Refer to Figure 5 and the test switches for the outputs of relays 87TP and 50/51TBU. These detailed connections often include terminal numbers. Examples of this can be seen in Figures 1, 2 and 3. The relay is used in the places where there the magnitude of the short-circuit current fall rapidly because of the large distance from the source. A wiring diagram is a simplified traditional pictorial depiction of an electrical circuit. A relay is automatic device which senses an abnormal condition of electrical circuit and closes its contacts. Technical Explanation for Motor Protective Relay Introduction Functions Required of Motor Protective Relays Motor Protective Relay applications can be grouped by purpose into the following categories. Since the details in these standards often differ slightly but significantly from utility to utility, it is important to understand the standards when reviewing these types of drawings. It will continue downward as you will see later on. It is is our primary source when designing the protection schematics of this substation. This circuit powered using a 12V regulated power supply. The report will exclude ac voltage and current inputs, GOOSE, internals of relays, and IRIG and communication issues. Examples of protection relays Relays and relay parts Auxiliary relay with mechanical contacts ... connection diagrams, in instruction books, and in specifications. With the use of these relays to perform metering functions, it is no longer necessary to carefully detail all the transducers needed to perform the same functions. The IEDs, once programmed to communicate with each other, will manage the messages they have been programmed to receive and transmit. Some relays are constructed with a kind of “shock absorber” mechanism attached to the armature which prevents immediate, full motion when the coil is either energized or de-energized. Fig. Here is a schematic diagram for a simple circuit that uses a 9 VDC circuit with a handheld pushbutton to turn a 120 VAC lamp on and off. The first part is the primary winding of a current transformer (C.T.) Discreet metering devices including panel meters and transducers are often no longer required. Because of under voltage input. The content is copyrighted to EEP and may not be reproduced on other websites. There are also functional similarities with the AC schematics. 50 : Instantaneous-overcurrent relay . FIG. The changes of elementary wiring diagrams often require a process of obtaining approvals that hinders making changes often. This includes AC schematics and DC schematics and diagrams that prominently feature relaying.There are other equally important types of drawings that are not the subject of this article including logic diagrams, data tables and single line diagrams, wiring diagrams, data communication s… So, similar to the wiring diagram, if logic is using an “OR” function then the variables are shown in parallel. The AC schematic will show the point on the high voltage system where each VT is attached and provide both primary and secondary connection details for each of the phases. Therefore IEC 61850 GOOSE messages (signals) are best represented in a point-to-point list or spreadsheet format (e.g. %PDF-1.6 %���� If an “AND” function is used then the variables are shown in series. If the voltage falls below a preset. It helps you. The circuit diagram of a manual aut0transfotmercontrolled DC drive of a 230V, 5HP DC motor with a separately excited shunt field of 230 volts ( l.l3 amps) and the FFR (field failure relay) circuit are shown in circuits diagram respectively. Multi-ratio current transformers are commonly used for protective relay applications. Fig. Normal voltage is 220V AC. This paper is intended to supplement to the existing 1999 relay trip circuit design paper to address the use microprocessor relays. The circuit breaker after taking the command from the protective relay, disconnect the faulted element. input circuit. LED. In this schematic, the resistor R in parallel with the flyback diode wiring represents the coil's intrinsic DC resistance. which is connected in series with the line to be protected. As with traditional designs, utilities will continue to document the hardware connection on the elementary wiring diagram. The inverse characteristic of the relay is more than the IDMT. An electrical system signal quantity is monitored and applied to a filter and to a bipolar threshold device in parallel with the filter. I’m already a regular follower of EEP. relay trips, thereby closing R1. delta or wye) will be indicated on the drawing. Simple circuit with relay that directs output at the correct polarity when DC input is reversed. 460 0 obj <> endobj a notation we might sketch using pencil on a diagram to help us follow the operation of the circuit). 2: Close Circuit of Tie relay Trip and close circuits for both Mains and the Tie would also be illustrated and documented. 51 - AC Time Overcurrent Relay 52 - AC Circuit Breaker 53 - Exciter or DC Generator Relay 54 - High-Speed DC Circuit Breaker 55 - Power Factor Relay 56 - Field Application Relay 59 - Overvoltage Relay 60 - Voltage or Current Balance Relay 62 - Time-Delay Stopping or Opening Relay 63 - Pressure Switch 64 - Ground Detector Relay 65 - Governor Figure 6 provides examples of standards that have been developed regarding the details of the design. 