EDS3365 Manual in PDF format - Bender

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3 Op erating principle of the EDS3365Operating principleinsulation fault location(EDS-mode)AttentionWhen a first insulation fault occurs in IT systems, a fault current flows which isessentially determined by the system leakage capacitances. The basic concept infault location is therefore to close the fault current circuit for a short period over adefined resistance. As a result of this principle, the system voltage itself drives a testcurrent which includes a signal that can be evaluated.The test current is generated periodically by the PGH183 (which is a component ofthe EDS3365 system). The test current is limited in amplitude and time. As thishappens, the system conductors are connected alternately to earth over a definedresistance. The fault current which is generated in this manner depends on the sizeof the present insulation fault, and on the system voltage. It is limited to a maximumof 2.5 mA, and when I max= 1 mA is set, it is limited to 1 mA. For planning purposes,it should be noted that no system components are present in which this test currentcan bring about a damaging reaction, even in unfavourable cases.Voltage sourceL1(L+)IT systemConsumerL2(L-)Current clamp orcurrent transformerPGH183orPGH473test device132EDS165-3evaluatorInsulation faultRFPEThe test current pulse flows from the test device via the live conductors, taking theshortest path to the location of the insulation fault. From there, it flows via theinsulation fault and the earth conductor (PE conductor) back to the test device. Thiscurrent pulse ist then detected by the current clamps or measuring currenttransformers located in the insulation fault path, and is reported by the connectedEDS165-3 evaluator.The current clamps and/or measuring current transformers are used as residualcurrent transformers – that is to say, the PE conductor is not passed through thetransformer.Important: normal commercial current clamps or measuring current transformersmust not be used.PositionPGH4731 3 2 3 12 sec 4 sec 2 sec 4 secThe test cycle of PGH183 in differentswitch positions (1, 2, 3) is shown in thediagram on the left.EDS start10TGH1320E/03.2000
Operating principle of the EDS3365Response valuesThe response value is determined by the sensitivity of the EDS165-3 evaluator. InDC as well as AC systems, this is 0.5 mA as an arithmetic mean value .The accuracy is +/- 0.2 mA of the displayed measurement value. Systeminterferences and excessively high system leakage capacitances may have a negativeinfluence on the accuracy.TerminologyIn this operating manual, certain measurement engineering terms will occurrepeatedly. The most important of these terms are demonstrated and explained withthe help of the following sketch.Voltage sourceIT systemMeasuring current transformeror current clampConsumerI ∆EDS473-12EDS165-3PGH473PGH183C E-VR F-VCE-NR F-NPEI ∆Residual current through the measuring current transformer:I ∆max1 A = FAULTC E-VUpstream capacitances, system leakage capacitances upstreamthe measuring current transformerC E-NDownstream capacitances, system leakage capacitancesdownstream the measuring transformerR F-VInsulation fault upstream the measuring current transformerR F-NInsulation fault downstream the measuring current transformerPGH183, PGH473 Insulation fault test deviceEDS165-3, EDS473-12 Insulation fault evaluatorsEarth fault loop of the test current I pr(I pr min= 0.5 mA, I pr max= 2.5/1 mA)Residual currents I ∆The insulation fault location system EDS3365 detects insulation faults downstreamof the measuring current transformer (R F-N), subject to the condition that the testcurrent is more than 0.5 mA.The total residual current through the measuring current transformer consists ofthe test current and the residual currents which result from the capacitances C E-V,C E-N, and/or insulation faults R F-N. The total residual current through the measuringcurrent transformer may be a maximum of 1 A. If higher residual currents occur,a FAULT message to this effect is given, and no evaluation is possible on thischannel. On this point, please refer to the FAULT curve on the next page as well.The upstream capacitances C E-Vmust be at least as large as the downstreamcapacitances C E-N(C E-V≥ C ). If this condition is not satisfied, false tripping signalsE-Nmay be given.Note: under certain circumstances, balanced insulation faults downstream of themeasuring current transformer are not detected.11TGH1320E/03.2000
Page 4 and 5: 1 About the EDS3365What is EDS3365T
Page 6 and 7: About EDS3365Basic standardsIf a po
Page 8 and 9: Safety instructionsAny faults which
Page 12 and 13: Operating principle of the EDS3365F
Page 14 and 15: ONOperating principle of the EDS336
Page 16 and 17: Product descriptionParts listThe ED
Page 18 and 19: Product descriptionTest device PGH1
Page 20 and 21: Product descriptionTechnical dataED
Page 22 and 23: 5 Op eration and S ettingFactory se
Page 24 and 25: Operation and S ettingThe EDS165-3
Page 26 and 27: Operation and S ettingThe EDS165-3
Page 28 and 29: Operation and S ettingSerial interf
Page 30 and 31: 6 Points to be considered b efore u
Page 32 and 33: Points to be considered before useC
Page 34 and 35: Points to be considered before useA
Page 36 and 37: Practical use• Check the switch p
Page 38 and 39: PRC470ALARM RS485RS485ONSLAVE ADDRE
Page 40 and 41: ONPractical useInsulation fault loc
Page 42 and 43: Practical useSequence of theinsulat

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