CT
Current transformer
A current-measurement transformer used with metering and protection equipment.
SLD / Schematic
Browse by subject
Metering & protection
Instrument transformers, measurement, protection relays and device-function numbers. Explore 237 references, with original explanations and public primary sources.
VT / PT
Voltage transformer
A transformer providing a voltage signal for metering or protection.
SLD / Schematic
25
Synchronism check
Checks documented synchronising conditions before a permitted connection.
Protection functions
27
Undervoltage
A function responding to voltage below its configured operating criteria.
Protection functions
32
Directional power
A function responding to power with a specified direction and operating condition.
Protection functions
46
Current unbalance / negative sequence
A current phase-balance or reverse-phase function used in documented protection applications.
Protection functions
49
Thermal protection
A thermal protection function for a documented machine or transformer application.
Protection functions
50
Instantaneous overcurrent
An overcurrent function without an intentional operating time delay in its instantaneous application.
Protection functions
51
Time overcurrent
An overcurrent function with a documented time characteristic.
Protection functions
59
Overvoltage
A function responding to voltage above its configured operating criteria.
Protection functions
67
Directional overcurrent
An overcurrent function with a documented direction criterion.
Protection functions
79
AC autoreclosing
A function coordinating a documented automatic reclosing sequence.
Protection functions
81
Frequency protection
A function responding to a documented frequency condition.
Protection functions
86
Lockout
A lockout function or device with the documented reset and blocking behaviour.
Protection functions
87
Differential protection
A function comparing documented electrical quantities across a protection zone.
Protection functions
1
Master element
Starts or enables the principal operating sequence of a machine or power-system unit.
Protection functions
2
Time-delay starting or closing relay
Introduces a deliberate interval before a starting or closing operation is permitted.
Protection functions
3
Checking or interlocking relay
Checks a required equipment state before the operating sequence proceeds.
Protection functions
4
Master contactor
Switches the main control or operating circuit under the unit's master command.
Protection functions
5
Stopping device
Initiates a machine or unit shutdown by removing the relevant operating permission.
Protection functions
6
Starting circuit breaker
Connects a machine to the electrical supply used during starting.
Protection functions
7
Rate-of-change relay
Responds to how quickly a monitored quantity changes rather than only its absolute magnitude.
Protection functions
8
Control power disconnecting device
Isolates the supply feeding a control circuit or control-power bus.
Protection functions
9
Reversing device
Changes the operating connection to reverse the direction of a machine or power circuit.
Protection functions
10
Unit sequence switch
Selects or determines the order in which multiple units enter an operating sequence.
Protection functions
11
Multifunction device
Identifies a device that performs several separately described protection or control functions.
Protection functions
12
Overspeed device
Responds when machine speed exceeds the documented operating criterion.
Protection functions
13
Synchronous-speed device
Recognises a speed condition associated with synchronism during a machine sequence.
Protection functions
14
Underspeed device
Responds to machine speed below the required operating level.
Protection functions
15
Speed or frequency matching device
Adjusts or supervises the difference between two speed or frequency references.
Protection functions
16
Data communications device
Identifies equipment carrying data between control, protection or monitoring devices.
Protection functions
17
Shunting or discharge switch
Changes a circuit connection to bypass a component or provide a discharge path.
Protection functions
18
Accelerating or decelerating device
Controls a machine action that changes its operating speed during a sequence.
Protection functions
19
Starting-to-running transition contactor
Changes the machine connection from its starting arrangement to its running arrangement.
Protection functions
20
Electrically operated valve
Commands a valve through an electrical actuator or solenoid.
Protection functions
21
Distance protection
Uses measured voltage and current to assess an electrical distance or impedance characteristic.
Protection functions
22
Equalizer circuit breaker
Switches an equalising connection used in a machine or generator arrangement.
Protection functions
23
Temperature control device
Controls heating, cooling or another process action using a temperature input.
Protection functions
24
Overexcitation protection
Supervises the voltage-to-frequency relationship associated with magnetic overexcitation.
Protection functions
26
Apparatus thermal device
Responds to the temperature of equipment or a monitored part of that equipment.
