Thông thường, ta lựa chọn các relay bảo vệ theo chức năng bảo vệ, ví dụ : relay bảo vệ quá dòng, relay bảo vệ chạm đất, relay bảo vệ dòng rò, relay bảo vệ quá áp, relay bảo vệ thiếu áp, relay bảo vệ mất pha, relay bảo vệ đảo pha, relay bảo vệ thiếu tần số, relay bảo vệ quá tần số, relay bảo vệ lock rotor động cơ...
Tuy nhiên trong một số bản vẽ kỹ thuật, chức năng các relay bảo vệ thường được ký hiệu bằng số ví dụ 50, 50N, 51, 51N. Để chọn được đúng các relay theo các bản vẽ này ta phải hiểu được ý nghĩa các thông số ký hiệu relay này.
Thông thường các relay được ký hiệu số như trên sẽ tuân thủ theo ký hiệu của bảng tên gọi relay theo ANSI như sau :
- 1: Phần tử chỉ huy khởi động
- 2: Rơle trung gian (chỉ huy đóng hoặc khởi động) có trễ thời gian
- 3: Rơle liên động hoặc kiểm tra
- 4: Côngtắctơ chính
- 5: Thiết bị làm ngưng hoạt động
- 6: Máy cắt khởi động
- 7: Rơle tăng tỷ lệ
- 8: Thiết bị cách ly nguồn điều khiển
- 9: Thiết bị phục hồi
- 10: Đóng cắt phối hợp thiết bị
- 11: Thiết bị đa chức năng
- 12: Thiết bị chống vượt tốc
- 13: Thiết bị tác động theo tốc độ đồng bộ
- 14: Chức năng giảm tốc độ
- 15: Thiết bị bám tốc độ hoặc tần số phù hợp với thiết bị song hành
- 16: Dự phòng cho tương lai hiện chưa sử dụng
- 17: Khóa đóng cắt mạch shunt hoặc phóng điện
- 18: Thiết bị gia tốc hoặc giảm tốc độ đóng
- 19: Côngtắctơ khởi động thiết bị có quá độ (thiết bị khởi động qua nhiều mức tăng dần)
- 20: Van vận hành bằng điện
- 21. Rơle khoảng cách
- 22: Mắy cắt tác động điều khiển cân bằng
- 23: Thiết bị điều khiển nhiệt độ
- 24: Rơle tỷ số V/Hz (điện áp/tần số), chức năng quá kích thích
- 25: Chức năng kiểm tra đồng bộ
- 26: Chức năng bảo vệ
- 27: Chức năng bảo vệ kém áp
- 28: Bộ giám sát ngọn lửa (với tuabin khí hoặc nồi hơi)
- 29: Côngtắctơ tạo cách ly
- 30: Rơle tín hiệu (không tự giải trừ được)
- 31: Bộ kích mở cách ly (kích mở thyristor)
- 32: Chức năng định hướng công suất
- 33: Khoá vị trí
- 34: Thiết bị đặt lịch trình làm việc
- 35: Cổ góp chổi than hoặc vành xuyến trượt có chổi than
- 36: Rơle phân cực
- 37: Chức năng bảo vệ kém áp hoặc kém công suất
- 38: Chức năng đo nhiệt độ vòng bi hoặc gối trục
- 39: Chức năng đo độ rung
- 40: Chức năng bảo vệ chống mất kích từ
- 41: Máy cắt dập từ
- 42: Máy cắt khởi động máy hoặc thiết bị
- 43: Thiết bị chuyển đổi hoặc chọn mạch điều khiển bằng tay
- 44: Rơle khởi động khối chức năng kế tiếp vào thay thế
- 45: Rơle giám sát tình trạng không khí (khói, lửa, chất nổ v.v.)
