Có 2 phương pháp để hiển thị các chức năng của relay bảo vệ được sử dụng phổ biến. Một được cho trong tiêu chuẩn ANSI C37-2, và sử dụng hệ thống số cho những chức năng khác nhau. Các chức năng được bổ sung bằng các chữ cái nơi cần mở rộng chức năng. Phương pháp còn lại được cho trong IEC 60617, sử dụng các ký hiệu đồ họa. Để hỗ trợ kỹ sư bảo vệ hệ thống điện trong chuyển đổi từ hệ thống này đến hệ thống kia, một danh sách lựa chọn số thiết bị theo ANSI và IEC tương đương được cho ở bảng bên dưới.
Trước tiên ta xem xét mã số của các chức năng bảo vệ trong một sơ đồ bảo vệ một ngăn lộ điển hình như sau:
Sau khi xem kỹ sơ đồ ta xem các chức năng tương ứng theo ANSI và IEC ở bảng dưới đây:
Số hiệu, tên gọi relay bảo vệ theo ANSI update 2021
| 1 | Phần tử khống chế khởi động | Master element | A device, such as a control switch, etc., that serves, either directly or through such permissive devices as protective and time-delay relays, to place equipment in or out of operation. |
| 2 | Relay thời gian trễ tác động hoặc đóng | Time-delay starting or closing relay | A device that functions to give a desired amount of time delay before or after any point of operation in a switching sequence or protective relay system, except as specifically provided by device functions 48, 62, 79, and 82 |
| 3 | Relay kiểm tra và thực hiện liên động | Checking or interlocking relay | A device that operates in response to the position of one or more other devices or predetermined conditions in a piece of equipment or circuit, to allow an operating sequence to proceed, or to stop, or to provide a check of the position of these devices or conditions for any purpose |
| 4 | Công tắc tơ chính | Master contactor | A device, generally controlled by device function l or the equivalent and the required permissive and protective devices, that serves to make and break the necessary control circuits to place equipment into operation under the desired conditions and to take it out of operation under abnormal conditions |
| 5 | Thiết bị dừng điện | Stopping device | A control device used primarily to shut down equipment and hold it out of operation. [This device may be manually or electrically actuated, but it excludes the function of electrical lockout (see device function 86) on abnormal conditions] |
| 6 | Máy cắt khởi động | Starting circuit breaker | A device whose principal function is to connect a machine to its source of starting voltage |
| 7 | Relay tốc độ biến thiên | Rate-of-change relay | A device that operates when the rate-of-change of the measured quantity exceeds a threshold value, except as defined by device 63 |
| 8 | Thiết bị ngắt kết nối nguồn điều khiển | Control power disconnecting device | A device, such as a knife switch, circuit breaker, or pull-out fuse block, used for the purpose of connecting and disconnecting the source of control power to and from the control bus or equipment |
| 9 | Thiết bị đảo chiều | Reversing device | A device that is used for the purpose of reversing the field of a machine or for performing any other reversing function |
| 10 | Công tắc thay đổi trình tự khối | Unit sequence switch | A device that is used to change the sequence in which units may be placed in and out of service in multiple-unit equipment |
| 11 | Thiết bị đa chức năng | Multifunction device | A device that performs three or more comparatively important functions that could only be designated by combining several device function numbers. All of the functions performed by device 11 shall be defined in the drawing legend, device function definition list, or relay-setting record. See Annex A for further discussion and examples |
| 12 | Thiết bị quá tốc độ | Overspeed device | A device, usually direct-connected, that operates on machine overspeed |
| 13 | Thiết bị tốc độ đồng bộ | Synchronous-speed device | A device such as a centrifugal-speed switch, a slip-frequency relay, a voltage relay, an undercurrent relay, or any other type of device that operates at approximately the synchronous speed of a machine |
| 14 | Thiết bị tốc độ thấp | Underspeed device | A device that functions when the speed of a machine falls below a predetermined value |
| 15 | Thiết bị phù hợp tốc độ hoặc tần số | Speed or frequency matching device | A device that functions to match and hold the speed or frequency of a machine or a system equal to, or approximately equal to, that of another machine, source, or system. |
| 16 | Thiết bị truyền thông dữ liệu | Data communications device | A device that supports the serial and / or network communications that are a part of the substation control and protection system. This clause establishes the assignment of IEEE C37.2™ device number 16 for a data communications device handling protective relaying or other substation communication traffic. The following suffix list identifies specific functions of a component identified as device 16. The first suffix letter shall be either S (serial devices for RS-232, 422, or 485 communications) or E (for Ethernet components). The second and subsequent suffix letters shall be one or more of the following letters to further define the device: |
