Biddle BM25_UG 电路图.pdf

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1、5kV Digital Insulation Tester MEGGER BM25 User Guide Guide de lutilisateur Gebrauchsanleitung MeterCenter Gua del usuario Telephone: +1 480-659-8351 Toll Free in U.S. 800-230-6008 MEGGER BM25 - July 98 22/6/00 10:31 am Page 1 RadioFans.CN 收音机爱 好者资料库 Application Notes Preventive Maintenance17 Insulat

2、ion Testing Concepts18 Application of Test Techniques Short time or Spot Test19 Polarization Index (PI) Test19 Dielectric Discharge (DD) Test20 Stress considerations21 Specification 22 Accessories25 Appendix 1 - Results displayed at the end of each test26 Appendix 2 - RS 232 Output information displ

3、ay examples28 Repair and Warranty29 Symbols used on the instrument Caution: Refer to accompanying notes. Risk of electric shock. Equipment complies with relevant EU Directives Equipment protected throughout by Double Insulation (Class II). ContentsGuide de lutilisateur - p30Gebrauchsanleitung - s50G

4、ua del usuario - p70 2 Safety Warnings 3 General Description 4 Test Mode Summary5 Features and Controls6 Battery Charging7 Operation Testing Precautions8 Performing Tests - General9 Testing procedures10 Insulation Resistance Testing (R)10 Test Current measurement (I)10 Polarization Index Testing (PI

5、)10 Dielectric Discharge Testing (DD)11 Step Voltage Testing (SV)11 Factory settings12 Custom timed PI test12 Custom timed DD test12 Setting Custom Test Time values12 Using the Guard Terminal13 Measurements above 100 G 13 Fault Conditioning (BURN)14 Condition and Warning Indicators15 Data Download16

6、 BM25 - July 98 22/6/00 10:31 am Page 2 RadioFans.CN 收音机爱 好者资料库 3 SAFETY WARNINGS Safety Warnings and Testing Precautions must be read and understood before the instrument is used. They must be observed during use The circuit under test must be switched off, de-energised and isolated before test con

7、nections are made. The BM25 can generate up to 2 mA at 5000 V. Circuit connections must not be touched when HV is selected. Circuits must be discharged before disconnecting the test leads. In certain circumstances, break-down of the circuit under test could cause the instrument to terminate the test

8、, possibly causing a loss of display while the circuit remains energised. In this event, it is important that the circuit is allowed to discharge and the instrument is turned off before touching any connections. The test terminal area and charging panel recess should be kept in a dry, clean conditio

9、n. Replacement fuses must be of the correct type and rating. The instrument should not be used if any part of it is damaged. Refer to Testing Precautions on page 8 for further explanations and precautions. NOTE THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS. BM25 - July 9

10、8 22/6/00 10:31 am Page 3 RadioFans.CN 收音机爱 好者资料库 Battery capacity is continuously displayed by a segmented indicator. The indicator flashes when the battery requires recharging. Power is obtained from two parallel connected sealed rechargeable lead acid batteries. If either battery fails (or an int

11、ernal protection fuse ruptures) the instrument will continue to operate on the alternative battery. The battery is recharged by external 95 - 265V a.c., 50-60 Hz, or 12 V d.c.supply. Charging connections, mains power indicator and instrument protection fuses are located in a splashproof protected re

12、cess in the front panel. Specially designed lid hinges enable the lid to be removed and replaced as required, and will protect the lid from strain or damage by unclipping itself if unintentionally opened past its full extent. Design safety features include:- The flashing HV warning LED on the front

13、of the instrument , and the flashing H.V. symbols on the display remind the user that hazardous voltage is present when testing. External voltage 50 V displayed with flashing H.V. symbols on the display. Load automatically discharged at the end of a test, and decaying voltage ( 50 V) displayed. Inte

14、rlocked sliding cover to prevent simultaneous access of charging and test terminals. Test terminal sockets lock test leads into the case and prevent accidental disconnection. General Description 4 The BM25 is a compact, automated high voltage, battery powered instrument used to carry out Polarizatio

15、n Index, Step Voltage, and Dielectric Discharge tests as well as spot Insulation tests. The BM25 has a resistance measurement capability up to 5 T and leakage current measurement enables resistances up to 500 T to be measured. The design of the instrument takes full advantage of microprocessor techn

16、ology and features a large, clear liquid crystal display, combining digital and analogue readings of insulation resistance. Set nominal voltage options of 500 V, 1000 V, 2500 V and 5000 V are selectable. A variable output voltage setting provides a range of 25 V to 5000 V incremental in 25 V steps.