- 46: Rơle dòng điện thứ tự nghịch hoặc bộ lọc dòng điện thứ tự thuận
- 47: Rơle điện áp thứ tự nghịch hoặc bộ lọc điện áp thứ tự thuận
- 48: Rơle bảo vệ duy trì trình tự
- 49: Rơle nhiệt (bảo vệ quá nhiệt)
- 50: Bảo vệ quá dòng cắt nhanh
- 50N: Bảo vệ quá dòng cắt nhanh chạm đất
- 51: Bảo vệ quá dòng (xoay chiều) có thời gian
- 51N: Bảo vệ quá dòng chạm đất có thời gian duy trì
- 52: Máy cắt dòng điện xoay chiều
- 53: Rơle cưỡng bức kích thích điện trường cho máy điện một chiều
- 54: Thiết bị chuyển số cơ khí được điều khiển bằng điện
- 55: Rơle hệ số công suất
- 56: Rơle điều khiển áp dụng điện trường kích thích cho động cơ xoay chiều
- 57: Thiết bị nối đất hoặc làm ngắn mạch
- 58: Rơle ngăn chặn hư hỏng chỉnh lưu
- 59: Rơle quá điện áp
- 60: Rơle cân bằng điện áp hoặc dòng điện
- 61: Cảm biến hoặc khóa đóng cắt theo mật độ khí
- 62: Rơle duy trì thời gian đóng hoặc mở tiếp điểm
- 63: Rơle áp lực (Buchholz)
- 64: Rơle phát hiện chạm đất
- 64R: Bảo vệ chống chạm đất cho cuộn rôto
- 64G: Bảo vệ chống chạm đất cho cuộn stato
- 65: Bộ điều tốc
- 66: Chức năng đếm số lần khởi động trong một giờ
- 67: Rơle bảo vệ quá dòng có hướng
- 67N: Rơle bảo vệ quá dòng chạm đất có hướng
- 68: Rơle khoá
- 69: Thiết bị cho phép điều khiển
- 70: Biến trở
- 71: Rơle mức dầu
- 72: Máy cắt điện một chiều
- 73: Tiếp điểm có trở chịu dòng tải
- 74: Rơle cảnh báo (rơle tín hiệu)
- 75: Cơ cấu thay đổi vị trí
- 76: Rơle bảo vệ quá dòng một chiều
- 77: Thiết bị đo xa
- 78: Rơle bảo vệ góc lệch pha
- 79: Rơle tự đóng lại (điện xoay chiều)
- 80: Thiết bị chuyển đổi theo trào lưu chạy qua
- 81: Rơle tần số
- 82: Rơle đóng lặp lại theo mức mang tải mạch điện một chiều
- 83: Rơle chuyển đổi hoặc chọn điều khiển tự động
- 84: Bộ điều áp máy biến áp (OLTC)
- 85: Rơle nhận thông tin phối hợp tác động từ bảo vệ đầu đối diện
- 86: Rơle khoá đầu ra
- 87: Bảo vệ so lệch
- 87B: Rơle bảo vệ so lệch thanh cái
- 87G: Rơle bảo vệ so lệch máy phát
- 87L: Rơle bảo vệ so lệch đường dây
- 87M: Rơle bảo vệ so lệch động cơ
- 87T: Rơle bảo vệ so lệch máy biến áp
- 87TG: Rơle bảo vệ so lệch hạn chế máy biến áp chạm đất (chỉ giới hạn cho cuộn dây đấu sao có nối đất)
- 88: Động cơ phụ hoặc máy phát động cơ
- 89: Khóa đóng cắt mạch
- 90: Rơle điều chỉnh (điện áp, dòng điện, công suất, tốc độ, tần số, nhiệt độ)
- 91: Rơle điện áp có hướng
- 92: Rơle điện áp và công suất có hướng
- 93: Các chức năng tiếp điểm thay đổi kích thích
- 94: Rơle cắt đầu ra
- 95: Chức năng đồng bộ (cho động cơ đồng bộ có tải nhỏ và quán tính nhỏ) bằng hiệu ứng mômen từ trở
- 96: Chức năng tự động đổi tải cơ học
Trong một số trường hợp, bản vẽ sử dụng các ký hiệu theo tiêu chuẩn IEC. Ta có thể sử dụng bảng sau để tra cứu chức năng của relay :
Bảng so sánh mã số relay bảo vệ theo ANSI và ký hiệu rơle bảo vệ theo IEC
nguồn: dien-congnghiep.com
| No. | Device | Description |
| 1 | .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.
NOTE: This number is normally used for a hand-operated device, although it may also be used for an electrical or mechanical device for which no other function number is suitable.
|
| 2 | .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 | .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 | .Master contactor | A device, generally controlled by device function 1 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 | .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 | .Starting circuit breaker | A device whose principal function is to connect a machine to its source of starting voltage. |
| 7 | .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 (see 3.1.63). |
| 8 | .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.
NOTE: Control power is considered to include auxiliary power that supplies such apparatus as small motors and heaters.
|
| 9 | .Reversing device | A device that is used for the purpose of reversing a machine field or for performing any other reversing function. |
| 10 | .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 | .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. |
| 12 | .Overspeed device | A device, usually direct connected, that operates on machine overspeed. |
| 13 | .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 | .Underspeed device | A device that functions when the speed of a machine falls below a predetermined value. |
| 15 | .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 | .Not used | Reserved for future application. |
| 17 | .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.NOTE: This excludes devices that perform such shunting operations as may be necessary in the process of starting a machine by devices 6 or 42 (or their equivalent) and also excludes device function 73 that serves for the switching of resistors. |
| 18 | .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 | .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 | .Electrically operated.valve | An electrically operated, controlled, or monitored device used in a fluid, air, gas, or vacuum line.
NOTE: The function of the valve may be more completely indicated by the use of suffixes.
|
| 21 | .Distance relay | A device that functions when the circuit admittance, impedance, or reactance increases or decreases beyond a predetermined value. |
| 22 | .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 multiple-unit installation. |
| 23 | .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.