| C | Security processing function [Virtual Private Network (VPN), encryption, etc.] | ||
| F | Firewall or message filter function | ||
| M | Network managed function [e.g., configured via Simple Network Management Protocol (SNMP)] | ||
| R | Router | ||
| S | Switch (Examples: Port switch on a dial up connection is 16SS, and an Ethernet switch is 16ES) | ||
| T | Telephone component (Example: auto-answer modem) | ||
| 16EC or 16SC | Security processing function | VPN, encryption module, etc. | |
| 16EF | Firewall | Or message filtering function | |
| 16EM | Network managed function | (e.g., configured via SNMP) | |
| 16ER | Router | ||
| 16ES or 16SS | Switch | Example: Ethernet switch is 16ES, dial-up port switch is 16SS | |
| 16ESM | Ethernet managed switch | ||
| 16ERFCM | Ethernet router with firewall, VPN for secure communications | ||
| 17 | Công tắc xả hoặc phân dòng | Shunting or discharge switch | A device that serves to open or close a shunting circuit around any piece of apparatus (except a resistor), such as a machine field, a machine armature, a capacitor, or a reactor |
| 18 | Thiết bị tăng tốc hoặc giảm tốc | Accelerating or decelerating device | A device that is used to close or cause the closing of circuits that are used to increase or decrease the speed of a machine |
| 19 | Công tắc tơ chuyển tiếp từ lúc khởi động đến lúc làm việc | Starting-to-running transition contactor | A device that operates to initiate or cause the automatic transfer of a machine from the starting to the running power connection |
| 20 | Van hoạt động bằng điện | Electrically operated valve | An electrically-operated or -controlled device used in a fluid, air, gas, or vacuum line |
| 21 | Relay bảo vệ khoảng cách | Distance relay | A device that functions when the circuit admittance, impedance, or reactance increases or decreases beyond a predetermined value |
| 22 | Bộ ngắt mạch cân bằng | Equalizer circuit breaker | A device that serves to control or make and break the equalizer or the current balancing connections for a machine field, or for regulating equipment, in a multi-unit installation |
| 23 | Thiết bị điều khiển nhiệt độ | Temperature control device | A device that functions to control the temperature of a machine or other apparatus, or of any medium, when its temperature falls below or rises above a predetermined value |
| 24 | Relay bảo vệ tỷ số điện áp chia tần số | Volts per Hertz relay | A device that operates when the ratio of voltage to frequency is above a preset value or is below a different preset value. The relay may have any combination of instantaneous or time-delayed characteristics |
| 25 | Relay hòa đồng bộ | Synchronizing or synchronism-check relay | A synchronizing device that produces an output that causes closure of a circuit breaker between two circuits whose voltages are within prescribed limits of magnitude, phase angle, and frequency. It may or may not include voltage or speed control. A synchronism-check relay permits the paralleling of two circuits that are within prescribed (usually wider) limits of voltage magnitude, phase angle, and frequency |
| 26 | Thiết bị bảo vệ nhiệt độ | Apparatus thermal device | A device that functions when the temperature of the protected apparatus (other than the load-carrying windings of machines and transformers as covered by device function number 49), or that of a liquid or other medium, exceeds a predetermined value; or when the temperature of the protected apparatus or that of a liquid or other medium, exceeds a predetermined value or decreases below a predetermined value |
| 27 | Relay bảo vệ thấp áp | Undervoltage relay | A device that operates when its input voltage is less than a predetermined value |
| 28 | Thiết bị dò lửa | Flame detector | A device that monitors the presence of the pilot or main flame in such apparatus as a gas turbine or a steam boiler |
| 29 | Công tắc tơ hoặc công tắc cô lập điện | Isolating contactor or switch | A device that is used expressly for disconnecting one circuit from another for the purposes of emergency operation, maintenance, or testing |
| 30 | Relay chỉ báo | Annunciator relay | A nonautomatically reset device that gives a number of separate visual indications upon the functioning of protective devices and that may also be arranged to perform a lockout function |
| 31 | Thiết bị kích từ riêng biệt | Separate excitation device | A device that connects a circuit, such as the shunt field of a synchronous converter, to a source of separate excitation during the starting sequence |
| 32 | Relay bảo vệ hướng công suất | Directional power relay | A device that operates on a predetermined value of power flow in a given direction, such as reverse power flow resulting from the motoring of a generator upon loss of its prime mover |
