTANT-TORQUE,
                                                                   THREE-PHASE
       PHASE                    TWO-SPEED                                                                TWO-SPEED                                    TWO-SPEED

  T1               T2        HIGH        COM         LOW      T1              T2       T3             T1                  T11
                                                                                                                                                                   T4
                              T1          T2          T3

                                                                                                                                                            T3               T1




                                                                                                 T3          T2    T13             T12                 T5          T2             T6

  VARIABLE-TORQUE,                   CONSTANT-                       WYE/DELTA,                                   WYE-CONNECTED, PART WINDING,
     TWO-SPEED                      HORSEPOWER,                      REDUCED-                                          REDUCED-VOLTAGE
                                     TWO-SPEED                        VOLTAGE
              T4                               T4
                                                                                                                  T1     T2   T3                                 T7 T8      T9
                                                                                                                                              T5
                                                                         T6           T1
                   T1
                                         T3          T1
       T3
                                                                    T3                      T4

                                                                                                                                             T4   T6
              T2        T6          T5                 T6
       T5                                      T2                             T5      T2

                             DC MOTORS                                                                     WIRING                                                CONNECTIONS
                                                            COMM OR                   NOT                                           WIRING                         MECHANICAL
                        SHUNT             SERIES            COMPENS                                         POWER
 ARMATURE               FIELD              FIELD                                   CONNECTED                                       TERMINAL
                                                             FIELD



       ARM
                        SHOW 4            SHOW 3             SHOW 2
                        LOOPS             LOOPS              LOOPS                                                                                                  MECHANICAL
                                                                                   CONNECTED               CONTROL                  GROUND                           INTERLOCK
             CONTROL AND POWER CONNECTIONS-600 V OR LESS ACROSS-THE-LINE STARTERS
                                                                                       1                            2 , 4-WIRE                                          3

                                                                                                                   L1, L3 PHASE 1
        LINE MARKINGS                                                                L1, L2                                                                       L1, L2, L3
                                                                                                                   L2, L4 PHASE 2
                                                                                   L1 IS ALWAYS
       GROUND WHEN USED                                                            UNGROUNDED                                                                           L2

        MOTOR RUNNING                               1 ELEMENT                          L1
        OVERCURRENT                                 2 ELEMENT                                                             L1, L4
        UNITS IN                                    3 ELEMENT                                                                                                     L1, L2, L3
        CONTROL CIRCUIT                                                              L1, L2                              L1, L3                                     L1, L2
        CONNECTED TO
       FOR REVERSING                                                                                                     L1, L3                                     L1, L3
       INTERCHANGE LINES


©1999 American Technical Publishers, Inc.
. . . INDUSTRIAL ELECTRICAL SYMBOLS
                                    RESISTORS                                                        CAPACITORS

                                  ADJUSTABLE BY         RHEOSTAT, POT, OR
          FIXED                                                                       FIXED           ADJUSTABLE         POLARIZED
                                    FIXED TAPS           ADJUSTABLE TAP



           RES

                                                                                                                         +           _


           H                          RES
                                                                    RES

  HEATING ELEMENT


         FUSE                     BELL               BUZZER                  HORN,            HALF-WAVE              FULL-WAVE
                                                                          SIREN, ETC.         RECTIFIER              RECTIFIER
     POWER OR
     CONTROL                                                                                                                 AC


                                                                                                                    +                    _
                                                                                                                    DC                   DC




                                                                                                                             AC


    BATTERY                                         IGNITRON                           SEMICONDUCTORS . . .
                       THERMOCOUPLE                   TUBE
                                                                                                     TUNNEL         UNIDIRECTIONAL
                                                                             DIODE                                    BREAKDOWN
                                                                                                      DIODE
                                                    DOT IN TUBE                                                      (ZENER) DIODE
                                                   DENOTES GAS
     +            _




                                                    . . . SEMICONDUCTORS . . .
    BIDIRECTIONAL                                                TRIAC                    SILICON                PROGRAMMABLE
                                  PHOTOSENSITIVE
     BREAKDOWN                                              (BIDIRECTIONAL              CONTROLLED               UNIT - JUNCTION
                                      CELL
        DIODE                                             TRIODE THYRISTOR)              RECTIFIER              TRANSISTOR (PUT)




                                                      . . . SEMICONDUCTORS
                            TRANSISTOR                                                  UNIJUNCTION TRANSISTOR

           PNP BASE                          NPN BASE                              P BASE                           N BASE

                            (C)                               (C)
                                                                                              (B2)                                (B2)
                                                                             (E)                              (E)
           (B)                               (B)




                      (E)                               (E)                                   (B1)                                (B1)




©1999 American Technical Publishers, Inc.

