File Ref: CT235009EN Effective April 2020 COOPER POWER New Issue SERIES

UltraSIL™ Polymer-Housed

VariSTAR™ Type U3AF Class SM Station-Class Surge Arresters certified test report

CT235009EN Page: 2 of 19

UltraSIL™ Polymer-Housed

VariSTAR™ Type U3AF Class SM

Station-Class Surge Arresters

CERTIFICATION

Statements made and data shown are, to the best of our knowledge and belief, correct and within the usual limits of commercial testing practice.

Timothy Smith Michael M. Ramarge

Principal Engineer Manager of Product Engineering - Arresters

CT235009EN Page: 3 of 19

INTRODUCTION

This test report certifies that the UltraSIL™ Polymer-Housed VariSTAR™ Type U3AF Station-Class Surge Arresters were successfully tested to IEC60099-4™-2014 standard " Metal-oxide surge arresters without gaps for a.c. systems”

TEST PROGRAM

OBJECT To demonstrate that the UltraSIL Polymer-Housed VariSTAR Type U3AF Station-Class Surge Arresters meet all performance requirements.

PROCEDURE The following design tests were performed on a sufficient number of samples to demonstrate all performance requirements are met.

TYPE TESTS Test Description Per IEC60099-4 ™-2014 section A. Insulation Withstand test 10.8.2 B. Residual Voltage test 10.8.3 C. Test to verify long term stability under continuous 10.8.4 operating voltage D. Test to verify the repetitive charge transfer raring, Qrs 10.8.5 E. Heat dissipation behavior of test sample 10.8.6 F. Operating duty test 10.8.7 G. Power-frequency voltage versus time test 10.8.8 H. Short-circuit Test (Design A) 10.8.10 I. Test of the bending moment 10.8.11 J. Weather ageing test 10.8.17

RESULTS UltraSIL Polymer-Housed VariSTAR Type U3AF Station-Class Surge Arresters met all performance requirements.

CT235009EN Page: 4 of 19 TEST A INSULATION WITHSTAND

Report Number B8025339 and C0005947 Certifying Laboratory CESI

OBJECTIVE The voltage withstand tests demonstrate the voltage withstand capability of the external insulation of the arrester housing.

PROCEDURE Samples of the longest unit were tested to represent arresters < 245kV, the results are detailed in report B8023734. The internal parts of the arrester were removed to permit these tests. The housing of polymer-housed surge arrester was arranged for the tests with an insulating support as provided by the client. Four shorting wires connected the head of the insulating support to its base. The base of the insulating support was connected to the earth of the test laboratory. The outside surface of housing of polymer-housed surge arrester was cleaned. The test voltage was applied between the upper line terminal of the arrester housing and its end terminal connected to the insulating support and earth.

Lightning impulse voltage test (dry) The housing of polymer-housed surge arrester was subjected to a standard lightning impulse voltage dry test according to IEC 60060-1 and IEEE Std 4. The applied voltage was the specified withstand voltage shown in Table 1 below. Fifteen consecutive impulses at the specified test voltage value were applied for each polarity.

Power-frequency voltage test (dry and wet) The housing of surge arrester was subjected to a power-frequency withstand voltage test in dry and wet conditions. For wet conditions the characteristics of the rain were according to IEC 60060-1 and IEEE Std 4. The applied voltage was the specified withstand voltage shown in Table 1 below.

Table 1 Withstand Voltage kV peak Ring Size (mm) None 660 1067 Lightning impulse withstand voltage (dry) 635 617 513 Switching impulse withstand voltage (wet) 527 534 428 Power-frequency withstand voltage (dry) 375 344 304 Power-frequency withstand voltage (wet) 288 317 240

CT235009EN Page: 5 of 19 Insulation withstand tests were carried out on a complete arresters assemblies and equipped with the complete external grading system. This represents arresters >245kV, the results are detailed in report C0005947 The internal parts of the arrester were removed to permit these tests. The test voltage was applied between the line terminal and the earthed base. The arrester for the tests has been placed on pedestal (Height=1800mm)

Lightning impulse voltage test (dry) The housing of polymer housed metal-oxide surge arrester was subjected to a lightning impulse voltage test in dry conditions following the measurement practices in accordance with the specification as given in IEC 60060-1. Fifteen consecutive impulses of 910kVpeak were applied, for each polarity, between the arrester line and ground terminals. The applied voltage was determined by multiplying the specified withstand voltage by the correction factor taking into account air density and humidity at the moment of the test (as per IEC 60060-1).

