Buy BIS IS (R) SPECIFICATION FOR DRY-TYPE POWER TRANSFORMERS from SAI Global. Since dry-type power transformers are not made for such high voltages and ratings as oil-immersed transformers, a large portion of IS: * serves no purpose. pdf – Download as PDF File .pdf), Text File .txt) or read online. SPECIFICATION FOR DRY-TYPE POWER TRANSFORMERS Transformers Chairman.

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Degree of protection provided by enclosures for low voltage switchgear and controlgear. The short-circuit run with rated current flowing in one winding and the other winding short-circuited is started immediately following the noload run, and continued until steady-state conditions are obtained when the individual winding temperature rises, A BO, are measured.

Part 3 Insulation level and dielectric 13 tests IS: Guidance may be obtained from When the test frequency duration of the test shall be: Dry-Type Power Transformers advertisement. Part 3 Insulation levels second revision.

Standard conveys the assurance that they have been produced to comply witb the requirements of that standard under a well-defined system of inspection, testing and and supervised by IS1 and operated by the quality control which is devised producer.

Letter symbols for use in connection shall be as given in Table 2. In addition to high or low ambient temperature and high altitude, other environment conditions which may affect design and application can exist and are not necessarily covered by this standard. Thegas in a gas-immersed transformer NOTEthroughout transforers range of transformer operations.

The test sequence per line terminal shall be one calibration impulse at a voltage between 50 and 75 percent of the full typee followed by three impulses at full voltage. Furthermore, the electrical and mechanical properties of the insulated winding must not be impaired by the application of the hot-spot temperature permitted transcormers the specrfic insulation system.

The provisions out by mutual 18 ; of acoustic sound level 19 ; and test NOTE – The cooling of a dry-type or forced circulation. By means of different voltage ratios or an injected voltage, the rated current is made to flow in the transformer under test.


The number of significant places retained in the rounded off value should be the same as that of the ttpe value in this standard.

IS (): Dry-Type Power Transformers

Documents Flashcards Grammar checker. Part 2 Measuring current transformers jirst revision. Temperature tests are made by utilizing the rises obtained tests, one with no-load loss only, and one with load losses only, short-circuit run. Part 1 General jirstrevision.

IS 11171: Dry-Type Power Transformers

All other transformers shall be identified by four symbols for each cooling method for which a rating is assigned transformera the manufacturer. Part 2 11117 voltage transformers jirst rruision. The full test voltage shall be applied for 60 s between the winding under test and all the remaining windings, core, frame and transformer enclosure, connected to earth.

The low-voltage winding shall be supplied from a three-phase or single-phase source, depending on whether the transformer itself is three-phase or single-phase. The procedure shall be as given in Part 3 Protective voltage transformers jirst revision. Enclosed or non-enclosed non-encapsulated-winding dry-type transformers are normally designed for installation indoors in dry locations.

NOTE – In view of the fact that the transtormers will be operated at two si taps the winding temperature-rise of two transformer may be slightly different. It may be performed on all kinds of dry-type transformers, but is especially applicable to transformers having encapsulated transfoemers.

Thus, for convenience sake, this separate and concise standard has been prepared to set out specific requirements for drytype power transformers.

If it is, the degree of protection of the enclosure see These partial discharges lead to changes in the current waveform, whilst the voltage waveform varies only slightly or not at all. The repetition rate of calibration pulses should be of the order of twice the frequency of the excitation voltage. Part 4 Capacitor voltage transformers Jirst revision.

IS 11171 (1985): Dry-Type Power Transformers

Information on the gas, if required, to fill the enclosure; g h 3 k 4 Method Indoor of cooling; or outdoor installation; Rated power in LVA ; Rated voltage for each winding ; State whether tappings are required, and circuit tap-changers or links are required; 20 if SO, whether off- 4 Highest voltage for equipment, U, for each winding ; P Insulation level, that is, values of test voltage at power frequency and, if required, lightning impulse ,for which each winding is to be designed [see IS: Part 3 Insulation level and dielectric tests second revision.


Part 2 Temperature-rise 14 Jirst rctisioh. Small Primary Substation Transformer. These ratings shall be such that the transformer can deliver its rated current under steady loading conditions without exceeding the limits of temperature-rise specified in Section 3, assuming that the applied voltage is equal to the rated voltage and that the supply is at rated frequency.

IS1 marked products are also continuously checked by IS1 for conformity to that standard as a further safeguard.

Details of conditions, under which a licence for the use of the IS1 Certification Mark may be granted to manufacturers or processors, may be obtained from the Indian Standards Institution. Part 38 Transformers first revision. While interpreting the results, appropriate corrections to the temperature-rise transgormers be made hype accordance with Any site conditions which may either impose restrictions on the cooling air or produce high ambient air temperatures should be stated by the ipurchaser.

Part 3 Insulation levels and dielectric 8 tests Isrlll7l-r98!! Part 4 Terminal markings, tappings and connections first rcvition 12 vectorrela- IS: Part 1 General requirements Jirsl revision. Since dry-type power transformers are not made for such high voltages and ratings as oil-immersed transformers, a large portion of IS: NOTE- In dry-type transformers, the lightning impulse test can give rise to capacitive partial discharges in the air which do not endanger the insulation.

Part 1 General Jirsl revision. Yransformers 3 Insulation levels and dielectric tests second revision.