NOTE: An example is a thermostat that switches on a space heater in a switchgear assembly when the temperature falls to a desired value. This should be distinguished from a device that is used to provide automatic temperature regulation between close limits and would be designated as device function 90T.
|
| 24 | .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 | .Synchronizing or.synchronism-check.relay | A synchronizing device produces an output that causes closure at zero-phase angle difference between two circuits. It may or may not include voltage and speed control. A synchronism-check relay permits the paralleling of two circuits that are within prescribed limits of voltage magnitude, phase angle, and frequency. |
| 26 | .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 of a liquid or other medium exceeds a predetermined value; or when the temperature of the protected apparatus or of any medium decreases below a predetermined value. |
| 27 | .Undervoltage relay | A device that operates when its input voltage is less than a predetermined value. |
| 28 | .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 | .Isolating contactor or.switch | A device that is used expressly for disconnecting one circuit from another for the purposes of emergency operation, maintenance, or test. |
| 30 | .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 | .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 | .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 | .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 | .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 stop-ping or during sequential switching operations. |
| 35 | .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 | .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 | .Undercurrent or.underpower relay | A device that functions when the current or power flow decreases below a predetermined value. |
| 38 | .Bearing protective.device | A device that functions on excessive bearing temperature or on other abnormal mechanical conditions associated with the bearing, such as undue wear, which may eventually result in excessive bearing temperature or failure. |
| 39 | .Mechanical condition.monitor | A device that functions upon the occurrence of an abnormal mechanical condition (except that associated with bearings as covered under device function 38), such as excessive vibration, eccentricity, expansion, shock, tilting, or seal failure. |
| 40 | .Field relay | A device that functions on 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 | .Field circuit breaker | A device that functions to apply or remove the field excitation of a machine. |
| 42 | .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 | .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 | .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 | .Atmosphericcondition .monitor | A device that functions upon the occurrence of an abnormal atmospheric condition, such as damaging fumes, explosive mixtures, smoke, or fire. |
| 46 | .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 | .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 | .Incomplete sequence.relay | A device that generally 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 | .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 | .Instantaneous.overcurrent relay | A device that operates with no intentional time delay when the current exceeds a preset value. |
| 51 | .AC time overcurrent.relay | A device that functions when the ac input current exceeds a predetermined value, and in which the input cur-rent and operating time are inversely related through a substantial portion of the performance range. |
| 52 | .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 | .Exciter or dc generator .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 | .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 | .Power factor relay | A device that operates when the power factor in an ac circuit rises above or falls below a predetermined value. |
| 56 | .Field application relay | A device that automatically controls the application of the field excitation to an ac motor at some predetermined point in the slip cycle. |
| 57 | .Short-circuiting or.grounding device | A device that functions to short-circuit or ground a circuit in response to automatic or manual means. |
| 58 | .Rectification failure.relay | A device that functions if a power rectifier fails to conduct or block properly. |
| 59 | .Overvoltage relay | A device that operates when its input voltage exceeds a predetermined value. |
| 60 | .Voltage or current.balance relay | A device that operates on a given difference in voltage, or current input or output, of two circuits. |
| 61 | .Density switch or.sensor | A device that operates at a given density value or at a given rate of change of density. |
| 62 | .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 or protective relay system. |
| 63 | .Pressure switch | A device that operates at a given pressure value or at a given rate of change of pressure. |
| 64 | .Ground detector relay | A device that operates upon failure of machine or other apparatus insulation 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 | .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 | .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 | .AC directional.overcurrent relay | A device that functions at a desired value of ac overcurrent flowing in a predetermined direction. |
| 68 | .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 | .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 | .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 | .Level switch | A device that operates at a given level value, or on a given rate of change of level. |
| 72 | .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 | .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 | .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 | .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 | .DC overcurrent relay | A device that functions when the current in a dc circuit exceeds a given value. |
| 77 | .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 | .Phase-angle.measuring relay | A device that functions at a predetermined phase angle between two voltages, between two currents, or between voltage and current. |
| 79 | .Reclosing relay | A device that controls the automatic reclosing and locking out of an ac circuit interrupter. |
| 80 | .Flow switch | A device that operates at a given flow value, or at a given rate of change of flow. |
| 81 | .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 | .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 | .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 | .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 | .Carrier or pilot-wire.relay | A device that is operated or restrained by a signal transmitted or received via any communications media used for relaying. |
| 86 | .Lockout relay | A device that trips and maintains the associated equipment or devices inoperative until it is reset by an operator, either locally or remotely. |
| 87 | .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 | .Auxiliary motor or.motor generator | A device used for operating auxiliary equipment, such as pumps, blowers, exciters, rotating magnetic amplifiers, etc. |
| 89 | .Line switch | A device used as a disconnecting, load-interrupter, 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 | .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 | .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 | .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 | .Field-changing.contactor | A device that functions to increase or decrease, in one step, the value of field excitation on a machine. |
| 94 | .Tripping or trip-free.relay | A device that functions to trip a circuit breaker, contactor, or 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 maintained closed. |
| 95- 99 | .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 are suitable. |