Protection functions
28
Flame detector
Provides electrical indication that combustion flame is present or absent.
Protection functions
29
Isolating contactor
Provides a contactor-operated disconnection within a machine or power circuit.
Protection functions
30
Annunciator relay
Operates an indication system that presents a detected condition to the operator.
Protection functions
31
Separate excitation device
Connects or controls a separately supplied excitation arrangement for a machine.
Protection functions
33
Position switch
Changes an electrical indication when a mechanism reaches a defined physical position.
Protection functions
34
Master sequence device
Coordinates the steps of a machine or switching sequence.
Protection functions
35
Brush-operating or slip-ring short-circuiting device
Changes the brush or slip-ring arrangement as part of a wound-rotor machine sequence.
Protection functions
36
Polarity device
Supervises or establishes a required electrical polarity condition.
Protection functions
37
Undercurrent or underpower protection
Recognises a current or power level below the documented minimum operating criterion.
Protection functions
38
Bearing protective device
Supervises an abnormal condition at a machine bearing, often using temperature or mechanical sensing.
Protection functions
39
Mechanical condition monitor
Converts a monitored mechanical condition into an electrical alarm or protection signal.
Protection functions
40
Field or loss-of-excitation protection
Detects an abnormal machine excitation condition using the implementation's field or electrical measurements.
Protection functions
41
Field circuit breaker
Applies or removes the electrical connection to a machine field circuit.
Protection functions
42
Running circuit breaker
Connects a machine to the supply or connection used for normal running.
Protection functions
43
Manual transfer or selector device
Selects an operating circuit, control source or mode through a manual action.
Protection functions
44
Unit sequence starting relay
Starts the next unit or operating step when the documented sequence condition is met.
Protection functions
45
Atmospheric condition monitor
Reports an ambient atmospheric condition relevant to equipment operation.
Protection functions
47
Phase-sequence or voltage-balance protection
Supervises phase order or voltage imbalance using the selected device's voltage inputs.
Protection functions
48
Incomplete-sequence relay
Detects that an operating or starting sequence has not completed as required.
Protection functions
53
Exciter or DC generator relay
Supervises an exciter or DC generator condition in a machine control arrangement.
Protection functions
54
Turning-gear engaging device
Controls engagement of the turning gear used to rotate a large machine at low speed.
Protection functions
55
Power factor protection
Supervises power factor according to the selected relay's electrical measurement method.
Protection functions
56
Field application relay
Initiates application of excitation at the appropriate step of a machine starting sequence.
Protection functions
57
Short-circuiting or grounding device
Makes a defined short-circuit or earth connection for the purpose shown in the machine or apparatus scheme.
Protection functions
58
Rectification failure relay
Detects failure or abnormal operation in a rectifier arrangement.
Protection functions
60
Voltage or current balance relay
Compares related measured circuits or quantities to detect an abnormal imbalance.
Protection functions
61
Density switch or sensor
Monitors the density of a medium used by electrical equipment.
Protection functions
62
Time-delay stopping or opening relay
Introduces a documented delay in a stopping or opening operation.
Protection functions
63
Pressure switch or relay
Provides an electrical response to a gas, liquid or other pressure condition.
Protection functions
64
Ground detector protection
Identifies an earth or ground fault using the circuit arrangement specified for the device.
Protection functions
65
Governor
Regulates the operating speed or mechanical input of a generating or rotating unit.
Protection functions
66
Notching or jogging device
Controls limited machine movements or, in modern motor relays, supervises the allowed starting duty.
Protection functions
68
Blocking or out-of-step supervision
Restrains or coordinates another protection action under the specified system condition.
Protection functions
69
Permissive control device
Permits or prevents an equipment operation according to a selected control condition.
Protection functions
70
Rheostat
Provides adjustable resistance in a control, excitation or machine circuit.
Protection functions
71
Level switch or relay
Signals a defined level condition in the monitored equipment.
Protection functions
72
DC circuit breaker
Interrupts or switches a direct-current power circuit using a breaker selected for DC duty.