474 0 obj <>stream Early applications of relay protocols provided engineers with basic tools for substation automation, but they were often limited in functionality. Reading and Understanding AC and DC Schematics In Protection And Control Relaying, Electrical engineer, programmer and founder of, Voltage Transformers (VT) or Potential Transformers (PT), DC Schematics and the Microprocessor Relay, Generic Substation Events (GSE) or Generic Object Oriented Substation Events (GOOSE). Because of this feature, it eliminates most dedicated control wiring that would normally be wired from relay-to-relay (i.e. 51 . The principle is simple, it will check for voltage at all times. Logic diagrams could also be used as the additional documentation to show how the design is developed. Details will typically include winding ratios, number of  primary and secondary taps, polarity marks, nominal voltage ratings, and winding configuration (e.g. relay model with the complete trip circuit up to the trip coil of the circuit breaker. Knowledge of true protective relay characteristics has not been communicated fully and properly from protective relay designers and protection engineers, to field test technicians. primarily as it applies to trip and control circuits. 4. Another vital function of the AC schematic is to show how the AC current and voltage circuits can be isolated for testing. Felicitaciones y gracias por compartir este valioso material técnico . For a 12V amplifier you need a 12V relay and so on. The ground fault protection scheme developed involves an overvoltage relay, connected across broken delta-connected VTs, that monitors zero sequence voltage. The circuit can be assembled on a Vero board. AC Main Over Voltage Protection Circuit . IEC 61850 differs from other standards/protocols because it comprises several standards describing client/server and peer-to-peer communications, substation design and configuration, and testing. I am a tacnical person and i like this tacnical work. Now these diagrams are known as relay logic or ladder diagrams. With the open architecture, it freely supports allocation of C37.2 device functions. This technical article explains the AC/DC schematic representation of the protection and control systems used on power networks. As a result, many misunderstandings about R-X diagrams and impedance relay characteristics are widely held. Block diagram of a wired doorbell camera with the recommended protection and control components . Very useful information. Thus, only 9 VDC passes through the handheld pushbutton. The relay in the circuit has a coil rated for 9 VDC and a switch rating of 10 A at 117 VAC. 1. The transistor allows the HC11 to control the medium sized coil current of relay. Relay will not work and the LED is a warning. There are other equally important types of drawings that are not the subject of this article including logic diagrams, data tables and single line diagrams, wiring diagrams, data communication schematics as well as those single line diagrams that do not significantly address relaying. This point-to-point (publisher/subscriber) list is not maintained by a computer on the Ethernet network, but instead a protective relay engineer uses a System Configurator software tool to program each IED to subscribe to each other  depending on the protection scheme. Most relays make an audible click when triggered, and most relay modules have a LED wired into each relay circuit so you can tell at a glance whether the relay is on or off. “a relay whose function is to detect defective lines or apparatus or other power system conditions of an abnormal or dangerous nature and to initiate appropriate control circuit action” IEEE 100, 2000. Another approach, shown in Figure 8, is to show all the available relay inputs and outputs in a graphical form on one drawing. The 12v adaptor is used for powering the circuit. Several are proprietary and for that reason, one must reference the vendor manufacturer’s relay manuals for schematic representation methods. Very Inverse Relay. If secondary fuses are used, their location and size would also be shown. Overcurrent Relay (+) (–) 52a I Circuit Breaker Trip Coil and Auxiliary Contact. diagram, the protective relay will actuate a contact that will tell the motor’s control circuitry to cut power to the motor in the event of a ground fault. Relay element. In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker when a fault is detected. Additional information will be required on this drawing if it is needed to detail exact functions that are in use. 1. 