UL 1562-2013 pdf download

UL 1562-2013 pdf download.Transformers, Distribution,Dry-Type -Over 600 Volts.
13 Conformance Tests
13.1 The transformers shall comply with the test requirements listed in Table 9 of the American National
Standard for Transformers — Used in Unit Installations. Including Unit Substations — Conformance
Standard, ANSI C57.12.55.
14 Transient Voltage Analysis Test
14.1 The insulation of a transformer shall be capable of withstanding the voltage stress imposed under impulse conditions.
14,2 In order to identify the points of maximum stress, the nonlinear distribution of the wave shape from turn to turn, layer to layer. section to section, and the like, is to be determined using differential measurements while a 1.2 x 50 microsecond low voltage wave shape Is established across the winding.
14.3 A full size model of one coil of a transformer subjected to the tests in Conformance Tests, Section
13, is 10 be subjected to the transient voltage analysis test. The coil is to be tested as part of the
transformer or under concMions that simulate the ground frame of the enclosure, core and adjacent coils.
The coil is to be constructed with leads connected to test points that are not accessible with a probe. Test
leads are not to be larger that 20 AWG and should be kept as short as possible.
14,4 The specified wave shape is to be imposed across the coil and differential voltages at the test points are to be measured. Each test point is to be numbered on a schematic drawing of the test coil identifying the number of turns to that point. The voltage between each pair of test points is to be indicated in the test log.
14.5 At each test point, the voltage stress that would appear under full impulse condition is directly proportional to the measured test voltage. This value is to be computed from the direct relationship between the rated BIL and the measured voltage at each test point. The transformer insulation at each test point shall be capable of withstanding the voltage stress.
15 Transformers Supplied With a K-Factor Rating
15.1 A transformer marked with a K-factor rating in accordance with 17.3 shall be loaded with a nonsinusoidal load having a K-factor of no less that the K-factor rating of the transformer.
Exception: The frans former may be tested by the loading-back method, the impedance RVA method, the actual (resistance) method, or the short circuit (separate load loss and excitation test) method in accordance isth the IEEE Standard Test Code for Dry- Type Distribution and Power Transformers, C57. 12.91 provided the load is adjusted to compensate It harmonic losses in accordance with 15.2.
15.2 With regard to the exception of 15.1, the transformer load losses (PLL) are to be determined as follows:
15.3 With regard to the transformer load losses (PLL) determined in 15.2, during the conduction of the temperature test, the load losses are to be monitored as indicated below (reference the IEEE Standard Test Code for Dry-Type Distribution and Power Transformers, C57,12.91):
a) If the loading-back method is used, the load losses are to be monitored at the loading source of the loading transformer
b) If the Impedance kVA method Is used, the load losses are to be monitored at the source for the impedance loss.
c) If the short-circuit method is used, the load losses are to be monitored at the ezcited windings during the conduction of the short circuit portion of the test.
d) If the actual (resistance) method Is used, the load losses are to be monitored as the difference between the measured input power and the measured Output power,
16 PartIal DIscharge Test
16.1 Deleted
16.2 Deleted
MARKING
17 General
17.1 Transformers shall be marked in accordance with Section 8 of the American National Standard for Transformers — Used in Unit Installations, Including Unit Substations — Conformance Standard. ANSI C57. 12.55.
17.2 A transformer provided with ventilation openings shall be marked where visle after installation, Do not install closer than _____ inches to surrounding surtaces.” or an equivalent wording. The blank space is to be filled in by the manufacturer to specify the minimum clearance necessary.
17.3 A transformer intended for use with loads drawing non sinusoidal currents may be marked ‘Suitable for nonsinusoidal current load with K-factor not to exceed . The blank shall be filled in with the K-factor rating ol 4, 9, 13. 20, 30, 40, or 50.