Protection functions
73
Load-resistor contactor
Switches a resistor used to impose, remove or change electrical load in a machine arrangement.
Protection functions
74
Alarm relay
Provides an electrical alarm output for a documented monitored condition.
Protection functions
75
Position-changing mechanism
Moves an apparatus between defined physical positions.
Protection functions
76
DC overcurrent relay
Supervises excessive current in a direct-current circuit.
Protection functions
77
Telemetering device
Transmits a measured quantity from its local measurement point to a remote indication or monitoring system.
Protection functions
78
Phase-angle or out-of-step protection
Supervises the angular relationship or loss of synchronism of an electrical system or machine.
Protection functions
80
Flow switch or relay
Reports a flow condition in a monitored gas or liquid circuit.
Protection functions
82
DC load-measuring reclosing relay
Supervises a DC load condition as part of a documented reclosing arrangement.
Protection functions
83
Automatic selective control or transfer relay
Automatically selects between control circuits or operating sources under defined conditions.
Protection functions
84
Operating mechanism
Provides the motive action that operates electrical apparatus.
Protection functions
85
Pilot or carrier receiver relay
Receives a communication-assisted protection signal used in a pilot or carrier scheme.
Protection functions
88
Auxiliary motor or motor-generator
Identifies a motor or motor-generator serving an auxiliary equipment function.
Protection functions
90
Regulating device
Adjusts equipment to maintain the controlled electrical or operating quantity.
Protection functions
91
Voltage directional relay
Uses a voltage relationship with a defined direction criterion in a specialist protection or control scheme.
Protection functions
92
Voltage and power directional relay
Combines voltage and power directional criteria in the specified control or protection arrangement.
Protection functions
93
Field-changing contactor
Changes the machine excitation connection or arrangement as part of a controlled field sequence.
Protection functions
94
Tripping or trip-free relay
Initiates a tripping action or provides the trip-related logic described in the scheme.
Protection functions
21P
Phase distance protection
Evaluates an impedance characteristic for phase-fault loops on the protected circuit.
Protection functions
21G
Ground distance protection
Evaluates a distance characteristic for a phase-to-earth fault loop.
Protection functions
21YN
Admittance-based earth-fault protection
Uses earth-fault voltage and current relationships to assess an admittance-based directional criterion.
Protection functions
27A
Auxiliary-input undervoltage protection
Supervises low voltage using the auxiliary voltage input identified by the selected relay.
Protection functions
27M
Main-input undervoltage protection
Supervises low voltage using the relay's main voltage measurement inputs.
Protection functions
27Q
Reactive-power undervoltage protection
Combines a reactive-power criterion with undervoltage supervision in the cited interconnection application.
Protection functions
27T
Low-voltage ride-through supervision
Supervises a voltage-time ride-through criterion used in a generator or interconnection application.
Protection functions
32N
Wattmetric earth-fault protection
Uses residual voltage and current to assess earth-fault power in the documented neutral-system application.
Protection functions
32V
Directional reactive-power protection
Supervises forward or reverse reactive power using the selected relay's power-direction convention.
Protection functions
32R
Reverse-power protection
Detects active power flowing opposite to the defined generator or circuit direction.
Protection functions
32U
Underpower protection
Supervises active power below the documented operating criterion.
Protection functions
46G
Generator current-unbalance protection
Supervises generator current imbalance using the manufacturer's machine protection implementation.
Protection functions
46PD
Phase-discontinuity protection
Uses current-sequence relationships to detect a phase-discontinuity condition.
Protection functions
49R
RTD-based thermal protection
Uses resistance-temperature-detector measurements for an equipment thermal protection function.
Protection functions
49M
Motor thermal-model protection
Estimates motor thermal duty using the selected relay's motor thermal model.
Protection functions
50P
Instantaneous phase overcurrent
Supervises phase-current magnitude for the instantaneous overcurrent element.
Protection functions
50N
Instantaneous neutral overcurrent
Supervises the neutral or residual-current quantity identified by the protection scheme.