Industrial electrical symbols

  • 1.
    INDUSTRIAL ELECTRICAL SYMBOLS. . . CIRCUIT BREAKER DISCONNECT CIRCUIT CIRCUIT BREAKER CIRCUIT BREAKER W/ THERMAL AND INTERRUPTER WITH THERMAL OL WITH MAGNETIC OL MAGNETIC OL LIMIT SWITCHES PRESSURE AND LIQUID TEMPERATURE- FOOT VACUUM LEVEL ACTUATED FLOW SWITCH NORMALLY NORMALLY SWITCHES (AIR, WATER, ETC.) OPEN CLOSED SWITCHES SWITCH SWITCH NO NO NO NO NO HELD HELD CLOSED OPEN NC NC NC NC NC SYMBOLS FOR STATIC SWITCHING CONTROL DEVICES SPEED (PLUGGING) ANTI-PLUG STATIC SWITCHING CONTROL IS A METHOD OF SWITCHING ELECTRICAL CIRCUITS WITHOUT USE OF CONTACTS, F F F PRIMARILY BY SOLID-STATE DEVICES. USE SYMBOLS SHOWN IN TABLE AND ENCLOSE THEM IN A DIAMOND. INPUT COIL OUTPUT NO LIMIT SWITCH NO LIMIT SWITCH NC R R SELECTOR TWO-POSITION THREE-POSITION TWO-POSITION SELECTOR PUSHBUTTON SELECTOR POSITION J K K J K J L J K L A B A B CONTACTS A1 A1 1 2 BUTTON BUTTON A1 X A1 X FREE DEPRESSED FREE DEPRESSED A2 A2 3 4 A2 X A2 X 1 2 X 3 4 X X X X-CONTACT CLOSED X-CONTACT CLOSED X - CONTACT CLOSED PUSHBUTTONS MOMENTARY CONTACT MAINTAINED CONTACT ILLUMINATED SINGLE DOUBLE MUSHROOM WOBBLE TWO ONE CIRCUIT CIRCUIT HEAD STICK SINGLE DOUBLE CIRCUIT CIRCUIT R NO AND NC NO NC ©1999 American Technical Publishers, Inc.
  • 2.
    . . .INDUSTRIAL ELECTRICAL SYMBOLS . . . CONTACTS OVERLOAD RELAYS TIMED CONTACTS - CONTACT ACTION THERMAL MAGNETIC INSTANT OPERATING RETARDED AFTER COIL IS: WITH BLOWOUT WITHOUT BLOWOUT ENERGIZED DE-ENERGIZED NO NC NO NC NOTC NCTO NOTO NCTC SUPPLEMENTARY CONTACT SYMBOLS SPST NO SPST NC SPDT TERMS SINGLE DOUBLE SINGLE DOUBLE SINGLE DOUBLE BREAK BREAK BREAK BREAK BREAK BREAK SPST SINGLE-POLE, SINGLE-THROW SPDT SINGLE-POLE, DOUBLE-THROW DPST DOUBLE-POLE, DPST, 2NO DPST, 2NC DPDT SINGLE-THROW SINGLE DOUBLE SINGLE DOUBLE SINGLE DOUBLE DPDT BREAK BREAK BREAK BREAK BREAK BREAK DOUBLE-POLE, DOUBLE-THROW NO NORMALLY OPEN NC NORMALLY CLOSED METER (INSTRUMENT) PILOT LIGHTS INDICATE TO INDICATE FUNCTION OF METER OR INSTRUMENT, INDICATE COLOR BY LETTER TYPE BY PLACE SPECIFIED LETTER OR LETTERS WITHIN SYMBOL. LETTER NON PUSH-TO-TEST PUSH-TO-TEST AM or A AMMETER VA VOLTMETER V AH AMPERE HOUR VAR VARMETER A MICROAMMETER VARH VARHOUR METER A R mA MILLAMMETER W WATTMETER AM PF POWER FACTOR WH WATTHOUR METER V VOLTMETER INDUCTORS COILS IRON CORE DUAL-VOLTAGE MAGNET COILS BLOWOUT COIL HIGH-VOLTAGE LOW-VOLTAGE LINK LINKS 1 2 3 4 1 2 3 4 AIR CORE ©1999 American Technical Publishers, Inc.
