Electrical machines for mechatronics laboratory 2 8 shortcircuit test introduction in the short circuit test, the secondary terminals of the transformer are shortcircuited, and the primary terminals are connected to fairly. Efficiency of a transformer single phase transformer basic. The size of transformers which can be tested will vary with impedance. The connection diagram for the short circuit test on the transformer is shown in the figure below. Short circuit and open circuit tests on transformer can give us. The full load test on a small transformer is very convenient, but on the. Short circuit and open circuit tests on transformer can give us parameters of equivalent circuit of transformer, but they can not help us in finding the heating information. In conducting the sumpner test of transformer the primaries of the two transformers are connected in parallel across the rated voltage supply v 1, while the two secondaries are connected in single phase transformer as shown in fig. The sumpners test requires two identical transformers. A1 by load test,open circuit and short circuit test and sumpners test. This ppt covers the operating principle,its construction,equivalent circuit and efficiency of a single phase transformer. Sumpners test is conducted on transformers to determine a temperature b stray losses. This test gives the value of total loss accurately as it occurs when it is in actual use.
The sumpner test is carried out on two identical transformers to compute the efficiency of each transformer. Open and short circuit test of transformer electrical4u. Sumpners test or backtoback test on transformer electricaleasy. This test gives the value of total loss accurately.
The advantages of three singlephase units are transportation, maintenance, and spare unit availability. Transformers multiple choice questions and answers mcqs electrical engineering interview transformers viva lab manual pdf free download. Polarity test and sumpners test on single phase transformers. Sumpners test is also called as back to back test on transformers because of connections are in parallel at input side and connections are in series. Technologies have developed, and reading sumpner test on single phase transformer manual printable 2019 books can be far easier and much easier. Both the tests let us know about the core losses and copper losses in single phase transformer, then why is sumpners test preferred over open circuit and short circuit test. Sumpners test on a pair of single phase transformers free download as pdf file. To conduct sumpners test on two identical singlephase transformers and to determine its efficiency and regulation characteristics. Which of the following statements regarding an idel singlephase transformer having a turn ratio of 1.
Sumpners test or back to back on single phase transformer theory with circuit diagram,advantages,sumpners test experiment. Sumpners test on a pair of single phase transformers scribd. Single phase transformer single phase dimmer stat ammeter ac. To determine the efficiency and regulation of a given single phase transformer by conducting the oc and sc test and also to draw its equivalent circuit. Electrical diagram of a sumpners test for singlephase transformers 1 by s.
One transformer is loaded on the other and both are connected to supply. Two single phase transformers, two ammeters, three voltmeters, wattmeter. Sumpner s test back to back test on single phase transformer. The maximum temperature rise in a large transformer is determined by the full load test. A voltmeter, wattmeter, and an ammeter are connected in hv side of the transformer as shown. Transformer questions and answers electrical academia.
Sumpner or backtobacktest efficiency of a transformer. Sumpners test in single phase transformer mcqs with answers q1. After observations, the variac is brought to zero position and switch off the. Polarity test of transformer polarity means the direction of the induced voltages in the primary and the secondary winding of the transformer. Sumpners test back to back test on single phase transformer. Open circuit and short circuit tests on single phase transformer. Sumpner test or back to back test on transformer my tech. Single phase transformer and applications of single phase. Concept of coupled circuits, dot convention, writing network equilibrium equations in coupled circuits problems on coupled circuits excluded, principle of transformer action for voltage transformation, constructional details of shell type and core type singlephase and threephase transformers, description of the following types of transformers power transformer. To perform open circuit and short circuit test on a single phase transformer and to predetermine the efficiency, regulation and equivalent circuit of the transformer. While performing sumpners test on transformer, if the secondarys are not in series opposition then the meter will read a. Singlephase transformer cores 2leg core 3leg core 4leg core fig. Sumpners test electrical engineering interview questions.