Protection functions
50G
Instantaneous ground overcurrent
Supervises the ground-current input or ground-fault quantity identified by the selected relay.
Protection functions
50Q
Instantaneous negative-sequence overcurrent
Supervises negative-sequence current for an instantaneous overcurrent element.
Protection functions
50R
Calculated residual instantaneous overcurrent
Supervises an instantaneous residual-current element calculated from phase-current measurements in the cited Eaton family.
Protection functions
50X
Measured ground instantaneous overcurrent
Supervises the instantaneous element using a separately measured ground or neutral input in the cited Eaton family.
Protection functions
50BF
Circuit-breaker failure protection
Initiates the documented backup action when a breaker does not clear the monitored condition after a trip initiation.
Protection functions
50J
Motor jam or stall protection
Supervises a motor current condition associated with a jam or stall in the cited relay application.
Protection functions
51P
Time phase-overcurrent protection
Supervises phase overcurrent using the selected time-current characteristic or intentional operating delay.
Protection functions
51N
Time neutral-overcurrent protection
Supervises neutral or residual overcurrent with the configured timing characteristic.
Protection functions
51G
Time ground-overcurrent protection
Supervises ground-current overcurrent with the timing defined by the selected relay and scheme.
Protection functions
51Q
Time negative-sequence overcurrent
Supervises negative-sequence current using a time-dependent operating criterion.
Protection functions
51R
Calculated residual time-overcurrent
Applies time-overcurrent protection to the calculated residual-current input in the cited Eaton family.
Protection functions
51X
Measured ground time-overcurrent
Applies time-overcurrent protection to a separately measured ground or neutral input in the cited Eaton family.
Protection functions
51V
Voltage-dependent overcurrent
Changes overcurrent operation according to the measured voltage using the relay's documented voltage-dependent method.
Protection functions
55A
Apparent power-factor supervision
Supervises the apparent power-factor quantity defined in the cited relay family.
Protection functions
55D
Displacement power-factor supervision
Supervises displacement power factor as defined by the relay's fundamental-frequency measurements.
Protection functions
59N
Residual or neutral overvoltage
Supervises a residual or neutral voltage used by the selected earth-fault or neutral-displacement scheme.
Protection functions
59Q
Negative-sequence overvoltage
Supervises the negative-sequence component derived from three-phase voltage measurements.
Protection functions
59A
Auxiliary-input overvoltage
Supervises high voltage on the auxiliary measurement input in the cited Eaton family.
Protection functions
59M
Main-input overvoltage
Supervises high voltage using the main three-phase inputs in the cited Eaton family.
Protection functions
64F
Field ground-fault protection
Detects an earth fault in a machine field circuit using the selected field-ground detection arrangement.
Protection functions
64G
Stator ground-fault protection
Supervises generator stator earth faults using the selected stator-ground protection method.
Protection functions
67P
Directional phase-overcurrent
Combines phase-current overcurrent operation with the scheme's direction criterion.
Protection functions
67N
Directional neutral-overcurrent
Supervises neutral or residual overcurrent with a documented directional criterion.
Protection functions
67G
Directional ground-overcurrent
Supervises a ground-current quantity with direction determined by the selected relay's polarising method.
Protection functions
67Q
Directional negative-sequence overcurrent
Uses negative-sequence quantities to supervise overcurrent operation in a defined direction.
Protection functions
67R
Calculated residual directional overcurrent
Applies directional overcurrent to calculated residual current in the cited Eaton application.
Protection functions
67X
Measured ground directional overcurrent
Applies directional supervision to the separately measured ground or neutral current element in the cited Eaton family.
Protection functions
67YN
Multifrequency admittance earth-fault protection
Assesses earth-fault behaviour using the manufacturer's multifrequency admittance-based method.
Protection functions
67NIEF
Transient or intermittent earth-fault protection
Supervises transient or intermittent earth-fault behaviour in the documented feeder application.
Protection functions
74TCM
Trip-coil monitoring
Monitors the electrical integrity of a documented breaker trip-coil circuit.