Switching impulse voltage test (wet) The housing of polymer housed metal-oxide surge arrester was subjected to a switching impulse voltage test in wet conditions following the measurement practices in accordance with the specification as given in IEC 60060-1. Fifteen consecutive impulses of 872 kVpeak were applied, for each polarity, between the arrester line and ground terminals. The applied voltage was determined by multiplying the specified withstand voltage by the correction factor taking into account air density at the moment of the test (as per IEC 60060-1). The characteristics and the parameters of the artificial rain were according to the procedure given in IEC 60060-1.

RESULTS No disruptive discharges occurred for any test Therefore the housing of the surge arrester passed the lightning impulse, switching impulse and power frequency voltage tests The insulation withstand value for VariSTAR Type U3AF are shown in Table 2 .

CT235009EN Page: 6 of 19 TEST B RESIDUAL VOLTAGE TEST

Report Number B9011514 Certifying Laboratory CESI

OBJECTIVE To determine the maximum residual voltage characteristics of the arresters with various waveforms.

PROCEDURE Sample arresters were impulsed using the following wave shapes; Lightning impulse residual voltage test wave-shape 8/20 μs peak current 40 kA Switching impulse residual voltage test wave-shape front time in the range 30μs to 100μs, tail time twice the virtual time peak current 2000 A (according to table 1 of the reference standard) Steep current impulse residual voltage test wave-shape front time equal to 1 μs, tail time less than 20 μs peak current In = 10 kA (according to the reference standard)

The residual voltage crest was measured.

RESULTS Table 3 shows the maximum residual voltages for the VariSTAR Type U3AF Station-Class Surge Arresters.

CT235009EN Page: 7 of 19 TEST C TEST TO VERIFY LONG TERM STABILITY UNDER CONTINUOUS OPERATING VOLTAGE

Report Number B9012279 Certifying Laboratory CESI

OBJECTIVE Demonstrate that the power loss factor remains stable during ageing .

PROCEDURE Measure the Power Loss factors Pstart,, Pmin and Pend from VariSTAR samples of the 76 mm nominal diameter that were energized at the specified power-frequency voltage for a total duration of 1000 hours while maintained at the temperature of 115 °C. During the ageing period the following criteria have to be met: -any increase of power losses from Pmin was not greater than 1,3 times Pmin for each MO resistor -all measurements of power losses including the final measurement was not greater then 1,1 times Pstart

RESULTS The acceptance criteria were fulfilled and therefore the test result is positive

CT235009EN Page: 8 of 19 TEST D TEST TO VERIFY THE REPETITIVE CHARGE TRANSFER RATING Qrs

Report Number B9011518 Certifying Laboratory CESI

OBJECTIVE The purpose of this test is to verify the repetitive charge transfer rating, Qrs, of an arrester. Repetitive charge transfer capability is specified as an impulse current stress that can be withstood by the MO resistors of an arrester twenty times without mechanical or unacceptable electrical damage.

PROCEDURE

Ten VariSTAR samples of the 51 mm nominal diameter with the greatest nominal length used in the arrester design with the highest residual voltage at the classifying current that is used in the design. Measurement of the lightning impulse residual voltage at the nominal discharge current and the power frequency reference voltage at the reference current. Calculation of the corrected values of Qrs associated to each test sample according to clause 7.3.1 of the reference standard. Application of twenty long-duration current impulses with approximately rectangular waveshape (virtual total duration from 2ms to 4 ms) delivered in ten groups of two operations each. The interval between consecutive impulses of the same group has been about 60 seconds. Between different groups the samples have been let to cool down to near ambient temperature. Measurement of the power frequency reference voltage at the reference current and the lightning impulse residual voltage at the nominal discharge current for comparison with initial value. Application of a current impulse 8/20 μs of an amplitude resulting in a current density of 0,5 kA/cm2 Visual inspection

RESULTS VariSTAR Type U3AF Station-Class Surge Arresters met the charger transfer rating of 1.6 C as claimed with ten samples passing the requirements of 20 impulses, <5% change in residual voltage and reference voltage, and no physical damage.