0 – Z. 3. The Power Supply Unit interfaces with a stepped down AC voltage from the AC power line and can be subjected to current overloads and voltage transients such as transients induced by lightning. It is imperative that an external fuse be connected as shown on the "WIRING DIAGRAM FOR MODULE XPS-AK SAFETY RELAY… It is possible for one IED to communicate the same protective message to several other IEDs at the same time. Relay elements in step distance schemes Use positive-sequence impedance in step distance schemes Three relay elements are needed for detecting multiphase or single-phase-to-ground faults k = (Z. cases, the protective relay may trip a circuit breaker directly, or according to the coil rating and the number of circuits to be energised, may do so using a MVAJ tripping relay. The terminal diagram shows in a simplified way the functioning of the protective relay and the external connection of the relay. Logic diagrams are a graphical display that shows what is happening in the logic of the relay or communications system. In reverse polarity protection, there is no output in the wrong connection. 12. In this example, a schematic when a Tie-relay close circuit is energized is shown. 469 0 obj <>/Filter/FlateDecode/ID[<2C37F12B25C46B44A211AC14781101C7><7656337D71E2D84ABE4C15A505A8AFAD>]/Index[460 15]/Info 459 0 R/Length 68/Prev 1277966/Root 461 0 R/Size 475/Type/XRef/W[1 3 1]>>stream For the fault shown, the fuse F1 should respond very fast to this fault, as this fuse is the primary protective device of this zone. When microprocessor relays are used, internal relay program parameters will determine how secondary input quantities will be measured as well as the directional sensitivity of specific elements. AC Schematics, which are also called AC Elementary Diagrams or Three Line Diagrams, will show all three phases of the primary system individually. Title: CONNECTION DIAGRAM RELAY FT1 Created Date: 4/14/2014 10:29:03 AM Here current test switch 6 TC clearly shows the terminal point number and what each test switch does on operation. The difficulty in this alternative is distinguishing between hardware connections, which feature physical contacts, and the logic, which depicts logical outputs as contacts. This includes AC schematics and DC schematics and diagrams that prominently feature relaying. 7.5 PW205 PW205 20 25 15 18.5 PW305 PW405 PW305 PW405 30 White It will protect the AC motor burn out. This circuit can be used for isolating only one speaker. The relay in the circuit has a coil rated for 9 VDC and a switch rating of 10 A at 117 VAC. For testing purpose we have used Buzzer and LED as a output actuator. The general layout of these drawings is that the DC source is usually shown at the left end of the drawing and the initiating contacts are shown above the operating elements. Now in the diagram below I have added a motor starter. The diodes are simultane- ously responsible for performing rectification, freewheeling and polarity reversal protection functions. Relay K1 must be an SPDT relay; Voltage rating of the SPDT relay must be selected according to the supply voltage of your amplifier. As the experience in using these drawings grew, practices common throughout the industry arose while at the same time utilities developed many standards regarding the details of the elementary wiring diagram that works best for them. a trip output contact from one relay to the input coil of another relay). In addition to showing the specific contacts that are used in the design, labels could be used that may show small details regarding the contact such as ‘51’ for overcurrent relay contact. However, 13 is also used in the physical design shown in the wiring diagrams. Metering information generally required for utility operations may include voltage, current, power (both Watts, and Vars) as well as other values. If complexity of the system requires it, the devices controlling the equipment, like the two relays featured in Figure 4, may be shown on one drawing. This level of detail is needed to insure that testing can be done easily and avoids errors while testing. vdc 86/94-1_trip relay pos. Here is a schematic diagram for a simple circuit that uses a 9 VDC circuit with a handheld pushbutton to turn a 120 VAC lamp on and off. How Do Instantaneous Relays Work? The placement of a flyback protection diode is rather simple; it should be placed directly across the relay's coil. Below given is Relay Driver Circuit to build your own Relay module: Circuit Diagram and Working: In this Arduino Relay Control Circuit we have used Arduino to control the relay via a BC547 transistor. Rapid pump start protection cut out over 12 start/hour LED status Calibration Tank control (float switch) *TEOI/S version only For multiple pump applications, CONNECTION DIAGRAM TO Connection diagrams vary for Other voltages CT required where FLC exceeds IOA use one relay per pump. Near the center of the figure is the number 13 just above the text “79 “NLR21U”. Saved from bernini-design.com. One of the more common forms is the differential current relay. The equipment being controlled would show up in another drawing, such as the switcher in Figure 5 below. If metering functions are to be included in a microprocessor relay these functions could be indicated on the AC schematic drawing or even the single line diagram. The basis of the problem is the design of the protection system has moved from a hardware based system to a software based system with little experience in the best methods to document these designs. IEC 61850 provides a method for relay-to-relay interoperability between IEDs from different manufacturers. Protective relays that are applied to monitor changes in the AC system will be