Protection functions
78VS
Voltage vector-shift protection
Supervises an abrupt change in the measured voltage phase angle using the selected relay's vector-shift method.
Protection functions
81U
Underfrequency protection
Supervises frequency below the defined operating criterion.
Protection functions
81O
Overfrequency protection
Supervises frequency above the defined operating criterion.
Protection functions
81R
Rate-of-change-of-frequency protection
Supervises the rate at which measured electrical frequency changes.
Protection functions
87T
Transformer differential protection
Compares currents associated with a transformer protection zone using the selected relay's differential method.
Protection functions
87B
Busbar differential protection
Compares currents at the boundaries of a busbar protection zone.
Protection functions
87G
Generator differential protection
Compares current measurements bounding the selected generator differential zone.
Protection functions
87M
Motor differential protection
Compares current measurements defining a motor differential protection zone.
Protection functions
87L
Line current differential protection
Compares current information from the terminals of a protected line using a communication-assisted differential scheme.
Protection functions
87N
Neutral differential protection
Identifies a differential scheme involving neutral or residual-current quantities as defined by the equipment documentation.
Protection functions
87Q
Negative-sequence differential protection
Compares negative-sequence current information across a differential protection zone.
Protection functions
87R
Restrained current differential protection
Uses a differential operating quantity with restraint in the cited transformer-relay application.
Protection functions
87H
Unrestrained high-set differential protection
Provides the documented high-set or unrestrained differential element in the cited relay family.
Protection functions
87GD
Restricted ground differential protection
Compares ground-fault-related currents for the restricted zone defined by the cited relay application.
Protection functions
CT 2SEC
Current transformer with two secondaries
A CT with two secondary windings supplies two documented secondary circuits.
SLD / Schematic
CT TAP
Tapped-secondary current transformer
A tapped CT secondary provides alternative documented transformation ratios through different terminal combinations.
SLD / Schematic
CT PRI
Current transformer with primary conductor indication
This CT representation explicitly identifies the primary conductor passing through the measurement location.
SLD / Schematic
CBCT
Core-balance current transformer
A core-balance CT measures residual current from the net magnetic effect of conductors passing through its window.
SLD / Schematic
CT RES
Residual connection of phase CTs
A residual CT connection combines secondary currents from phase CTs to obtain a residual-current input.
SLD / Schematic
TC
Thermocouple
A thermocouple produces a temperature-dependent voltage associated with its dissimilar-metal junction system.
Schematic
RTD
Resistance temperature detector
An RTD is a temperature sensor whose resistance changes with temperature.
Schematic
V
Voltmeter
A voltmeter indicates electrical potential difference between its measurement inputs.
SLD / Schematic
A
Ammeter
An ammeter indicates current from a direct or instrument-transformed measurement circuit.
SLD / Schematic
PF
Power-factor meter
A power-factor meter indicates the relationship between real and apparent power according to the instrument's measurement method.
SLD / Schematic
PHASE
Phase-angle meter
A phase-angle meter indicates the phase relationship between documented signals.
SLD / Schematic
Hz
Frequency meter
A frequency meter indicates the frequency of its measured input.
SLD / Schematic
TEMP
Temperature indicator
A temperature indicator displays the temperature derived from its specified sensor or input.
SLD / Schematic
RPM
Tachometer
A tachometer indicates rotational speed from its documented sensor or electrical input.
SLD / Schematic
HOURS
Running-hours meter
A running-hours meter accumulates elapsed time while its specified enabling condition is active.
SLD / Schematic
Ah
Ampere-hour meter
An ampere-hour meter integrates current over time for a documented measurement purpose.
SLD / Schematic
W REC
Recording wattmeter
A recording wattmeter measures active power and records it according to the specified instrument.
SLD / Schematic
var
Reactive-power meter
A reactive-power meter indicates reactive power using the instrument's documented voltage and current inputs.
SLD / Schematic
SYNC SCOPE
Synchronoscope
A synchronoscope indicates the phase relationship and relative frequency behaviour of two AC sources.
SLD / Schematic
kW
Active-power indicator
An active-power indicator displays real power derived from its specified measurement inputs.