CT235009EN Page: 9 of 19 TEST E HEAT DISSIPATION BEHAVIOR OF TEST SAMPLE

Report Number B9011517 Certifying Laboratory CESI

OBJECTIVE

For tests involving thermal recovery in which prorated arrester sections are used, it is required that the sections are thermally equivalent to the complete arrester. If, at any time, the measured cooling curve of the section falls below the measured cooling curve of the complete arrester, compensation must be made by adding a factor, k, to the relative overtemperature, Trel, such that the cooling curve of the section is at or above the cooling curve of the complete arrester over the entire cooling period

PROCEDURE

The following procedure was followed to demonstrate this equivalency. The first test on the complete arrester followed by a test on the prorated section.

Test procedure on complete arrester The complete arrester was placed in the testing laboratory at still air ambient temperature of 29,8 °C. The ambient temperature was held at 29,8 °C ±3K during the test . The complete arrester was fitted with three optical thermal sensor attached to the MO resistors The surge arrester was heated to a temperature of approximately 140 °C by the application of a power frequency overvoltage with an amplitude above the reference voltage. The heating time was 51 min. When the specified temperature of about 140 °C was reached the voltage source was disconnected and the cooling time curve was determined over a period of 2 hours.

Test procedure on thermally prorated section The thermally prorated section was placed in the testing laboratory at still air ambient temperature of 30,2 °C. The ambient temperature was held at 30,2°C ± 3K during the test . The prorated section was had one thermocouple type J The prorated section with only one MO resistor was heated to a temperature of approximately 140 °C by the application of a power frequency overvoltage with an amplitude above the reference voltage. The heating time has been of 49 min. When the specified temperature of about 140 °C was reached the voltage source was disconnected and the cooling time curve was determined over a period of 2 hours.

RESULTS The cooling curve of the arrester section was for all instants equal or higher than the cooling curve of the arrester. Therefore compensation is not necessary.

CT235009EN Page: 10 of 19 TEST F OPERATING DUTY TEST

Report Number B9014219 Certifying Laboratory CESI

OBJECTIVE The purpose of this test is to verify the arrester’s ability to thermally recover after injection of the rated thermal energy, Wth, , under applied temporary overvoltage and following continuous operating voltage conditions. Each design of arrester shall be assigned either a thermal energy rating, Wth

PROCEDURE

Test performed on Polymer-housed metal-oxide surge arrester section in open air

Initial test a) Measurement of the lightning impulse residual voltage at the nominal discharge current b) Measurement of the power frequency reference voltage at the reference current

Conditioning c) Application of two high current impulse 4/10 μs at 100 kA with cooling to ambient temperature before second application

Test performed on Polymer-housed metal-oxide surge arrester section assembled in thermal model

Thermal recovery test d) The surge arrester sections were kept in an oven at the temperature of 62,0 °C till thermal equilibrium e) Injection of three long-duration current impulses of 3.9 ms, each at one third the rated thermal energy Wth of 7.2kj/kV Ur. The interval between the impulses was less than 60s. At a time shorter than 100ms after the application of the three long duration current impulses the sample was energized at Ur’ for 10s and then at Uc’for 30 min. to verify the thermal stability.

Test performed on Polymer-housed metal-oxide surge arrester section in open air f) Measurement of the lightning impulse residual voltage at nominal discharge current for comparison with initial value

RESULTS The visual inspection of the sample after the test has revealed no sign of physical damage. The variation of lightning impulse residual voltage before and after the test was less than 5% The thermal recovery was achieved. The acceptance criteria are fulfilled. The test result is positive

CT235009EN Page: 11 of 19 TEST G POWER-FREQUENCY VOLTAGE VERSUS TIME TEST

Report Number B9013191 Certifying Laboratory CESI

OBJECTIVE The purpose of this test is to demonstrate the TOV (temporary overvoltage) withstand capability of the arrester. In this test, the TOV is strictly a power-frequency overvoltage for time periods from 0,1 s to 3 600 s. The published curves and tables shall include data “without prior duty” and “with prior duty”.

