Pickup is defined as that value of current or voltage which will just close the relay contacts from. Apparatus testing, scada testing, relay testing, function testing, load angle readings to verify correct power flow. Always refer to the suppliers data for the object under test and follow the guidance it contains on testing. Apprentice electrical technician test ett about the test there are 40 questions with a maximum time limit of three hours. The following sections of the ansineta standard for acceptance testing specifications for. This is the most comprehensive guide about motor relay testing and dynamic relay testing. Circuit breakers equipped with solidstate trip devices can be tested using secondary current injection, which requires less time and expense to perform the. Page 3 of 15 standard work practice sp0518 ver 2 ergon energy corporation limited abn 50 087 646 062 ergon energy queensland pty ltd abn 11 121 177 802 return the relay scheme to service in an acceptable standard.
Operation and maintenance of protective relays and. Ge power management technical publication, relay testing and maintenance, document number. Protection systems play a key role for the safe and reliable operation of todays electricity power systems. As relay diagrams show, when a relay contact is normally open no, there is an open contact when the relay is not energized. Properly working protection devices help to maintain the safety of the system and to safeguard assets from damage. Remove any corrosion on battery terminals with bicarbonate of soda. Requires a thorough understanding of relay phasor angle referencing often subject to or controlled by relay settings take care when interpreting the metered values to assure correct phase identification dc control wiring electrically tested while function testing the relay. Installation of protection relays at site creates a number of possibilities for errors in the implementation of the scheme to occur. Relays control one electrical circuit by opening and closing contacts in another circuit.
Two types of relay technology are available, mechanical and solid state. Further, our process expertise also allows us to ensure that end testing service standards delivered by us are as per the parameters followed in our. Inspection, testing and commissioning of electrical. Which of the procedures described below are added to your test plan will depend on the specific. These contacts in turns close and complete the circuit breaker trip coil circuit hence make the circuit breaker tripped for disconnecting the faulty portion of the electrical circuit from rest of the healthy circuit. When the relay is operating correctly the electrical current through the pulldown coil produces a magnetic field that either opens or closes the contact point within the relay depending on its design.
The protective relay maintenance distribution course is an intensive, handson, lab oriented presentation. Standard for maintenance testing specifications for electrical power equipment and systems is the most current revision of this document. This compilation is not intended as a complete survey of the field of electrical and electronic equipment testing. Operation and maintenance of protective relays and associated. Section 7 of the ansineta standard for acceptance testing specifications for electrical power equipment and systems may be reproduced and used on a cut and paste basis for the particular type of equipment to be tested.
Rather, it presents a sampling of many diverse activities for the interest of electrical, electronic, and. Inspection of control and relay panel, preparation of test report and cable schedule for substation, power plant, and process plant. Power testing services llc electrical testing, substation. Standard for an electrical preventive maintenance epm program. How to make a series testing board electrical online 4u. Included are test plans, connections, procedures and testing philosophies. Not all relays used in vehicles today are the iso type. Since type testing of a digital or numerical relay involves testing of software as well as hardware, the type testing process is very complicated and more involved than a static or electromechanical relay.
Relays are remote control electrical switches that are controlled by another switch, such as. Testing at higher voltages can yield additional and more useful information about the condition of the test objects insulation, but using a voltage thats too high for a particular test object to withstand can seriously damage it. This is simple diagram of series board but we can not test low resistance appliances electrical devices, however my incoming post will be about the series board for low resistance appliances testing. Solidstate protective relay maintenance, electrical construction and. Emc tests check the impact on the protection relay under test of highfrequency electrical disturbances. Reference materials ett test contains questions on the following. Standard for testing specifications electrical power.
Our experience in advanced utility and industrial relay applications includes. If you come across a noniso relay, be sure to obtain the vehicle specific wiring diagram for the relay before you test or diagnose the circuit. Electrical fundamentals including threephase electricity, phasor diagrams, and fault types relay testing fundamentals including what equipment you need and how to use it the most commonly used testing philosophies, and the most efficient and effective ones how to translate digital logic used by relay manufacturers into familiar concepts. Commission testing methods for protection systems mipsycon. So it is crucial to test a relay if it stopped working before you replace it or throw it away. A relay usually gets damaged due to a number of reasons. The first electrical test made on the relay should be a pickup test. Facilities instructions, standards, and techniques volume 38 field test procedure for protective relays internet version of this manual created july 2000 facilities engineering branch denver office denver, colorado the appearance of the internet version of this manual may differ from the original, but the contents do not. Emc tests determine the impact on the relay under test of highfrequency electrical disturbances of various kinds. Relays respond to one or more electrical quantities like voltage or current such that they open or close the contacts or circuits. The booklet is excellent for a beginner as well as a seasoned test technician. Acceptance testing, commissioning, and startup will include control power tests, current transformer and potential transformer.