| 33 | Công tắc vị trí | Position switch | A device that makes or breaks contact when the main device or piece of apparatus that has no device function number reaches a given position |
| 34 | Thiết bị thứ tự chính | Master sequence device | A device such as a motor-operated multi-contact switch (or the equivalent), or a programmable device, that establishes or determines the operating sequence of the major devices in equipment during starting and stopping, or during sequential switching operations |
| 35 | Thiết bị ngắn mạch bằng chổi than hoặc vòng trượt | Brush-operating or slip-ring short-circuiting device | A device for raising, lowering, or shifting the brushes of a machine; short-circuiting its slip rings; or engaging or disengaging the contacts of a mechanical rectifier |
| 36 | Thiết bị phân cực điện áp | Polarity or polarizing voltage device | A device that operates, or permits the operation of, another device on a predetermined polarity only, or that verifies the presence of a polarizing voltage in equipment |
| 37 | Relay bảo vế thấp dòng hoặc thấp công suất | Undercurrent or underpower relay | A device that functions when the current or power flow decreases below a predetermined value |
| 38 | Thiết bị bảo vệ ổ trục | Bearing protective device | A device that activates upon excessive bearing temperature or on other abnormal mechanical conditions associated with bearings, such as undue wear, which may eventually result in excessive bearing temperature or failure |
| 39 | Giám sát điều kiện cơ học | Mechanical condition monitor | A device that activates upon the occurrence of an abnormal mechanical condition (except conditions associated with bearings as covered under device function 38), such as excessive vibration, eccentricity, expansion, shock, tilting, or seal failure |
| 40 | Relay trường (quá/dưới kích thích) | Field (over / under excitation) relay | A device that activates upon a given or abnormally high or low value or failure of machine field current, or on an excessive value of the reactive component of armature current in an ac machine indicating abnormally high or low field excitation |
| 41 | Máy cắt trường | Field circuit breaker | A device that functions to apply or remove the field excitation of a machine |
| 42 | Máy cắt vận hành | Running circuit breaker | A device whose function is to connect a machine to its source of running or operating voltage. This function may also be used for a device, such as a contactor, that is used in series with a circuit breaker or other fault-protecting means, primarily for frequent opening and closing of the circuit |
| 43 | Thiết bị lựa chon hoặc chuyển đổi bằng tay | Manual transfer or selector device | A manually operated device that transfers control or potential circuits in order to modify the plan of operation of the associated equipment or of some of the associated devices |
| 44 | Relay khởi động theo trình tự khối | Unit sequence starting relay | A device that functions to start the next available unit in multiple-unit equipment upon the failure or non-availability of the normally preceding unit |
| 45 | Giám sát điều kiện áp suất không bình thường | Abnormal atmospheric condition monitor | A device that functions upon the occurrence of an abnormal atmospheric condition, such as damaging fumes, explosive mixtures, smoke, or fire |
| 46 | Relay bảo vệ ngược pha hoặc mất cân bằng dòng điện | Reverse-phase or phase-balance current relay | A device in a polyphase circuit that operates when the polyphase currents are of reverse-phase sequence, or when the polyphase currents are unbalanced, or when the negative phase-sequence current exceeds a preset value |
| 47 | Relay bảo vệ thứ tự pha hoặc mất cân bằng điện áp | Phase-sequence or phase-balance voltage relay | A device in a polyphase circuit that functions upon a predetermined value of polyphase voltage in the desired phase sequence when the polyphase voltages are unbalanced, or when the negative phase-sequence voltage exceeds a preset value |
| 48 | Relay bảo vệ chưa hết hành trình | Incomplete sequence relay | A device that returns the equipment to the normal or off position and locks it out if the normal starting, operating, or stopping sequence is not properly completed within a predetermined time |
| 49 | Relay bảo vệ nhiệt độ máy biến áp | Machine or transformer thermal relay | A device that functions when the temperature of a machine armature winding or other load-carrying winding or element of a machine or power transformer exceeds a predetermined value |
| 50 | Relay bảo vệ quá dòng cắt nhanh | Instantaneous overcurrent relay | A device that operates with no intentional time delay when the current exceeds a preset value. The suffix TD should be used (e.g., 50TD) to describe a definite time overcurrent function. Use 50BF for a current-monitored breaker failure function |