PROCEDURE Test performed on Metal-oxide resistors section in open air Initial test a) Measurement of the lightning impulse residual voltage at the nominal discharge current b) Measurement of the power frequency reference voltage at the reference current

Test performed on Metal-oxide resistors assembled in thermal model Test with energy input (prior duty test) c) The surge arrester sections were kept in an oven at the temperature of 62°C till thermal equilibrium d) Three long-duration current impulses of 3.9 ms at the rated thermal energy Wth . At a time shorter than 100 ms after the application of the second impulse, the sample was energized at the overvoltage UTOV for a time tTOV (declared by the manufacturer) and then at Uc‘ for 30 min. to verify the thermal stability.

Four samples were tested as specified below: Sample UTOV TOV1 1,077 x Ur’ 1 sec TOV2 1,019 x Ur’ 10 sec prior duty test TOV3 0,962 x Ur’ 100 sec TOV4 0,904 x Ur’ 1000 sec

Test without energy input (no-prior duty test) e) The surge arrester sections were kept in an oven at the temperature of 61°C till thermal equilibrium f) Application of the overvoltage UTOV for a time tTOV and then at Uc‘ for 30 min. to verify the thermal stability.

Two samples were tested as specified below: Sample UTOV TOV5 1,123 x Uc’ 10 sec no-prior duty test TOV6 1,008 x Uc’ 1000 sec

Test performed on Polymer-housed metal-oxide surge arrester section in open air g) Measurement of the lightning impulse residual voltage at nominal discharge current for comparison with initial value

RESULTS The visual inspection of the sample after the test has revealed no sign of physical damage. The variation of lightning impulse residual voltage before and after the test was less than 5% The thermal stability was achieved. The acceptance criteria are fulfilled for the curves shown in Figure 1

CT235009EN Page: 12 of 19 TEST H SHORT CIRCUIT TEST (POLYMER-HOUSED ARRESTER DESIGN A)

Report Number 2251-16 Certifying Laboratory KEMA

OBJECTIVE To verify that the pressure-relief capability of VariSTAR Type U3AF Station-Class Surge Arresters meet the requirements in accordance with section 10.8.10 The test is performed in order to show that an arrester failure does not result in a violent shattering of the arrester housing, and that self-extinguishing of open flames (if any) occurs within a defined period of time.

PROCEDURE 144 kV rated samples were used in the testing for this design. The arrester samples were mounted to simulate service conditions as specified by the standard. A minimum of four are required. One or two for rated-current test and one for each of the two reduced current tests. Samples were set to fail via the use of 0.4 mm dia. Copper wire on the surface of the block column at the gas channel side such that the wire melts within the first-30 electrical degrees after initiation of the test current.

High-Current Pressure-Relief Testing: The test circuit was adjusted to produce a 60 Hz, rms current as designated below for a minimum of 0.2 seconds. 63 kA for 0.2 s 25 kA for 0.2 s 12.5 kA for 0.2 s The noted current was initiated within 5° of the applied 60 Hz voltage zero. The arresters were monitored to assure venting occurred without violent shattering.

Low-Current Pressure-Relief Testing: The test circuit was adjusted to produce a 60 Hz current of 600 A (+/-200A) determined by the average for the duration of the current flow. 600 A for 1 s The current duration lasted until the arrester vented up to a maximum of 1 second or until venting occurs.

RESULTS VariSTAR Type U3AF Station-Class Surge Arresters passed the described high and low-current pressure- relief tests based on oscillograph recordings showing test current magnitude and duration, from the evidence of the time at which the venting occurred, and from the confinement of all components of the arrester within the specified enclosures.

CT235009EN Page: 13 of 19 TEST I TEST OF THE BENDING MOMENT

Report Number C00001338 Certifying Laboratory CESI

OBJECTIVE This test demonstrates the ability of the arrester to withstand the declared values for bending loads. Specified long-term load (SLL) and Specified short-term load (SSL) are declared for all Station arresters.