The removal of the connection plug in drawout relays may reveal evidence of severe fault currents or contami. How relays work relay diagrams, relay definitions and relay. Goals and objectives of protection system commission testing. The above diagrams show the terminal configuration and identification of common iso relays. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. Standard for an electrical preventive maintenance epm program page 410 connections. Applications range from classic panel built control systems to modern interfaces between control microprocessors and their power circuits or any application where reliable galvanic separation is required between different circuits. Electrical installation handbook protection, control and. Types of electrical protection relays or protective relays. Grounddistance relay connections, 360 groundfault neutralizer, effect on line relaying, 321 to mitigate the effect of a fault, 2 grounding protective relay for trans former protection, 263 ground preference, 91, 108 ground resistance, 303 groundingtranaformer protection, 268 hsrmoniccurrent restraint, for distance relays. We have done numerous projects consisting of electromechanical relaying, smart grid, relay panels, breaker changeouts, capacitor banks, transformers and various other required substation equipment. Engineers is a group of electrical engineers having a full fledged team offering specialized services in electrical field since 1996. Protection relay testing for commissioning swp check this is the latest process zone version before use. On stranded cable, if ends are corroded, cut off ends or separate strands and clean internally.
This is not intended to be a theoretical document, nor a technical catalogue, but, in. I have been in electrical testing for the past 15 years and have worked for neta shops and utilities. The uses and advantage of series testing board in unlimited and we can use it for many thing. Apprentice electrical technician test ett preparation guide. The relay testing handbook valence electrical training services. In this article, we will show you how to test a relay. A relay is automatic device which senses an abnormal condition of electrical circuit and closes its contacts. I purchased this for a look at anothers perspective on endtoend relay testing. These are operated to open or close the load contacts in response to one or more electrical quantities like voltage and current. Cv engineer electrical testing and commissioning ht, lt, ct. Even if the scheme has been thoroughly tested in the factory, wiring to the cts and vts on site may be incorrectly carried out, or the ctsvts may have been incorrectly installed. It includes everything ive learned about relay testing since the relay testing handbook.
Protection relay guides electrical engineering portal. This seminar will introduce the theory and practice of endtoend relay testing. Working of relayshow relay works,basics,design,construction. The ansineta standard for maintenance testing specifications for electrical power equipment and systems was developed for use by those responsible for the continued operation of existing electrical. The switch may have any number of contacts in multiple contact forms, such as make contacts, break contacts, or combinations thereof. A relay is a switching device as it works to isolate or change the state of an electric circuit from one state to another. Neta international electrical testing association reports show 12% failure rates on protective relays tested. Electrical testing solutions offers complete relay testing services. The participant will learn the basics of distribution protection.
A comprehensive testing program should simulate fault and normal operating conditions of the relay. Relays are switches that open and close circuits electromechanically or electronically. Relays are frequently found device in high voltage or medium voltage power system network. Principles and practice, including stepbystep dynamic testing procedures that can be applied to any relay element with fixedtime delays. Field test procedure for protective relays, may 2011 bureau of. Protection relay testing and commissioning cedengineering. An electrical relay is a remote switch adapted from an electromagnet which uses an electrical current to operate. Should evidence of overheating be found, the insulation should be checked for embrittlement and, where necessary, replaced. Pickup is defined as that value of current or voltage which will just close the relay contacts from the 0. The relay is an automatic protective and switching device which is capable of sensing abnormal conditions in electrical circuits. Department of electrical engineering the ohio state university columbus, ohio. The participant will learn the basics of distribution protection combined with handson, realistic training on actual relays. Relays a relay is defined as an electrically controlled device that opens and closes electrical contacts, or activates and deactivates operation of other devices in the same or another electrical circuit. Standard for acceptance testing specifications for electrical.
Mar 14, 2017 circuit breakers that have thermalmagnetic or electromechanical trip units can only be verified for correct functioning via the primary current injection test method. Nov 22, 2018 in a normal industrial application, periodic testing should be done at least every 2 years in accordance with nfpa 70b 2016. Protective relay testing may be divided into three categories. The relay is a well known and widely used component. Relay maintenance and testing relay startup and commissioning new relay installations require startup and commissioning to ensure proper protection for your system. This is a closed book test and calculators are allowed. Allowing for meter differences, interpretation of readings, etc.
This includes well defined visual and mechanical inspections as well as electrical tests that ensure optimum service standards. Testing and commissioning of all electrical equipment from 415 volts to 2 kv system. A mechanical relay is essentially a combination of. In this chapter, we will learn about one of the basic, but most important components of any electrical system, namely the switchgear.
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