| 51 | Relay bảo vệ quá dòng có thời gian | ac inverse time overcurrent relay | A device that functions when the ac input current exceeds a predetermined value, and in which the input current and operating time are inversely related through a substantial portion of the performance range |
| 52 | Máy cắt điện | ac circuit breaker | A device that is used to close and interrupt an ac power circuit under normal conditions or to interrupt this circuit under fault or emergency conditions |
| 53 | Relay bảo vệ kích từ | Field excitation relay | A device that forces the dc machine field excitation to build up during starting or that functions when the machine voltage has built up to a given value |
| 54 | Thiết bị kéo bánh răng quay | Turning gear engaging device | A device either electrically operated, controlled, or monitored that functions to cause the turning gear to engage (or disengage) the machine shaft |
| 55 | Relay hệ số công suất | Power factor relay | A device that operates when the power factor in an ac circuit rises above or falls below a predetermined value |
| 56 | Relay ứng dụng trường | Field application relay | A device that automatically controls the application of the field excitation to a synchronous ac motor at some predetermined point in the slip cycle |
| 57 | Thiết bị ngắn mạch hoặc nối đất | Short-circuiting or grounding device | A device that functions to short-circuit or ground a circuit in response to automatic or manual means |
| 58 | Relay sự cố chỉnh lưu | Rectification failure relay | A device that functions if a power rectifier (diode) fails to conduct or block properly |
| 59 | Relay bảo vệ quá áp | Overvoltage relay | A device that operates when its input voltage exceeds a predetermined value |
| 60 | Relay cân bằng điện áp hoặc dòng điện | Voltage or current balance relay | A device that operates on a given difference in voltage, or current input or output, of two circuits |
| 61 | Công tắc mật độ hoặc cảm biến | Density switch or sensor | A device that operates at a given density value or at a given rate of change of density |
| 62 | Relay thời gian trễ dừng hoặc mở | Time-delay stopping or opening relay | A device that imposes a time delay in conjunction with the device that initiates the shutdown, stopping, or opening operation in an automatic sequence. Example: 62BF = breaker failure function (with no current monitoring) |
| 63 | Công tắc áp suất | Pressure switch | A device that operates at a given pressure value or at a given rate of change of pressure |
| 64 | Relay bảo vệ chạm đất | Ground detector relay | A device that operates upon the insulation failure of a machine or other apparatus to ground. NOTE—This function is not applied to a device connected in the secondary circuit of current transformers in a normally grounded power system where other overcurrent device numbers with the suffix G or N should be used; for example, 51N for an ac time overcurrent relay connected in the secondary neutral of the current transformers |
| 65 | Bộ điều tốc | Governor | A device consisting of an assembly of fluid, electrical, or mechanical control equipment used for regulating the flow of water, steam, or other media to the prime mover for such purposes as starting, holding speed or load, or stopping |
| 66 | Thiết bị cắt rãnh hoặc lắc nhẹ | Notching or jogging device | A device that functions to allow only a specified number of operations of a given device or piece of equipment, or a specified number of successive operations within a given time of each other. It is also a device that functions to energize a circuit periodically or for fractions of specified time intervals, or that is used to permit intermittent acceleration or jogging of a machine at low speeds for mechanical positioning. |
| 67 | Relay bảo vệ quá dòng có hướng | ac directional overcurrent relay | A device that functions at a desired value of ac overcurrent flowing in a predetermined direction |
| 68 | Relay khóa | blocking or “out-of-step” relay | A device that initiates a pilot signal for blocking of tripping on external faults in a transmission line or in other apparatus under predetermined conditions, or cooperates with other devices to block tripping or reclosing on an out-of-step condition or on power swings |
| 69 | Thiết bị cho phép điều khiển | Permissive control device | A device with two positions that, in one position permits the closing of a circuit breaker, or the placing of a piece of equipment into operation, and in the other position, prevents the circuit breaker or the equipment from being operated |
| 70 | Biến trở | Rheostat | A device used to vary the resistance in an electric circuit when the device is electrically operated or has other electrical accessories, such as auxiliary, position, or limit switches |
| 71 | Công tắc mức chất lỏng | Liquid level switch | A device that operates at a given level value, or on a given rate of change of level of a liquid |