PROCEDURE The preparation shall be performed on three samples

Initial verifications - measurement of the power losses at Uc and at ambient temperature - internal partial discharge at a test voltage 1,05 times the continuous operating voltage (not performed) - measurements of the residual voltage test at (0,01 to 1) times the nominal discharge current - leakage test (not performed)

Test procedure a) All three samples were subjected to 1000 cycles of bending moment, each cycle comprising loading from zero to SLL of 5300Nm in one direction, followed by loading to SLL in the opposite direction, then returning to zero load. The cyclic motion shall be approximately sinusoidal form at 0,1 Hz. b) Two of the samples from procedure a) were subjected to a bending moment test. The bending load was increased smoothly to SSL of 6650Nm over 60 s. During this time the deflection was measured. then the load was released smoothly. The maximum deflection was recorded 10 min after the release of the load. The third sample from procedure a) was subjected to a terminal torque. A terminal torque of 47Nm was applied for 30 sec. This sample was then subjected to four 24 hours thermal cycles of heating and cooling as shown in fig. 11 of the reference standard while mechanically stressed at the specified load of 5300Nm. The load direction was changed every 24 hours according to fig. 12 of the reference standard c) Subject all three samples to water immersion test. The samples were kept for 42 hours in a boiled deionized water with 1kg/m3 of NaCl .

Test evaluation Final verifications - measurement of the power losses at a test voltage Uc and at an ambient temperature - internal partial discharge at a test voltage 1,05 times the continuos operating voltage - measurement of the reference voltage at the reference current before residual voltage test - measurements of the residual voltage test at (0,01 to 1) times the nominal discharge current for two successive impulse - measurement of the reference voltage at the reference current after residual voltage test - leakage test

RESULTS The visual inspection of the samples after the test has revealed no visible damage. The variation of the power losses measured before and after the test was less than 20%. The variation of the residual voltage measured at (0,01 to 1) times the nominal discharge current before and after the test was less than 5%. The difference in voltage between two successive impulses was less than 2% and the relevant oscillogram reveals no sign of breakdown. The variation of the reference voltage before and after the two residual voltage test was less than 2%. The partial discharges measured before and after the test were less the specified limit of 10 pC. All acceptance criteria are satisfied, therefore the test result is positive.

CT235009EN Page: 14 of 19 TEST J WEATHER AGEING TEST

Report Number H18074 Certifying Laboratory FGH

OBJECTIVE The purpose of this test is to demonstrate the ability of the VariSTAR Type U3AF Station-Class Surge Arresters to withstand electrical stresses on the arrester housing caused by exposure to salt fog, in accordance with this standard.

PROCEDURE Complete 144 kV rated sample was used for this test. The Reference Voltage at specified Reference Current and Partial Discharge at 1.05 x MCOV were recorded. Samples were mounted vertically in a moisture-sealed corrosion-proof chamber. The fog should continually fill the chamber. The samples were energized at MCOV for time duration of 1,000 hours. The samples were inspected after testing to assure no physical damage occurred. The Reference Voltage at specified Reference Current and Partial Discharge at 1.05 x MCOV were recorded.

RESULTS VariSTAR Type U3AF Station-Class Surge Arresters met the Accelerated Aging by Exposure to Salt Fog requirements of no tracking occurring, erosion did not penetrate through housing material, sheds and housing were not punctured, reference voltage did not decrease by more than 5% from initial measurements, and partial discharge did not exceed 10 pC before and after testing.

CT235009EN Page: 15 of 19 Table 2:

Creepage Distances and Insulation Withstand Voltages of U3AF High-Strength Station-Class Surge Arresters

