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42

DELTA 4000 

ZM-AH02E

 

References

[1]

ANSI Standard 62-1995: “IEEE Guide for Diagnos

-

tic Field testing of Electric Power Apparatus - Part 

1: Oil Filled Power Transformers, Regulators, and 

Reactors”, IEEE New York, 1995

[2]

US Bureau of  Reclamation: “Transformer Diagnos

-

tics”, Facility instructions, standards and techniques 

- Vol. 3-31, 2003

[3]

US Bureau of  Reclamation: “Testing and Mainte

-

nance of  High Voltage Bushings”, Facility instruc-

tions, standards and techniques - Vol. 3-2, 1991

[4]

Schurman, D.: Testing and maintenance of high 

voltage bushings, Western Area Power administra-

tion, 1999

Содержание DELTA 4000

Страница 1: ...WWW MEGGER COM Reference Manual Applications Guide DELTA4000 12 kV Insulation Diagnostic System ZM AH02E Advanced Test Equipment Rentals www atecorp com 800 404 ATEC 2832 Established 1981...

Страница 2: ......

Страница 3: ...f this document However the information contained in this manual is subject to change without notice and does not represent a commitment on the part of Megger Sweden AB Any attached hardware schematic...

Страница 4: ...nsformer excitation current tests 19 Shunt reactors 21 Potential transformers 21 Current transformers 21 Voltage regulators 21 Dry type transformers 22 Bushings 22 Introduction 22 Definitions 22 Bushi...

Страница 5: ...ZM AH02E DELTA4000 5...

Страница 6: ...HV terminal and the current is measured at the LV terminal Voltage and current are accurately measured in amplitude and phase and CHL capacitance dissipation factor power loss etc are calculated and d...

Страница 7: ...phase angle q q 90 It is more convenient to use the dielectric loss angle d where d 90 q For low power factor insulation Ic and I are substantially of the same mag nitude since the loss component Ir...

Страница 8: ...internal measure ment connections UST Ungrounded specimen testing Test mode Measure Ground Guard UST R Red Blue UST B Blue Red UST RB Red and Blue GST Grounded specimen testing Test mode Measure Grou...

Страница 9: ...ZM AH02E DELTA4000 9 1 Introduction...

Страница 10: ...lar types of insulation used Changes in the normal capacitance of an insulation material indicate such abnormal conditions as the presence of a moisture layer short circuits or open circuits in the ca...

Страница 11: ...factor values Typical power factor values 20 C New Old Warning alert limit Power trans formers oil insulated 0 2 0 4 0 3 0 5 0 5 Bushings 0 2 0 3 0 3 0 5 0 5 IEEE 62 1995 states The power factors reco...

Страница 12: ...ielectric loss which in turn causes a further rise in temperature etc thermal runaway It is important to determine the dissipation factor tempera ture characteristics of the insulation under test Othe...

Страница 13: ...may be contaminated enough to cause a signifi cant error Surfaces of potheads bushings and insulators should be clean and dry when making a measurement It should be noted that a straight line plot of...

Страница 14: ...to the test specimen Other sources for interference may be corona discharges espe cially at high humidity and is some cases DC fluctuations in the grounding system Trouble from magnetic fields encoun...

Страница 15: ...ZM AH02E DELTA4000 15 2 Interpretation of measurements...

Страница 16: ...its from each other and it can increase or decrease the apparent value of a capacitor an inductor or a resistor Furthermore the transformer enables us to transmit electrical energy over great distance...

Страница 17: ...applying any voltage on the transformer make sure that all bushing current transformers are shorted out 4 Never perform electrical tests of any kind on a unit under vacuum Flashovers can occur at volt...

Страница 18: ...additional tests of the tertiary winding In some cases transformers are constructed so that the inter windings are shielded by a grounded electrostatic shield or a concentric winding arrangement This...

Страница 19: ...e Subscripts are test num bers H High voltage winding L Low voltage winding T Tertiary winding G Ground Autotransformers In the design of an autotransformer the secondary winding is actually part of t...

Страница 20: ...nd on wye connected transformers Also note that in many cases the maximum applied voltage is limited by the maximum current output Test voltage must always be the same as prior tests if any comparison...

Страница 21: ...tial transformer is securely grounded to a system ground before testing begins this also includes testing of spare transformers Test procedure Ensure the test set is securely grounded 1 Record all tes...

Страница 22: ...handle high electrical stress they could be subjected to mechanical stresses affiliated with connectors and bus support as well Although a bushing may be thought of as somewhat of a simple device its...

Страница 23: ...e the space between the core and the insulating envelope being filled with oil Resin bonded paper insulated bushing A bushing in which the internal insulation consists of a core wound from resin coate...

Страница 24: ...ual inspection Power factor Tan delta test Hot collar test Dete rioration of cemented joints Moisture enters Oil and or gas leaks Filler leaks out Visual inspection Power factor Tan delta test Hot col...