  • 3.
    . . .INDUSTRIAL ELECTRICAL SYMBOLS . . . TRANSFORMERS AUTO AIR CORE CURRENT CONTROL TRANSFORMER AUTOTRANSFORMER FOR REDUCED- VOLTAGE STARTING SINGLE- DUAL- VOLTAGE VOLTAGE % % 50 50 H3 H2 H1 H2 H1 H4 65 65 80 80 100 100 X2 X1 X2 X1 0 0 AC MOTORS SINGLE- SEPARATE PHASE, SEPARATE WINDING, CONSTANT-TORQUE, THREE-PHASE PHASE TWO-SPEED TWO-SPEED TWO-SPEED T1 T2 HIGH COM LOW T1 T2 T3 T1 T11 T4 T1 T2 T3 T3 T1 T3 T2 T13 T12 T5 T2 T6 VARIABLE-TORQUE, CONSTANT- WYE/DELTA, WYE-CONNECTED, PART WINDING, TWO-SPEED HORSEPOWER, REDUCED- REDUCED-VOLTAGE TWO-SPEED VOLTAGE T4 T4 T1 T2 T3 T7 T8 T9 T5 T6 T1 T1 T3 T1 T3 T3 T4 T4 T6 T2 T6 T5 T6 T5 T2 T5 T2 DC MOTORS WIRING CONNECTIONS COMM OR NOT WIRING MECHANICAL SHUNT SERIES COMPENS POWER ARMATURE FIELD FIELD CONNECTED TERMINAL FIELD ARM SHOW 4 SHOW 3 SHOW 2 LOOPS LOOPS LOOPS MECHANICAL CONNECTED CONTROL GROUND INTERLOCK CONTROL AND POWER CONNECTIONS-600 V OR LESS ACROSS-THE-LINE STARTERS 1 2 , 4-WIRE 3 L1, L3 PHASE 1 LINE MARKINGS L1, L2 L1, L2, L3 L2, L4 PHASE 2 L1 IS ALWAYS GROUND WHEN USED UNGROUNDED L2 MOTOR RUNNING 1 ELEMENT L1 OVERCURRENT 2 ELEMENT L1, L4 UNITS IN 3 ELEMENT L1, L2, L3 CONTROL CIRCUIT L1, L2 L1, L3 L1, L2 CONNECTED TO FOR REVERSING L1, L3 L1, L3 INTERCHANGE LINES ©1999 American Technical Publishers, Inc.
  • 4.
    . . .INDUSTRIAL ELECTRICAL SYMBOLS RESISTORS CAPACITORS ADJUSTABLE BY RHEOSTAT, POT, OR FIXED FIXED ADJUSTABLE POLARIZED FIXED TAPS ADJUSTABLE TAP RES + _ H RES RES HEATING ELEMENT FUSE BELL BUZZER HORN, HALF-WAVE FULL-WAVE SIREN, ETC. RECTIFIER RECTIFIER POWER OR CONTROL AC + _ DC DC AC BATTERY IGNITRON SEMICONDUCTORS . . . THERMOCOUPLE TUBE TUNNEL UNIDIRECTIONAL DIODE BREAKDOWN DIODE DOT IN TUBE (ZENER) DIODE DENOTES GAS + _ . . . SEMICONDUCTORS . . . BIDIRECTIONAL TRIAC SILICON PROGRAMMABLE PHOTOSENSITIVE BREAKDOWN (BIDIRECTIONAL CONTROLLED UNIT - JUNCTION CELL DIODE TRIODE THYRISTOR) RECTIFIER TRANSISTOR (PUT) . . . SEMICONDUCTORS TRANSISTOR UNIJUNCTION TRANSISTOR PNP BASE NPN BASE P BASE N BASE (C) (C) (B2) (B2) (E) (E) (B) (B) (E) (E) (B1) (B1) ©1999 American Technical Publishers, Inc.