Arrester Arrester Creepage Strike 60Hz, dry 60Hz, wet Rating Ur COV Uc Distance Distance 1.2/50 Impulse 60 seconds 60 seconds Grading (kV, rms) (kV rms) Catalog Number (mm) (mm) (kV, crest) (kV, rms) (kV, rms) Ring 3 2.55 U3AF003002A1445AAA 1719 390 221 136 124 No 6 5.1 U3AF006005A1445AAA 1719 390 221 136 124 No 9 7.65 U3AF009007A1445AAA 1719 390 221 136 124 No 10 8.4 U3AF010008A1445AAA 1719 390 221 136 124 No 12 10.2 U3AF012010A1445AAA 1719 390 221 136 124 No 15 12.7 U3AF015012A1445AAA 1719 390 221 136 124 No 18 15.3 U3AF018015A1445AAA 1719 390 221 136 124 No 21 17 U3AF021017A1445AAA 1719 390 221 136 124 No 24 19.5 U3AF024019A1445AAA 1719 390 221 136 124 No 27 22 U3AF027022A1445AAA 1719 390 221 136 124 No 30 24.4 U3AF030024A1445AAA 1719 390 221 136 124 No 33 27.5 U3AF033027A1445AAA 1719 390 221 136 124 No 36 29 U3AF036029A1445AAA 1719 390 221 136 124 No 39 31.5 U3AF039031A1445AAA 1719 390 221 136 124 No 48 39 U3AF048039A2445AAA 2901 603 342 205 172 No 54 42 U3AF054042A2445AAA 2901 603 342 205 172 No 60 48 U3AF060048A2445AAA 2901 603 342 205 172 No 66 53 U3AF066053A2445AAA 2901 603 342 205 172 No 72 57 U3AF072057A2445AAA 2901 603 342 205 172 No 78 62 U3AF078062A3645AAA 4319 858 488 290 230 No 84 68 U3AF084068A3645AAA 4319 858 488 290 230 No 90 72 U3AF090072A3645AAA 4319 858 488 290 230 No 96 76 U3AF096076A3645AAA 4319 858 488 290 230 No 108 88 U3AF108088A4845AAA 5738 1113 635 375 288 No 108 84 U3AF108084A4845AAA 5738 1113 635 375 288 No 120 98 U3AF120098A4845AAA 5738 1113 635 375 288 No 132 106 U3AF132106A4845AAA 5738 995 617 344 317 Yes 138 111 U3AF138111A4845AAA 5738 995 617 344 317 Yes 144 115 U3AF144115A4845AAA 5738 995 617 344 317 Yes 162 130 U3AF162130A6045AAA 7220 1354 833 481 414 Yes 168 131 U3AF168131A6045AAA 7220 1354 833 481 414 Yes 172 140 U3AF172140A7245AAA 8638 1609 979 566 472 Yes 180 144 U3AF180144A7245AAA 8638 1609 979 566 472 Yes 192 152 U3AF192152A7245AAA 8638 1609 979 566 472 Yes 198 160 U3AF198160A8445AAA 10057 1853 1105 634 547 Yes 204 165 U3AF204165A8445AAA 10057 1853 1105 634 547 Yes 216 174 U3AF216174A8445AAA 10057 1853 1105 634 547 Yes 228 180 U3AF228180A8445AAA 10057 1853 1105 634 547 Yes 240 190 U3AF240190A9645AAA 11476 1996 1148 679 528 Yes 258 209 U3AF258209A9645AAA 11476 1996 1148 679 528 Yes 264 212 U3AF264212A9645AAA 11476 1996 1148 679 528 Yes 276 220 U3AF276220A9645AAA 11476 1996 1148 679 528 Yes 288 230 U3AF288230A9645AAA 11476 1996 1148 679 528 Yes

* Creepage distances are based on standard arrester build configurations.