17、At switch on, the instrument carries out a calibration self check which automatically adjusts the measurement system. The calibration sequence inhibits any testing if the measurement system fails to meet preset limits. On starting a test, the HV warning LED on the front of the instrument flashes, to

18、gether with the display HV warning symbols. The integral timer starts automatically and displays minutes and seconds elapsed since the start of the test. The timer can be used to set the duration of a test, and will automatically stop the output voltage when the set time has expired. During a test,

19、measurements are automatically sent every 5 seconds via an isolated optical link to the RS 232 connector to enable downloading of the results to a computer. BM25 - July 98 22/6/00 10:31 am Page 4 final resistance value, and capacitance value. Custom timed DD values can be set if required (see Custom

20、 timed DD test). Step Voltage Testing (SV) This 5 minute test depends on the principle that an ideal insulator will produce identical resistance readings at all voltages. Conversely, an insulator which is being over stressed will show lower values at higher voltages. Operating at either 2,5 kV or 5

21、kV, the voltage steps up one fifth every minute, and successive measurements are taken. On completion, each of the 5 separate results are sequentially displayed followed by the capacitance value. Fault Conditioning (Burn) This low current feature is used to carry out continuous testing under breakdo

22、wn conditions. General Notes: 1) Acapacitance value reading is only available if the test has run for more than one minute, and the reading was not over-range. 2) Internal discharge resistors are automatically selected :- -At the end of a test. -If the instrument is switched off. -If an internal err

23、or is detected. Any voltage remaining on the terminals at the end of a test,will be displayed until it has decayed to less than 50 V. During a test output terminal voltage is displayed, together with flashing high voltage symbols, and the flashing red LED. Test Mode Summary 5 Insulation Resistance T

24、esting (R) This mode measures insulation resistance at the selected voltage to provide an instantaneous spot reading. Final test result is given sequentially with the corresponding leakage current and capacitance value. Test Current measurement (I) This mode measures insulation at the selected volta

25、ge to provide an instantaneous spot reading, but displays leakage current value on the digital display. (N.B. The analogue scale always displays resistance). Final test result is given sequentially with the corresponding resistance and capacitance value. Polarization Index Testing (PI) Polarization

26、Index is the term applied to the Dielectric Absorption ratio, when the insulator is subjected to an insulation resistance test, and the resistance values are measured after time T1 (Default 1 minute) and again after time T2 (Default 10 minutes). Polarization Index is calculated automatically from th

27、e resistance value after time T2, divided by the resistance value after time T1. High dielectric absorption is indicated by high PI ratio (see Application of test Techniques). Final test results are given sequentially with the corresponding leakage current and capacitance value. The test will run at

28、 any voltage. Custom timed PI values can be set if required (see Custom timed PI test on page 12). Dielectric Discharge Testing (DD) This mode measures the dielectric absorption of an item under test while ignoring the effects of parallel surface leakage paths. Default test time is 30 minutes follow

29、ed by 1 minute discharge. Final test results are given sequentially with a PI value, the BM25 - July 98 22/6/00 10:31 am Page 5 6 Features and Controls IL ML M 2500V 1000V 500V BREAK? DOWN 5000V EXT? VOLTS NOISE LAST? TEST SV PI DD BURN I R MEGGER BM25 FS2 ? +G 1T Terminal Connection covers Individu

30、ally lifted to access test lead terminals. Covers interlocked with sliding recess cover. Splashproof recess Cover Slides back to reveal mains and 12V battery charging connections together with instrument protection fuses. Voltage display Test voltage or external voltage 50V, together with flashing H

31、.V. symbols. Condition and Warning indicators Flash to indicate any adverse conditions affecting the test. Also indicates when results of last test are being sequentially displayed. RS232C socket Sends test results every 5 secs to enable download to PC. Display right hand cursor Indicates selected T

32、est mode. Display left hand cursor Indicates selected voltage, or the timer. Battery capacity Indicator Segments recede as battery is used. Symbol flashes when battery charge is excessively low. Test Push Press for at least 1 second to initiate test and start Timer. Press again to manually stop test

33、. Range Keys 1) Select test mode. 2) Adjust variable voltage. 3) Set timer. Max. 90 minutes. Selector Keys 1) Set voltage 2) Set Timer On/Off Button Press to turn On /Off. (Wait a few seconds for Automatic Calibration) Timer display - Shows set test duration and displays time elapsing during test. H