SLD / Schematic
DELTA V
Differential voltmeter
A differential voltmeter indicates a difference between documented voltage inputs.
SLD / Schematic
kWh
Active-energy meter
An active-energy meter accumulates active power over time.
SLD / Schematic
kvarh
Reactive-energy meter
A reactive-energy meter accumulates reactive power over time according to the specified register convention.
SLD / Schematic
I HIGH
Maximum-current monitoring relay
A maximum-current relay changes its output when the measured current meets a configured high-current condition.
SLD / Schematic
I LOW
Minimum-current monitoring relay
A minimum-current relay operates according to a configured low-current condition.
SLD / Schematic
I WINDOW
Current window monitoring relay
A current-window relay supervises both minimum and maximum current conditions.
SLD / Schematic
I DIFF
Differential-current measuring relay
A differential-current relay responds to the relationship between specified current inputs.
SLD / Schematic
U RES
Residual-voltage monitoring relay
A residual-voltage relay responds to the specified residual-voltage measurement.
SLD / Schematic
U LOSS
Loss-of-voltage monitoring relay
A loss-of-voltage relay changes its output for a documented absence-of-voltage condition.
SLD / Schematic
PH LOSS
Phase-loss monitoring relay
A phase-loss relay supervises the presence of the specified phases in a three-phase system.
SLD / Schematic
f MON
Frequency monitoring relay
A frequency relay issues a documented output for a configured frequency condition.
SLD / Schematic
P LOW
Minimum active-power relay
A minimum active-power relay operates according to a configured low active-power condition.
SLD / Schematic
ISO I-I
Analog current signal isolator
A current signal isolator transfers a documented analog current input to an output while providing the specified electrical separation.
SLD / Schematic
TEMP TX
Temperature measuring transducer
A temperature transducer converts a documented temperature-sensor input into an instrument signal.
SLD / Schematic
GA
Protection relay panel
A relay panel houses protection, control, test and terminal equipment for defined circuits.
GA objects
GA
Panel power meter
A panel power meter measures the specified electrical quantities through its input interfaces.
GA objects
GA
Energy submeter
An energy submeter measures consumption for a specified circuit or group of loads.
GA objects
GA
Window current transformer
A window CT surrounds a conductor or busbar to provide the specified current measurement.
GA objects
GA
Split-core current transformer
A split-core CT can be assembled around the specified existing conductor.
GA objects
VT
Voltage transformer assembly
A voltage-transformer assembly provides the specified voltage measurement interface.
GA objects
DC
Battery current shunt
A current shunt provides a specified DC current-measurement interface.
GA objects
MiCOM protection relays
Schneider Electric MiCOM protection relays
Schneider Electric MiCOM protection relays is a protection relay ied product family referenced for electrical equipment layout.
GA objects
PowerLogic PM5000
Schneider Electric PowerLogic PM5000
Schneider Electric PowerLogic PM5000 is a panel power meter product family referenced for electrical equipment layout.
GA objects
PowerLogic PM8000
Schneider Electric PowerLogic PM8000
Schneider Electric PowerLogic PM8000 is a panel power meter product family referenced for electrical equipment layout.
GA objects
PowerLogic P5 protection relays
Schneider Electric PowerLogic P5 protection relays
Schneider Electric PowerLogic P5 protection relays is a protection relay ied product family referenced for electrical equipment layout.
GA objects
GA
Protection relay IED
A protection relay IED implements the selected measurement, protection and control functions.
GA objects
SmartShunt
Victron Energy SmartShunt
Victron Energy SmartShunt is a battery current shunt product family referenced for electrical equipment layout.
GA objects
PQM
Power quality meter
A measuring device used to monitor electrical quantities and documented power-quality events or waveform characteristics.
GA objects
CVT / CCVT
Capacitor voltage transformer
An instrument transformer using a capacitive voltage divider and an electromagnetic unit to supply documented voltage measurement or protection signals.