| 72 | Máy cắt điện một chiều | DC circuit breaker | A device that is used to close and interrupt a dc power circuit under normal conditions or to interrupt this circuit under fault or emergency conditions |
| 73 | Công tắc tơ tải điện trở | Load-resistor contactor | A device that is used to shunt or insert a step of load limiting, shifting, or indicating resistance in a power circuit; to switch a space heater in circuit; or to switch a light or regenerative load resistor of a power rectifier or other machine in and out of circuit |
| 74 | Relay cảnh báo | Alarm relay | A device other than an annunciator, as covered under device function 30, that is used to operate, or that operates in connection with, a visual or audible alarm |
| 75 | Cơ cấu thay đổi vị trí | Position changing mechanism | A device that is used for moving a main device from one position to another in equipment; for example, shifting a removable circuit breaker unit to and from the connected, disconnected, and test positions |
| 76 | Relay quá dòng một chiều | DC overcurrent relay | A device that functions when the current in a dc circuit exceeds a given value |
| 77 | Thiết bị đo từ xa | Telemetering device | A transmitting device used to generate and transmit to a remote location an electrical signal representing a measured quantity; or a receiver used to receive the electrical signal from a remote transmitter and convert the signal to represent the original measured quantity |
| 78 | Relay đo góc pha | Phase-angle measuring relay | A device that functions at a predetermined phase angle between two voltages, between two currents, or between a voltage and a current |
| 79 | Relay đóng lặp lại | AC reclosing relay | A device that controls the automatic reclosing and locking out of an ac circuit breaker |
| 80 | Công tắc dòng chảy | Flow switch | A device that operates at a given flow value, or at a given rate of change of flow |
| 81 | Relay tần số | Frequency relay | A device that responds to the frequency of an electrical quantity, operating when the frequency or rate of change of frequency exceeds or is less than a predetermined value |
| 82 | Relay đóng lặp lại và đo lường tải một chiều | DC load-measuring reclosing relay | A device that controls the automatic closing and reclosing of a dc circuit interrupter, generally in response to load circuit conditions |
| 83 | Relay tự động điều khiển lựa chọn hoặc chuyển tiếp | Automatic selective control or transfer relay | A device that operates to select automatically between certain sources or conditions in equipment or that performs a transfer operation automatically |
| 84 | Cơ cấu hoạt động | Operating mechanism | A device consisting of the complete electrical mechanism or servomechanism, including the operating motor, solenoids, position switches, etc., for a tap changer, induction regulator, or any similar piece of apparatus that otherwise has no device function number |
| 85 | Relay truyền nhận thông tin liên lạc qua dây hoa tiêu dẫn | Pilot communications, carrier or pilot-wire relay | A device that is operated, restrained, or has its function modified by communications transmitted or received via any media used for relaying |
| 86 | Relay khóa đầu ra | Lockout relay | A device that trips and maintains the associated equipment or devices as inoperative until it is reset by an operator, either locally or remotely |
| 87 | Relay bảo vệ so lệch | Differential protective relay | A device that operates on a percentage, phase angle, or other quantitative difference of two or more currents or other electrical quantities |
| 88 | Động cơ phụ hoặc máy phát động cơ | Auxiliary motor or motor generator | A device used for operating auxiliary equipment, such as pumps, blowers, exciters, rotating magnetic amplifiers, etc |
| 89 | Công tắc nguồn | Line switch | A device used as a disconnecting, load-interrupter, circuit switcher, or isolating switch in an ac or dc power circuit. (This device function number is normally not necessary unless the switch is electrically operated or has electrical accessories, such as an auxiliary switch, a magnetic lock, etc.) |
| 90 | Thiết bị điều chỉnh | Regulating device | A device that functions to regulate a quantity or quantities, such as voltage, current, power, speed, frequency, temperature, and load, at a certain value or between certain (generally close) limits for machines, tie lines, or other apparatus |
| 91 | Relay hướng điện áp | Voltage directional relay | A device that operates when the voltage across an open circuit breaker or contactor exceeds a given value in a given direction |
| 92 | Relay hướng điện áp và công suất | Voltage and power directional relay | A device that permits or causes the connection of two circuits when the voltage difference between them exceeds a given value in a predetermined direction and causes these two circuits to be disconnected from each other when the power flowing between them exceeds a given value in the opposite direction |
