Comprehensive Guide to Electrical Symbols

Thread Content

This post was last edited by yunrun on 2016-11-18 at 17:45. Electrical graphic symbols and textual symbols facilitate users in reviewing and designing electrical drawings. Changhui Instrument Manufacturing Co., Ltd. has compiled the most common electrical symbols used in electrical drawing design, in accordance with the latest standards and IEC standards, to share with everyone. Functional documents use electrical graphic symbols, DC graphic symbols, AC graphic symbols, positive pole, negative pole. DC text symbol: DC; AC text symbol: AC. Changhui Instruments: http%3a//yunrun%2ecom%2cn. Neutral wire (middle wire), middle wire, grounding, flexible connection, stranded wire, shielded wire, wires in cables, terminals. Stranded wire text symbol: WD; terminal block text symbol: XT. Socket, female contact (connector); plug, male contact (connector); plugs and sockets, connecting pieces. Socket text symbol: XS; plug text symbol: XP; connecting piece text symbol: XB. Disconnected connecting piece. Resistor, varistor, distributor, resistor with current and voltage division terminals. Connecting piece text symbol: XB; resistor text symbol: RA ； R (old) Symbol for varistors: RV. Symbol for start-up resistors (shunt resistors): RS. Electric heating elements, capacitors, polarized capacitors, diodes. Symbol for electric heating elements: EE. Symbol for capacitors: CA ； C (old) Diode symbol: VD – Voltage-regulating diode, unidirectional breakdown diode. Triode thyristor. PNP semiconductor transistor. PNP semiconductor transistor with the collector integrated into the casing. Zener diode symbol: VV. BJT symbol: VT. PNP semiconductor transistor symbol: V. Bidirectional triode thyristor. Inductors, coils, windings, chokes. Rectifiers, inverters. Primary cells, battery packs. Bidirectional thyristor symbol: VS. Choke coil symbol: RA ； LC (old) Inverter text symbol: TB ； UV (old) battery symbol: GB; excitation coil symbol: RA ； LE (old) modulator, mixer – symbolic notation: UM. Power generator, converted power generator; photovoltaic generator; DC/DC inverter; rectifier. Symbolic notation for power generator: GF ； GS (old) rectifier textual symbol: TB ； U (old) Isolating switch: A two-way isolating switch with an intermediate off position. Load switch (load isolating switch): A load switch with an automatic release function. Symbol for isolating switch: QB ； QS (old) isolating switch symbolic notation: QB ； QS (old) load switch symbolic notation: QB ； QS (old) load switch symbolic notation: QB ； QS (old) circuit breaker, fuse-type switch, fuse-type isolator, fuse-type load switch; Circuit breaker symbol: QA ； QF (old) fuse-type switch symbolic notation: QA ； QKF (old) fuse-type isolating switch symbolic designation: QA ； QKF (old) contactor, the normally closed contact of a contactor, the normally open contact of a contactor, static switch, static (semiconductor) contactor; symbolic designation for contactor contacts: QA ； KM (old) contactor contact letter symbol: QA ； KM (old) fuse, fuse with link (impact fuse), spark gap, lightning arrester. Fuse symbolic designation: FA ； FU (old) fuse textual symbol: FA ； FU (old) lightning arrester symbolic notation: F – General symbol for a switch; normally open contact. General symbol for a switch; normally closed contact. Switching contact that closes first and then opens. Bidirectional switching contact that is open in the middle. Symbolic notation for relay contacts: KA. Symbolic notation for contactor contacts: KM. Switching contact that opens first and then closes. Normally open contact that closes earlier than other contacts. Normally open contact that closes later than other contacts. Normally closed contact that releases later than other contacts. Normally closed contact that releases earlier than other contacts. Normally open contact that closes after a delay when activated. Normally open contact that opens after a delay when de-activated. Normally closed contact that closes after a delay when activated. Symbolic notation for time relays: KT. Symbolic notation for time relays: KT. Symbolic notation for time relays: KT. Normally closed contact that closes after a delay when de-activated. Normally open contact that closes after a delay when activated and opens after a delay when de-activated. Manual operation switch. A manual three-pole switch (type 1). Symbolic notation for time relays: KT. Symbolic notation for time relays: KT. Contact that closes automatically and has a self-resetting function. Rotary switch with normally open contacts but no automatic reset function. Mushroom-shaped button switch with normally open contacts and self-resetting function. Button switch operated by key, with normally open contacts. Symbolic notation for test buttons: SE. Symbolic notation for switching switches: SA. Symbolic notation for buttons: SB. Symbolic notation for buttons: SB. Symbolic notation for reset buttons: SR. Symbolic notation for buttons: SB. Button switch with normally open contacts to prevent incorrect operation. Position switch, normally open contact. Position switch, normally closed contact. Thermal switch, normally open contact. Symbolic notation for buttons: SB. Symbolic notation for position switches: SQ. Symbolic notation for position switches: SQ. Thermal switch, normally closed contact. Thermal automatic switch, normally closed contact. Thermal relay, normally closed contact. Level controller, normally open contact. Symbolic notation for thermal relays: BB ； Coil of FR (old) relay – a combined representation of an operator with two independent windings. Coil of a relay that operates with delay in closing. Coil of a relay that releases slowly. Symbol for a time relay: KT. Coils of relays that operate with immediate closing and slow release. Coil of a mechanically latching relay. Driving element of an electronic relay. General symbol for a static relay; normally open contacts. Under-voltage relay, with a setting range of 50–80 V; reset ratio of 130%. Current relay (with maximum and minimum current settings). Gas protector. Automatic reclosing relay. Symbol for a current relay: Voltmeter. Reactive current meter. Indicator showing the maximum demand during excitation. Reactive power meter. Symbol