shown on the AC schematic connected to current and voltage transformer secondary outputs. Circuit diagram. The basic function of a protective relay is to identify the fault and isolate faulty part from the healthy part of the system. The repetition of 13 is not needed on this schematic to communicate that all these points are electrically the same, this fact can be easily seen in the drawing. The coil current can be on or off so relays have two switch positions and most have double throw (changeover) switch contacts as shown in the diagram. Notes Notes 1 Inrush current is a factor with every motor type, AC or DC. The alternatives that will be briefly discussed include hardware only documentation, software shown as part of the traditional elementary diagram, and showing a logic diagram on the elementary. 1) / (3Z. Time-overcurrent relay . It should be noted that sometimes the control functions are supplied by AC and are included in the elementary diagram (refer to Figures 6 and 8). We have connected transistor base to Arduino pin A0 through a 1k resistor. Figure 6 (see below) shows the one line diagram as well as the protective device coordination chart. LM7805. Study specialized technical articles and papers. Evolving Protective Relay Designs • Electromechanical relays • Electronic analog relays – solid state (transistors, integrated circuits) • Microprocessor-based relays – digital or numeric . For example, in Figure 6 we see that FU-1 is rated at 20A, that HTR2 is rated for 300W at 240V and that a 7500Ω resistor is needed when connected to 250VDC. Overall and mounting dimensions (mm) XJ3-G, S wiring diagram XJ3-D wiring diagram Live Demo for Over Current Protection: https://youtu.be/lqO32VIFvP0Whatsapp No : +91-9818947641Buy From AmazonVoltage protection Adjustable (New Ver.) This is sourced from from ​ the Project Description document provided by Black & Veatch. endstream endobj startxref A protective relay circuit. DIY learn : How to make short circuit protection circuit using relay for 6v battery safety thank you. The protective relay equipment 12 includes a green indicator light 40 which is illuminated when the H.E.A. distance relay response characteristic, when presented on an R-X impedance diagram, will have an operating area dependent on the manner in which the input quantities are processed and compared. Present microprocessor relays are often capable of providing this information with acceptable accuracy. Protective Relays Protective relay work as a sensing device, it senses the fault, then known its position and finally, it gives the tripping command to the circuit breaker. a bus differential relay would subscribe to all associated feeder protection relays on that bus, or a main-tie-main relay group would subscribe to each other to perform breaker interlocking). 1: One-line protection schematic Logic schematics can be drawn to illustrate how different protection elements are wired. December 2020. As utilities have gone through some corporate changes through the years such as merging various companies, the selection of a common standard can often be a challenging process. It's using relays to control the circuit and also the diagram will begin to take the shape of a ladder as the relay logic grows. 21 : (4) A protective relay in which the response to the input quantities is primarily a function of the electrical circuit distance between the relay location and the point of fault. Differential relaying provides selectivity by providing a zone of protection with a circuit of interconnected CT’s. In an over current relay or o/c relay the actuating quantity is only current.There is only one current operated element in the relay, no voltage coil etc. Such type of relay is used in the feeder and on long transmission lines. A relay is an electrically operated switch.Current flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts. Good material and explanations, Thanks for propagating technical ,very useful information, Thanks for all very educative materials, it help to build up my technical skills on the electrical/electronic fields. Note that 13 is repeated to the right next to the contact labeled R2 and to the left next to the contact labeled C1. ... the sequence diagrams would be connected in series as shown. Protective Relay A protective relay is a device that detects the fault and initiates the operation of the circuit breaker to isolate the defective element from the rest of the system. Documentation of the logic in microprocessor relays adds one level of challenges and the advent of schemes that use relay to relay communication connections and protocols, such as IEC 61850, add another level of challenges. A schematic for a freewheeling diode circuit in a relay is shown below. Terminal blocks will be marked with this number and in this application, it is an indication that all the points are electrically the same and can be identified by the same 13 on this schematic. Power Supply Unit . Nominal secondary current rating (commonly either 1A or 5A) will also be shown along with secondary wire names, for example C1, C2, C3, and C0 for the set of CTs connected in a wye configuration on Figure 1. 1. 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