SLD / Schematic
CT
ANSI/IEEE current transformer symbol
IEEE-oriented graphical reference for current transformer, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
CT 2SEC
ANSI/IEEE current transformer with two secondaries symbol
IEEE-oriented graphical reference for current transformer with two secondaries, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
CT TAP
ANSI/IEEE tapped-secondary current transformer symbol
IEEE-oriented graphical reference for tapped-secondary current transformer, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
VT / PT
ANSI/IEEE voltage transformer symbol
IEEE-oriented graphical reference for voltage transformer, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
V
ANSI/IEEE voltmeter symbol
IEEE-oriented graphical reference for voltmeter, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
A
ANSI/IEEE ammeter symbol
IEEE-oriented graphical reference for ammeter, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
PF
ANSI/IEEE power-factor meter symbol
IEEE-oriented graphical reference for power-factor meter, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
Hz
ANSI/IEEE frequency meter symbol
IEEE-oriented graphical reference for frequency meter, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
W REC
ANSI/IEEE recording wattmeter symbol
IEEE-oriented graphical reference for recording wattmeter, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
var
ANSI/IEEE reactive-power meter symbol
IEEE-oriented graphical reference for reactive-power meter, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
SYNC SCOPE
ANSI/IEEE synchronoscope symbol
IEEE-oriented graphical reference for synchronoscope, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
HOURS
ANSI/IEEE running-hours meter symbol
IEEE-oriented graphical reference for running-hours meter, with public vendor evidence and drawing-reading notes.
IEEE / ANSI
Q020804
Magnetic-field-effect qualifier
This qualifier identifies response to a magnetic field in the represented function.
IEC
Q020903
Ionising-radiation qualifier
An ionising-radiation qualifier identifies the radiation role attached to a measuring or operating function.
IEC
Q021701
Presumed-fault-location indication
This indication marks the presumed location of a fault or failure in a diagnostic diagram.
IEC
Q021702
Insulation-failure indication
An insulation-failure indication identifies the documented insulation-related failure condition.
IEC
HTC1LTB
Thermocouple with terminal board
This representation distinguishes a thermocouple circuit expanded to show its terminal-board interface.
IEC
HIN1P25
Pyrometer indication
A pyrometer indication identifies the documented temperature-measurement display function.
IEC
HIN1B10
Pressure-to-current converter
This representation identifies conversion of a pressure input to a current-signal output.
IEC
HIN1G1
Single-phase AC-to-DC current converter
This representation identifies the publisher's single-phase AC/DC current-conversion function.
IEC
HIN1B11
Tachometric dynamo
A tachometric dynamo indication identifies a speed-related generating measurement function.
IEC
HIN1B12
Impulse tachometric transducer
This representation distinguishes an impulse-output speed-measurement function.
IEC
HIN1B13
Optical tachometric transducer
This representation identifies optical speed-sensing in the publisher's tachometric family.
IEC
HPX1U
Ultrasonic proximity switch
An ultrasonic-switch representation identifies presence or distance switching using an ultrasonic sensing principle.
IEC
HPX11U
Ultrasonic NO switching output
This form identifies a normally-open switching output in the ultrasonic sensor family.
IEC
HPX12U
Ultrasonic NC switching output
This form identifies a normally-closed switching output in the ultrasonic sensor family.
IEC
HPX11U3
Three-wire ultrasonic sensor
This representation distinguishes a three-wire ultrasonic sensor interface from a simple contact depiction.
IEC
HSW1S90
Phase-to-phase voltmeter selector
This representation identifies selection among phase-to-phase voltage measurement connections.
IEC
HSW1S91
Phase-to-neutral voltmeter selector
This representation identifies selection among phase-to-neutral voltage measurement connections.
IEC
HSW1S92
Combined line and phase voltmeter selector
This representation identifies a selector covering phase-to-phase and phase-to-neutral voltage measurements.
IEC
HSW1S93
Two-network voltage measurement selector
This representation distinguishes voltage selection between two three-phase networks.
IEC
HSW1S94
Three-point current measurement selector
This representation identifies selection among three current-measurement points.
IEC
HSW1S95
Four-point current measurement selector
This representation identifies selection among four current-measurement points.
IEC