| 93 | Công tắc tơ thay đổi trường | Field-changing contactor | A device that functions to increase or decrease, in one step, the value of field excitation on a machine |
| 94 | Relay cắt đầu ra | Tripping or trip-free relay | A self-resetting device that functions to trip a circuit breaker, contactor, or piece of equipment; to permit immediate tripping by other devices; or to prevent immediate reclosing of a circuit interrupter if it should open automatically, even though its closing circuit is activated or energized |
| 95-99 | Chỉ được sử dụng cho các ứng dụng cụ thể | Used only for specific applications | These device numbers are used in individual specific installations if none of the functions assigned to the numbers from 1 through 94 in 3.1 or the acronyms in 3.2 are suitable |
Các từ viết tắt của thiết bị / chức năng theo ANSI
| AFD | Arc flash detector | A device / function that detects an unintentional electrical arc in air |
| CLK | Clock or timing source | A device / function that receives an accurate timing signal input and distributes an accurate timing signal output to other devices |
| DDR | Dynamic disturbance recorder | A device / function that records incidents that portray power system behavior during low frequency (0.1 Hz to 3 Hz) oscillations, and abnormal frequency or voltage excursions |
| DFR | Digital fault recorder | A device / function that records, for analysis purposes, events on the power system. It records voltage and / or current waveforms replicating the primary power system voltages and currents when triggered by a sudden change in the waveforms or by an external event |
| ENV | Environmental data | A device / function that measures and stores variables relating to the environment, such as weather data, ice buildup conditions, geomagnetic disturbances, earthquakes, and other similar phenomena |
| HIZ | High impedance fault detector | A device / function that detects high impedance faults on grounded or ungrounded systems |
| HMI | Human machine interface | A device / function that displays data / information to and allows control of a system by an operator. A HMI may also be local to a specific device for operator interaction specific to that device |
| HST | Historian | A device / function that continuously gathers states and values from a data concentrator or directly from protection and control Intelligent Electronic Devices (IEDs), and may also act as a recorder of data from which trends may be determined |
| LGC | Scheme logic | A device / function that provides the programmed logic for a multi-device control / protective relay scheme, such as a Remedial Action Scheme (RAS) or an interlocking scheme |
| MET | Substation metering | A device /function that is connected to CTs and VTs, and may calculate and store one or several of the following quantities—watts, vars, amps, volts, power factor, demand, energy |
| PDC | Phasor data concentrator | A device /function that collects phasor and discrete event data from PMUs (and from other PDCs) and transmits the data to other destinations. PDCs may buffer data for a short time period, but do not store the data |
| PMU | Phasor measurement unit | A device /function that samples voltage and current with very accurate time stamps and calculates phase angles vs. a GPS time reference (synchrophasors). See IEEE Std 1344™ [B5]2 |
| PQM | Power quality monitor | A device / function that monitors electrical parameters used in power quality measurements. Parameters include (but are not limited to) RMS variations, frequency variations, unbalance, transients, harmonics, and inter-harmonics. The storage of historical values of these measurements may also be performed. See IEEE Std 1159™ [B4] |
| RIO | Remote input / output device | A device /function interfacing between the power system process (analog or digital) and the substation automation system that serves as a substation data repository of control and protection system information, but without connection to a SCADA master station |
| RTU | Remote terminal unit / data concentrator | A device / function that serves as the primary interface (the data concentrator function) between a protection and control system and a SCADA system to provide operational data visibility to, and perform command operations from, the SCADA control center. See IEEE Std C37.1™ [B7] |
| SER | Sequence of events recorder | A device / function that records events (changes of state of equipment or functions) with a time reference (commonly from a GPS or IRIG-B receiver) |
| TCM | Trip circuit monitor | A device /function that monitors an associated circuit breaker’s trip circuit for continuity and for the presence of tripping voltage, and sets an externally readable alarm when continuity or tripping voltage is lost (a surrogate for the traditional red light on relay and control panels) |