34、V Warning - Flashes when a test is in progress, or a BM25 - July 98 22/6/00 10:31 am Page 6 General It is advisable to fully charge the battery before the instrument is put into service for the first time. Charging is carried out by external a.c. mains supply, or by 12 V d.c. supply. A 12 V charging

35、 lead fitted with an automotive cigar lighter plug is available for charging the battery from a vehicle.Testing is inhibited during charging. Mains supply re- charging Mains input recharging requires a voltage within the range 95 - 265 V a.c., 50 - 60 Hz. Disconnect the test leads and connect the ma

36、ins supply to the IEC 320 connector in the charging recess. Confirm that the red indicator lamp is illuminated. Charging is automatic as soon as the mains supply is connected. To fully recharge the battery takes about 16 hours. Eight hours charging (from a fully discharged state) will achieve at lea

37、st 90% of full charge. Turn the instrument on and check the battery capacity indicator to show the state of charge. 12 V d.c. supply re- charging This method of re-charging should only be carried out if a mains supply is unavailable as it is slower and less efficient. If using a vehicle as the charg

38、ing source, the engine should be running. Observing correct polarities shown, connect the 12 V DIN socket to the external 12 V d.c. supply and switch on. Caution: Applying more than 15 V to this socket will overcharge the battery. 12 V DIN socket (Viewed from front of panel) Battery Charging Notes 1

39、)Do not leave battery in a totally discharged state. Frequent charging to keep the battery topped up will maximise battery life. 2)Battery charging should be carried out in a dry environment (the IP54 environmental protection applies with the charging cover securely closed). 3)When charging the batt

40、ery indoors, the area should be well ventilated. 4)The battery should only be charged at temperatures in the range 0 C to 40 C. 5)It is beneficial to continue charging and no harm will occur to the battery if the charger is left on indefinitely. 6)If the instrument is idle for long periods, recharge

41、 the battery for at least 24 hours every 6 months. (More frequently if the storage temperature is 40 C). Battery Charging 7 +G FS1FS2 100mA(T) 250V IEC127/1 95-265V a.c. 50-60Hz 24VA 400mA 100mA 250V IEC127/1 + 10-15 V d.c. Leave unconnected Connect to +ve Connect to - ve FS1 Mains Input Fuse Mains

42、Input 12V d.c. Input FS2 Guard Fuse BM25 - July 98 22/6/00 10:31 am Page 7 9.The BM25 has an environmental protection classification of IP54 with the charging recess cover securely closed. It is important from a safety point of view (and to avoid unwanted leakage currents) to ensure that the testing

43、 terminal area and the charging recess are kept free from dirt and moisture. 10. Before use, any surface water on the instrument must be removed, especially from the test lead sockets 11. Fuse replacements must be of the correct type and rating. Refer to the Specification section for correct replace

44、ment fuse details. 12. If any part of the instrument is damaged, it should not be used, but returned to the manufacturer or an approved repair company. 13. Should the plug on the power cord not be the type for your socket outlets (receptacles), do not use an adaptor. Use a suitable alternative mains

45、 cord. Wires in power cords are coloured as follows: U.K/InternationalU.S.A. Earth (Ground)Yellow/GreenGreen Neutral BlueWhite Phase (Line)Brown Black Operation 8 Testing Precautions 1.The instrument must only be used by suitably trained and competent persons. 2.Circuit connections must not be touch

46、ed during a test. 3. The BM25 can give an electric shock. Highly capacitive circuits (e.g. long lengths of cable) charged to several kV can create a potentially lethal charge. 4.Care must be taken to prevent capacitive circuits becoming disconnected during a test, leaving the circuit in a charged st

47、ate. 5.The voltmeter and automatic discharge feature of the BM25 should be regarded as additional safety features and not a substitute for normal safe working practice. 6. When carrying out prolonged tests unattended, care should be taken that no harm or damage can be caused. 7.When using the BURN f

48、eature, care should be taken that no harm or significant damage can be caused. 8.In certain circumstances, break-down of the circuit under test may conceivably cause the instrument to terminate the test, possibly causing a loss of display while the circuit remains energised. In this event, the circu

49、it must be discharged and the instrument turned off before touching any connections. The circuit under test must be completely de-energized and isolated before test connections are made. BM25 - July 98 22/6/00 10:31 am Page 8 6.Start a test by pressing the red test button for at least 1 second. The flashing red LED and the flashing H.V. symbols warn that a test is in progress. 7.When testing resistive or moderately capacitive loads (up to about 1F) the test voltage will appear within a few seconds. The test voltage is controlled