CT235009EN Page: 16 of 19 Table 3: Protective Characteristics of the UltraSIL Polymer-Housed U3AF Arrester Arrester Arrester FOW Maximum Residual Voltage (kV Switching Surge Protective Rating Ur COV Uc TOV TOV (kV crest) 8/20 µs Current Wave Level (kV crest) (kV, rms) (kV rms) 1 sec 10 Sec Crest) 1.5k 3kA 5kA 10kA 20kA 40kA 125A 250A 500A 1000A 3 2.55 3.3 3.1 8.1 6.5 6.8 7.1 7.8 8.4 9.4 5.7 5.8 6 6.3 6 5.1 6.6 6.2 16.3 13 13.7 14.3 15.5 16.8 18.7 11.4 11.7 12 12.5 9 7.65 9.9 9.4 24.4 19.5 20.5 21.4 23.3 25.2 28.1 17.1 17.5 18.1 18.8 10 8.4 10.9 10.3 26.8 21.4 22.5 23.5 25.5 27.7 30.9 18.7 19.2 19.8 20.6 12 10.2 13.2 12.5 32.6 26 27.3 28.6 31 33.6 37.5 22.8 23.3 24.1 25 15 12.7 16.4 15.5 40.6 32.3 34.1 35.6 38.6 41.8 46.7 28.3 29.1 30 31.2 18 15.3 19.8 18.7 48.9 38.9 41 42.9 46.5 50.4 56.2 34.1 35 36.1 37.5 21 17 22 20.8 54.3 43.3 45.6 47.6 51.7 56 62.5 37.9 38.9 40.2 41.7 24 19.5 25.2 23.8 62.3 49.6 52.3 54.7 59.3 64.2 71.7 43.5 44.6 46.1 47.8 27 22 28.4 26.9 70.3 56 59 61.7 66.9 72.4 80.9 49.1 50.4 52 54 30 24.4 31.5 29.8 78 62.1 65.4 68.4 74.2 80.3 89.7 54.4 55.9 57.6 59.9 33 27.5 35.5 33.6 87.9 70 73.7 77.1 83.6 90.5 101 61.4 63 65 67.5 36 29 37.5 35.5 92.7 73.8 77.8 81.3 88.2 95.5 107 64.7 66.4 68.5 71.1 39 31.5 40.7 38.5 101 80.2 84.5 88.3 95.8 104 116 70.3 72.1 74.4 77.3 48 39 50.4 47.7 125 99.2 105 109 119 128 143 87 89.3 92.1 95.7 54 42 54.3 51.4 134 107 113 118 128 138 154 93.7 96.1 99.2 103 60 48 62 58.7 153 122 129 135 146 158 176 107 110 113 118 66 53 68.5 64.8 169 135 142 149 161 174 195 118 121 125 130 72 57 73.6 69.7 182 145 153 160 173 188 209 127 130 135 140 78 62 80.1 75.8 198 158 166 174 188 204 228 138 142 146 152 84 68 87.9 83.2 217 173 182 191 207 224 250 152 156 161 167 90 72 93 88.1 230 183 193 202 219 237 265 161 165 170 177 96 76 98.2 92.9 243 193 204 213 231 250 279 170 174 180 186 108 88 114 107.6 281 224 236 247 268 290 323 196 201 208 216 108 84 109 102.7 268 214 225 235 255 277 309 187 192 198 206 120 98 127 119.9 313 249 263 275 298 323 360 219 224 231 240 132 106 137 129.6 339 270 284 297 322 349 390 237 243 250 260 138 111 143 135.8 355 282 298 311 337 365 408 248 254 262 272 144 115 149 140.6 367 293 308 322 350 379 423 257 263 272 282 162 130 168 159 415 331 349 364 395 428 478 290 298 307 319 168 131 169 160.2 419 333 351 367 398 431 481 292 300 309 321 172 140 181 171.2 447 356 375 392 426 461 515 312 320 331 343 180 144 186 176.1 460 366 386 404 438 474 529 321 330 340 353 192 152 196 185.9 486 387 408 426 462 500 559 339 348 359 373 198 160 207 195.7 511 407 429 448 486 527 588 357 366 378 393 204 165 213 201.8 527 420 442 462 502 543 606 368 378 390 405 216 174 225 212.8 556 443 467 488 529 573 640 388 398 411 427 228 180 233 220.1 575 458 483 505 547 593 662 402 412 425 442 240 190 246 232.4 607 483 509 533 578 626 698 424 435 449 466 258 209 270 255.6 668 532 560 586 635 688 768 466 478 494 513 264 212 274 259.3 677 539 568 594 644 698 779 473 485 501 520 276 220 284 269.1 703 560 590 617 669 724 809 491 504 520 540 288 230 297 281.3 735 585 617 645 699 757 845 513 526 543 564 * Temporary Overvoltage (TOV) with Prior Duty. ** Based on a 10 kA current impulse that results in a discharge voltage cresting in 0.5 µs. *** 45-60 µs rise time for a 500 A peak current surge.

CT235009EN Page: 17 of 19 Figure 1 – Temporary Over Voltage (TOV) Curves – VariSTAR U3AF

CT235009EN Page: 18 of 19

This page intentionally left blank

CT235009EN Page: 19 of 19 REVISION TABLE REVISION DATE WHAT WAS ADDED/CHANGED NO. 0 04/2020 New Report

Eaton 1000 Eaton Boulevard Cleveland, OH 44122 United States Eaton.com

Eaton’s Power Systems Division 2300 Badger Drive Waukesha, WI 53188 United States Eaton.com/cooperpowerseries

© 2020 Eaton Eaton is a are registered All Rights Reserved trademarks of Eaton. Publication No. CT132009EN All other trademarks are property April 2020 of their respective owners.