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1. Test start stop Line input Present indicator Power on off Q I selector Data record High voltage warning indicator Voltage at Test modes Burn indicator Alarm Data recording Battery E gt d k Co ont Timers Main T1 Srei qom 100M 1G Brea down Analogue indicator display b High GOTO B EE MQkQ voltage Wenig men mAUAnA warning ater T1 DAR 1m Pi2m 1m TC 3m 4m 10m indicator BBB PBRB 2588s BBBRE Dielectric x absorption Digital Polarisation Time Capacitance ratio T1 timer display index timer T2 constant display Power On Off button The instrument will only turn on if this button is pressed held and then released when the display responds The instrument will not turn on if the button is released before the display responds or if the button is held down for too long This is a safety feature to prevent the instrument being inadvertently turned on The instrument is turned off either by timing out after 10 minutes of inactivity or by pressing the button again Upon switching the instrument on the display will first show Ini while it undergoes a self checking routine When Ini disappears the instrument is ready for use Test voltage A and V buttons Using these buttons one of five test voltages can be selected 250 V 500 V 1 kV 2 5 kV and 5 kV The selected voltage is shown on the display A non standard voltage between 50 V and 5 kV can be selected by holding down th
2. Tel 44 0 1304 502 243 Tel 1 610 676 8579 Fax 44 0 1304 207 342 Fax 1 610 676 8625 Megger operate fully traceable calibration and repair facilities ensuring your instrument continues to provide the high standard of performance and workmanship you expect These facilities are complemented by a worldwide network of approved repair and calibration companies to offer excellent in service care for your Megger products 20 Returning your product to Megger UK and USA service centres 1 When an instrument requires recalibration or in the event of a repair being necessary a Returns Authorisation RA number must first be obtained from one of the addresses shown above You will be asked to provide the following information to enable the Service Department to prepare in advance for receipt of your instrument and to provide the best possible service to you m Model e g MIT520 m Serial number to be found on the underside of the case or on the calibration certificate m Reason for return e g calibration required or repair m Details of the fault if the instrument is to be repaired 2 Make a note of the RA number A returns label can be emailed or faxed to you if you wish 3 Pack the instrument carefully to prevent damage in transit 4 Ensure the returns label is attached or that the RA number is clearly marked on the outside of the package and on any correspondence before sending the instrument freight paid
3. and G These terminals are designed to accept only the test leads supplied Shutters across the terminals prevent accidental ingress of dirt and other objects Test lead plugs interlock with the shutters and are released by rotating the test lead plug a quarter turn The Guard terminal is explained below and is only used in cases where surface leakage currents need to be eliminated Most measurements use just the and terminals The instrument s internal voltage generator drives the terminal with respect to the terminal current being measured in the terminal Guard terminal For basic insulation tests and where there is little possibility of surface leakage affecting the measurement it is unnecessary to use the guard terminal i e if the insulator is clean and there are unlikely to be any adverse current paths However in cable testing for example there may be surface leakage paths across the insulation between the bare cable and the external sheathing due to the presence of moisture or dirt Where it is required to 12 remove the effect of this leakage particularly at high testing voltages a bare wire may be bound tightly around the insulation and connected via the third test lead to the guard terminal G To ve Terminal To Guard Terminal The guard terminal is at the same potential as the negative terminal Since the leakage resistance is effectively in parallel with the resistance to be measured the u
4. 1 TQ Short circuit charge current 3mA Capacitor charge time lt 5 seconds per uF at 3mA Capacitor discharge time 120 ms per uF to discharge from 5 kV to 50 V Capacitance measurement 500 V minimum test voltage 10 nF to 50 uF dependent on test voltage Capacitance measurement accuracy 23 C 5 5 nF 18 Voltage output accuracy 0 C to 30 C 4 0 10 V of nominal test voltage at 1 GQ load Current measurement range 0 01 nA to 5 mA Current measurement accuracy 23 C 5 0 2 nA at all voltages Interference rejection 2mA rms at 200 V and above Timer range Counts up to 99 minutes and 59 seconds from start of test Test regimes Auto IR PI SV DD DAR is calculated automatically if timers T1 and T2 are set Interface RS232 38400 Baud 8 data bits 0 parity 1 stop bit no flow control USB Data storage Data stored selected voltage test time elapsed voltage applied leakage current and insulation resistance The PI DAR capacitance time constant and DD values are also stored if available at the end of the test Megger Download Manager may be used to transfer this data to a PC Data output Real time serial data output once per second of the test voltage test current and resistance Lead set Three flexible silicon insulated leads with compact clamp Safety Meets the requirements of EN61010 1 2001 CAT III 300V EMC Meets the requirements of EN61326 1 1998 for use in heavy industrial are