for a voltmeter: PV. Symbol for a reactive current meter: FAR. Symbol for a reactive power meter: PR. Power factor meter. Phase meter. Frequency meter. Synchronization indicator. Symbol for a power factor meter: PPF. Symbol for a phase meter: PPA. Symbol for a frequency meter: PF. Galvanometer. Tachometer. Recording power meter. Thermometers, high-temperature meters. Combined recording power meter and reactive power meter. Oscilloscope. Electricity meter. Multi-rate electricity meter. Meter for measuring excess consumption. Transmitter-equipped electricity meter. Electricity meter with maximum demand recorder. Reactive electricity meter. Symbol for a reactive electricity meter: PJR. Electricity meter with maximum demand indicator. Thermocouple (type 1). Thermocouple (type 2). Signal converter. Maximum demand meter (load monitor); symbol: PM. Symbol for a thermocouple: TC. Clock with contacts. Master clock. Sub-clocks, clocks. Signal lights. Symbol for signal lights: HG (green) ； HR (red) flashing signal lights, electric horns, electric bells, alarms, buzzers. Electrical symbols for motors/generators: Generator, synchronous generator; Motor, synchronous motor. Symbol for generator: G; Symbol for synchronous generator: GS; Symbol for motor: M; Symbol for synchronous motor: MS. Three-phase wound induction motors, three-phase squirrel-cage induction motors, single-phase squirrel-cage induction motors with phase-separated winding leads. Symbol for squirrel-cage motor: MC. Symbols for transformers: Two-winding transformer, two-winding transformer (type 2), single-phase two-winding transformer with shielding between windings, transformer with a center tap on one winding. Symbol for transformer: T. Transformer with a center tap on one winding, single-phase two-winding transformer with shielding between windings, three-phase transformer in star-delta connection, three-phase transformer in star-delta connection, transformer with four taps in star-star connection, three-phase transformer composed of single-phase transformers in star-delta connection, three-phase transformer with on-load tap changer, three-phase transformer in star-star-star connection, autotransformer, single-phase autotransformer, three-phase autotransformers in star connection, adjustable-voltage single-phase autotransformer, three-phase induction voltage regulator. Symbols for current and voltage transformers: Current-limiting coil, voltage transformer, three-winding voltage transformer, current transformer with two cores and two secondary windings. Symbol for current transformer: TA. Current transformer with one core and two secondary windings, three current transformers, pulse transformer or current transformer with three primary conductors, transformer with two cores, each core having one or two current transformers (two cores for phases 1 and 3, each core with one secondary winding, three current transformers) ； Three secondary leads) Two current transformers in the secondary winding. Location files represented using electrical schematic symbols. Power plants that are in operation or not specified. Thermal power plants that are planned (designed) or not specified. Substations and distribution stations that are planned (designed) or not specified. Lines and connections; underground lines – lines with connection points buried underground. Grounding electrodes; grounding wires. Underwater (seabed) lines; overhead lines; pipeline lines (with indication of the number of pipe holes). Cable tray lines; cable trench lines; through-hole lines. Neutral wire; protective wire. http://yunrun.com.cn/upload/201607/22/201607221324235776.png http://yunrun.com.cn/upload/201607/22/201607221324237651.png http://yunrun.com.cn/upload/201607/22/201607221324239057.png http://yunrun.com.cn/upload/201607/22/201607221324240307.png Protective grounding wire; shared wire for neutral and protective wires; three-phase wiring with protective and neutral wires. Power distribution upward; power distribution downward. Single connection leading to a harness; vertical passage through the wiring. Harness (Method 1); Harness (Method 2). Single-wire connection; multi-wire connection. Lightning protection strips, wires, and nets; lightning rods. Objects (codes or text to be filled in within the outline). Electrical cabinets (types indicated nearby). Power distribution centers; power distribution boxes; emergency power distribution boxes; lighting distribution boxes; emergency lighting distribution boxes. Boxes; junction boxes. User side; generator starters; control-starters; star-delta starters; reversible motors; direct online contactor starters; autotransformer starters; control-starters with controllable rectifiers. Multiple power sockets; power sockets with protective contacts; single-phase power sockets; three-phase power sockets; single-phase recessed power sockets; three-phase recessed power sockets; single-phase explosion-proof power sockets; three-phase explosion-proof power sockets; single-phase sealed power sockets; three-phase sealed power sockets; power sockets with guards; power sockets with single-pole switches; power sockets with interlocked switches; sockets with isolation transformers. General symbol for switches; recessed switches; switches with indicators; single-limit switches; multi-pole single-switches; two-control single-switches; intermediate switches, equivalent circuit diagrams. Dimmers; buttons; button boxes consisting of two button units; button boxes consisting of three button units. Explosion-proof buttons; sealed buttons; buttons with lights. Time-limited devices, timers; timed switches; key switches, surveillance system devices. Floodlights; auxiliary equipment for gas discharge lamps; emergency lighting on dedicated circuits; emergency lighting with its own power source. Fault lights, hazard signals, red flashing lights. Water heaters; electric fans; clocks, clock recorders; electric locks; safety isolation transformers; electric valves; solenoid valves; fan coils; window air conditioners. Fuse boxes; knife switch boxes; circuit breaker boxes, busbar slot boxes; terminal boxes. Direct connection areas with fixed branch circuits equipped with device boxes; direct sections with fixed branches and sockets having protective contacts