Страница 25: ...e plate voltage rating of the bushing under test If 10kV exceeds the rating of the bushing test at or slightly below the voltage rating 3 Proceed with the test and record the results 4 Identify each s...

Страница 26: ...5kV to prevent inadvertent damage to the insulation An excessive voltage may puncture the insulation and render the tap useless Some bushings do not have a power factor or capacitance tap or an isola...

Страница 27: ...y and Surface Leakage if tests are made under unfavorable weather conditions Test connections GST Connect a ground wire between the test set and the host apparatus for the bushing under test 1 Install...

Страница 28: ...rminal in that phase should be guarded It is also desirable to test samples of the liquid insulation Oil circuit breakers Oil circuit breakers are composed of a steel tank filled with insulating oil A...

Страница 29: ...uld be recorded on the test form Enter all the nameplate information of the oil circuit breaker Identify each set of readings with the bushing se rial number Record manufacturer type or model and othe...

Страница 30: ...loss indexes without the unit being defec tive or deteriorated The losses in an oil circuit breaker are different between an open circuit test and a closed circuit test because the voltage stress on t...

Страница 31: ...rounded Test procedure Tests are performed at 10kV or a voltage suitable for the insulation rating 1 All tests are conducted with the breaker in the open position 2 Identify each set of readings with...

Страница 32: ...s High capacitance s compared to similar tests may be the result of short circuited sections in one or more of the grading capacitors Vacuum circuit breakers These circuit breakers operate on a differ...

Страница 33: ...voltage or slightly above rated voltage The tip up value is obtained by subtracting the value of the dissipation factor measured at the lower test voltage from that measured at the higher test voltage...

Страница 34: ...t at the winding surface Avoid prolonged exposure to high humidity conditions before testing because such exposure may result in moisture absorption in the insulating materials It is desirable to make...

Страница 35: ...s such as thyrite autovalve etc This material has a resistance that decreases dramatically with increasing volt age Arresters are effectively switching devices that serve as an insulator under normal...

Страница 36: ...dependent non linear may be built into an arrester Except for the specific purpose of investigation surface leak age the exposed insulation surface of an arrester should be clean and dry to prevent le...

Страница 37: ...ate contact is made with the critical areas of the insulation Pe troleum jelly or Dow Corning 4 insulating grease applied at the interface surface often helps to obtain better physical contact It may...

Страница 38: ...imen Test The capacitance value from this test is C1 Figure 14 TTR Capacitor measurement The second step of the procedure is to connect the test set and the HV TTR Capacitor to the transformer winding...

Страница 39: ...ZM AH02E DELTA4000 39 3 Testing power system components that no temperature change has occurred and the trans former ratio determined by this method is correct...

Страница 40: ...nce 14 H High Voltage turns ratio measurements 38 Hot collar test 27 Humidity 13 I IEEE 62 1995 power factor values 11 Insulating envelope 23 Internal insulation 23 Interpretation of measurements 10 I...

Страница 41: ...nnections 36 Surge lightning arresters 35 T Temperature 12 Testing power system components 16 Three winding transformers 18 Transformer excitation current tests 19 Transformers 16 Two winding transfor...

Страница 42: ...eactors IEEE New York 1995 2 US Bureau of Reclamation Transformer Diagnos tics Facility instructions standards and techniques Vol 3 31 2003 3 US Bureau of Reclamation Testing and Mainte nance of High...

Страница 43: ...ZM AH02E DELTA4000 43...

Страница 44: ...TYPES S SI SM TYPE U 0 32 0 1 09 0 93 1 00 1 18 1 26 1 02 1 33 8 1 09 0 94 1 00 1 17 1 25 1 02 2 35 6 1 09 0 95 1 00 1 16 1 24 1 02 3 37 4 1 09 0 96 1 00 1 15 1 22 1 02 4 39 2 1 09 0 97 1 00 1 15 1 2...

Страница 45: ...59 0 1 00 0 95 1 12 1 03 16 60 8 1 00 17 62 6 1 00 18 64 4 1 00 19 66 2 1 00 20 68 0 1 00 1 00 1 00 1 00 21 69 8 1 00 22 71 6 1 00 23 73 4 1 00 24 75 2 1 00 25 77 0 1 00 1 04 0 89 0 97 26 78 8 1 00 2...

Страница 46: ...46 DELTA4000 ZM AH02E...

Страница 47: ...ZM AH02E DELTA4000 47...

Страница 48: ...d Dover CT17 9EN England T 44 0 1304 502101 F 44 0 1304 207342 E UKsales megger com Other Technical Sales Offices Dallas USA Toronto CANADA Trappes FRANCE Oberursel GERMANY Oberkulm SWITZERLAND Johann...

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