Polarity markings:

    Current transformer with instantaneous polarity markings

    Potential transformer with instantaneous polarity markings

Power flow direction:

    One-way

    Either way (not simultaneously)

    Both ways (simultaneously)

Connection symbols:

    2-phase, 3-wire, ungrounded

    2-phase, 3-wire, grounded

    2-phase, 4-wire

    2- phase, 5-wire, grounded

    3- phase, 3-wire, delta or mesh

    3-phase, 3-wire, delta, grounded

    3-phase, 4-wire, delta, ungrounded

    3-phase, 4-wire, delta, grounded

    3-phase, open-delta

    3-phase, open-delta, grounded at the middle point of one winding

    3-phase, broken-delta

    3-phase, wye or star, ungrounded

    3-phase, wye, grounded neutral

    3-phase, 4-wire, ungrounded

    3-phase, zigzag, ungrounded

    3-phase, zigzag, grounded

    3-phase, Scott or T

    6-phase, double-delta

    6-phase, hexagonal (or chordal)

    6-phase, star (or diametrical)

    6-phase, star, with grounded neutral

    6-phase, double zigzag with neutral brought out and grounded

Resistor:

    Resistor (general)

    Tapped resistor

    Resistor with adjustable contact

    Shunt resistor

    Series resistor and path open

    Series resistor and path short-circuited

Capacitor:

    Capacitor (general)

    Polarized capacitor

    Variable capacitor

    Series capacitor and path open

    Series capacitor and path short-circuited

    Shunt capacitor

    Capacitor bushing for circuit breaker or transformer

    Capacitor-bushing potential device

    Coupling capacitor potential device

Battery:

    Battery (general)

    Battery with one cell

    Battery with multicell

Transmission path (conductor, cable wire):

    Bus bar, with connection

    Conductor or path

    2 conductors or paths

    3 conductors or paths

    n conductors or paths

    Crossing of two conductors or paths not connected

    Junction

    Junction of connected paths

    Shielded single conductor

    Shielded 5-conductor cable

    Shielded 2-conductor cable with conductors separated on the diagram for convenience

    3-conductor cable

Grouping of leads:

    General

    Interrupted

Transmission and distribution lines:

    Telephone line

    Cable (or line) underground

    Submarine line

    Overhead line

    Loaded line

Ground:

    Ground (general)

Switch:

    Single-throw switch (disconnect switch)

    Double-throw switch

    Knife switch

Connector:

    Female contact

    Male contact

    Separable connectors

Operating coil:

    Operating coil (general), e.g., reactor

Transformer:

    Transformer (general)

    Adjustable mutual inductor (constant-current transformer)

    Single-phase transformer with taps

    Single-phase autotransformer

    Adjustable

    Step-voltage regulator or load-ratio control autotransformer

    Step-voltage regulator

    Load-ratio control autotransformer

    Load-ratio control transformer with taps

    Single-phase induction voltage regulator

    Triplex induction voltage regulator

    3-phase induction voltage regulator

    1-phase, 2-winding transformer

    3-phase bank of 1-phase, 2-winding transformers with wye–delta connections

Polyphase transformer:

    Polyphase transformer (general)

    1-phase, 3-winding transformer

Current transformer:

    Current transformer (general)

    Bushing-type current transformer

Potential transformers:

    Potential transformer (general)

    Outdoor metering device

    Linear coupler

Fuse:

    Fuse (general)

    Fuse (supply side indicated by a thick line)

    Isolating fuse switch (HV primary fuse cutout) dry

    HV primary fuse cutout, oil

    Isolating fuse switch for onload switching

    Current limiter (for power cable)

    Lightning arrester

    Horn gap

    Multigap (general)

Circuit breaker:

    Circuit breaker, air (for dc or ac rated at 1.5 kV or less)

    Network protector

    HV circuit breaker (for ac rated at above 1.5 kV)

    Circuit breaker with thermal-overload device

    Circuit breaker with magnetic thermal-overload device

    Circuit breaker, drawout type

Rotating machine:

    Generator (general)

    Generator, dc

    Generator, ac

    Generator, synchronous

    Motor (general)

    Motor, dc

    Motor, ac

    Motor, synchronous