Test systems equipped with optional high voltage taps will allow testing of transformers with higher. Polarity testing of transformers is vital before connecting them in parallel. However is not viable to conduct this test by connecting the secondary of the transformer to rated load. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
For conducting heat run test on the three phase transformer, full rated. Sumpners test transformers questions and answers sanfoundry. Singlephase transformers transformer symbols n p number of turns in the primary n s number of turns in the secondary e p voltage of the primary e s. Sumpners test back to back test your electrical home. Sumpners test on similar transformers and determination of combined and individual transformer efficiency.
This is a more expensive solution, and it is used in the high voltage power system. Phenix technologies singlephase transformer test systems are designed to provide voltages and currents to test singlephase distribution transformers. The full load test on a small transformer is very convenient, but on the large transformer, it is very difficult. How to do an insulation test of a single phase transformer. Open circuit and short circuit test on transformer. Sumpner s test of single phase transformer is a very exclusive and important product designed for students of electrical engineering to explain the basic concepts of sumpner s test. Sumpners test is used to put large transformer on full load. What is backtoback test sumpners test on transformer.
For lowvoltage applications, the standard is to test at 500 or v, though there are higher voltage meg. The fullload test of large transformers is not possible because considerable wastage of energy occurs and it is difficult to get a suitable load for absorbing fullload power. Other results for sumpner s test viva questions and answers. The threephase system application means using three single phase units connected in the threephase system. Mod01 lec05 lecture05testing of single phase transformers. Load test or back to back test or sumpner s test of. Sumpner test of transformer sumpner test on single phase. These two transformer tests are performed to find the parameters of equivalent circuit of transformer and losses of the transformer. Load test of a transformer is basically carried out for determining the maximum temperature rise of the transformer. If the two transformers are connected in parallel, then the polarity should be known for the proper connection of the transformer. Open circuit test and short circuit test on transformer are very economical and convenient because they are performed without actually loading of the transformer. Theory heat run test is one of the type tests on power transformer. A 60kva single phase transformer with a primary voltage of 2,400 volts and a secondary voltage of 240 volts. Info ebook and manual reference sumpner test on single phase transformer manual printable 2019 best ebook you must read is sumpner test.
Sumpners test or back to back test requires two transformers. What are the advantages of sumpners test over conventional. This test reproduces conditions of continuous rated load and the temperature rise occurring during the load. A low voltage of around 510% is applied to that hv side with the help of a variac i. Sumpners test in singlephase transformer mcqs with answers. With this trainer, students can learn about the significance of conduction of. Sumpners test provides data for finding the regulation, efficiency and heating under load conditions and is employed only when two similar transformers are available. Theory of operation of singlephase transformers definition of transformer an electrical power transformer is a static device, which transforms electrical energy from one circuit to another without any direct electrical connection. The advantage of conducting this test is very economical of power, even when the transformers are tested at full load conditions. This test can also be used to determine the efficiency of a transformer. Load test on singlephase transformer and three phase transformers. To make this resistance test for insulation breakdown. To determine regulation and efficiency of a single phase transformer by open circuit o.
Here, two identical transformers are connected back. Open circuit or no load test on transformer open circuit test or no load test on a transformer is. Testing of single phase transformers oc test sc test sumpner s test or back to back test. This test is called, backtoback test, regenerative test or sumpners test. Why is a megger preferred to an ohmmeter when measuring the insulation breakdown of a distribution transformer. Here, two identical transformers are connected back to back, such that their primaries are in parallel across the same voltage source and. Otherwise, with incorrect polarity, it is not possible to connect them in parallel. This test is called, backtoback test, regenerative test or sumpner s test. Backtoback test sumpner s test on transformer definition. Load test or back to back test or sumpners test of transformer.
Polarity test of a singlephase transformer electrical. While performing sumpner s test on transformer, if the secondarys are not in series opposition then the meter will read a. Sumpners test back to back test the sumpners test is another method of determining efficiency, regualtion and heating under load conditions. Sumpners test give more accurate results of regulation and efficiency than o. Sumpners test give more accurate results of regulation. Depends on the voltage rating of the transformer, but typically a megger is used to test primary to secondary, and each winding to ground.