5. between 1000 and 5000 V Fn VW i Voltage range between Decrement in 25 V steps Fn TA or TV Cycle through timers Fn Mode Cycle through IR modes Select breakdown burn or alarm limit for IR test Fn Q Download mode See Downloading results Fn V9 Clear stored data The record button is pressed twice Mode button Press down on the MODE button to cycle through and select the test mode Modes of test to be chosen from include an insulation resistance IR test a polarization index PI test a step voltage SV test and a dielectric discharge DD test The insulation resistance IR test operates in either burn or breakdown mode with an option of setting a resistance threshold alarm limit These modes can be cycled through and selected by holding down the Fn button and pressing the Mode button Timer A and V buttons The main timer can be set up to 99mins 59secs The TA button increments the time and the TW button decrements the time in ten seconds steps An auto repeat facility allows the time to be set more quickly Setting a time of 00 00 disables the timer With the timer disabled a test has to be manually stopped To select timer Tmain T1 or T2 hold down the Fn button whilst repeatedly pressing the TA or TWbuttons To set the selected timer release the Fn button and the use the TA or TWbuttons Note T2 cannot exceed the time on main timer unless it i
6. current decays from a lower value with a relatively long time constant of up to several minutes If this component of the discharge current is large gt 7 500 V test voltage then the insulation condition is poor The main timer will default to 30 minutes which is normally sufficient time for full absorption to take place in an insulation material The default test voltage is set to 500 V The DD test requires the instrument to measure the discharge current 1 minute after the removal of the test voltage At this time the capacitive current should be insignificant compared with the released absorption current On completion of the test the instrument uses this measurement along with the test voltage and calculated capacitance to produce a figure of merit indicating the quality of the insulation Dielectric Discharge DD I min VxC where I is the measured current expressed in milliamps mA V is the test voltage in Volts V and C is the measured capacitance in Farads F 17 SPECIFICATIONS Voltage input range 85 265 V rms 50 60Hz 60 VA Battery life 6 hours continuous testing at 5 kV Test voltages 250 V 500 V 1 kV 2 5 kV 5 kV ranges adjustable in 10 V steps from 50 V to 1 kV and 25 V steps from 1 kV to 5 kV Accuracy 23 C 5 kV 5 0 1 TQ 20 10 TQ Guard 2 error guarding 500 kQ leakage with 100 MQ load Display range Digital display 10 kQ to 15 TQ 3 digits Analogue display 100 kO to
7. internal isolation allows the instrument to be used while the unit is supplied from the mains An internal battery management system switches the instrument off after ten minutes of inactivity If the battery approaches a very low state of charge the instrument turns itself off and mains power must be applied before the instrument can be used again Recorded test results and settings will not be lost when the instrument is switched off A comprehensive LCD display shows resistance current capacitance time constant voltage timer measurements and figure of merit measurements such as polarisation index Features m Continuous resistance or current measurement on main display m Optional resistance current or figure of merit measurements on secondary display m Standard test voltages 250 V 500 V 1 kV 2 5 kV 5 kV m Non standard test voltages selectable between 50 V and 1 kV in 10 V steps and selectable between 1 kV and 5 kV in 25 V steps m Test modes include insulation resistance polarisation index step voltage and dielectric discharge m The dielectric absorption ratio is automatically calculated if the corresponding timers are set m Either burn or breakdown selectable in insulation resistance mode m Insulation Alarm Limit available in insulation resistance mode m Programmable timers include a main test duration timer plus T1 and T2 timers for time resistance method type tests m Load capacitance and t
8. Download Switch the instrument on and wait until initialisation is complete Press the function key along with the record key The instrument now displays dld to indicate download mode Press and hold down test button until download begins shown by analogue display lighting clockwise Results will not be erased during this operation and so may be downloaded repeatedly Deleting test results Switch the instrument on and wait until initialisation is complete Hold down the function key and press the record key twice The instrument now displays clr to indicate clear mode Press and hold down test button until clear process begins shown by analogue display lighting anti clockwise Press the MODE button to exit without deleting the results Recording to a PC While carrying out a test the instrument will output the test voltage test current and resistance every second Refer to section RS232 USB connection for setup details Connect the instrument to the RS232 USB 11 port of the PC The data may be captured with Hyper Terminal or another suitable programme High voltage warning LED This is a red LED next to the TEST button on the front panel The LED flashes when the voltage on the test inputs exceeds 50 V Line input present LED This is a green LED next to the power On Off button on the front panel It is illuminated whenever the mains power is connected Test terminals There are three test terminals marked
9. Megger MIT520 5kV Digital Insulation Tester USER MANUAL Neier WARNINGS Safety Warning must be observed during use m The circuit under test must be switched off de energised isolated and checked to be safe before insulation test connections are made Make sure the circuit is not re energised whilst the instrument is connected m Circuit connections must not be touched during an insulation test m After completing a test capacitive circuits must be completely discharged before disconnecting the test leads Capacitive charges can be lethal m Tested items should be firmly shorted out with a shorting link after discharge until required for use This is to guard against any stored dielectric absorption charge subsequently being released thereby raising the voltage to potentially dangerous levels m The voltage indicator and automatic discharge features should be regarded as additional safety features and not a substitute for normal safe working practice m t is rare but in certain circumstances breakdown of the circuit under test may cause the instrument to terminate the test in an uncontrolled manner possibly causing a loss of display while the circuit remains energised In this event the unit must be turned off and the circuit discharged manually m Test leads including crocodile clips must be in good order clean and with no broken or cracked insulation m The instrument should not be used if any part of it is damaged m Wate
10. R Test settings T1 and T2 times set in order to measure the DAR Test conditions test runs for longer than 10 minutes as this is required for a PI reading F3 wo Ts ABD j Li LI vo 98 99 48 Press Q I E3 cas Press Q I Figure 2 The result of a polarity index test PI Test settings T1 and T2 times set in order to measure the DAR Test conditions timer defaults to 10 minutes as this is required for a PI reading is dih 4 Press Q1 Ti 1 F u mA 10m Press Q I q8 HH oH GU Figure 3 The result of a dielectric discharge test DD Test settings T1 and T2 times set in order to measure the DAR Test condition test runs for longer than 10 minutes as this is required for a PI reading co X As a Da3 Press Q I m7 LL ua BB ABA 5 i eee MN 1m 3 Figure 4 The result of a step voltage SV test Test condition timer defaults to 5 minutes and test voltage defaults to 1000 V C button Pressing this button toggles the display backlight on and off Fn button The function button when pressed allows other keys to perform another function This is summarized in the table below VA and VW represent the 10 test voltage buttons TA and TY represent the timer buttons Button Press Function Comment 1000 and 5000 V Select main timer T1 or T2 Fn VA Voltage range between 50 and 1000 V Fn VW Voltage range between 50 and 1000 V Fn VA Voltage range
11. Readings for contaminated insulation are fairly constant because 16 any absorption effects are masked by high leakage currents On completion of the test the polarisation index is displayed under the segment heading PI Polarisation Index PI Rio min Ry min The Dielectric Absorption Ratio is the term applied to the polarisation index using other time intervals set by T1 and T2 If timers T1 and T2 are both set then the insulation resistance measured at these times is also recorded These are displayed together with the calculated dielectric absorption ratio under the T1 T2 and DAR segments respectively The instrument can be made to display either the insulation resistances insulation currents or ratios plus capacitance measurements by using the X I toggle button See section Q I button for cycling through results and toggling units Dielectric Absorption Ratio DAR Ry min Ry min Dielectric discharge DD test The DD test is a diagnostic insulation test that allows ageing deterioration and voids in the insulation to be assessed The result is dependent on the discharge characteristic so the internal condition of the insulation is tested largely independent of any surface contamination On discharge the capacitive component of the discharge current decays from a high value with a relatively short time constant of a few seconds The other current component comprising the released absorption
12. Testing is disabled if the external voltage exceeds 50 V Testing will stop if the test start stop button is pressed again the preset test time is reached or if the unit is not in burn mode insulation breakdown is detected When a test has finished the instrument will discharge the load which may take some time The operator must always check the load has been discharged before touching the test leads O I button Pressing this button toggles the digital and secondary displays The details available when scrolling the secondary display will depend upon the test mode selected whether timers T1 and T2 have been set and the duration of the test The digital display toggles between insulation resistance and current In the IR PI and DD modes the secondary display initially shows the PI polarity index DAR dielectric absorption ratio and on completion of the test the TC time constant and capacitance measurements Toggling the display shows insulation resistances and currents D i 1 MO PI In the SV step voltage mode the secondary display toggles between DAR TC insulation resistances and currents 1H B p F n Figures 1 to 4 illustrate the display status for sequential Q I key presses in Press Q I the different modes LLLI vo T1 T2 Om gH 93 HB 188 J Press Q I J ULT ua fe AG E Pu EA Figure 1 The result of an insulation resistance test I
13. as Operating temperature 10 C to 50 C Storage temperature 25 C to 65 C Ingress protection lid closed IP65 Humidity 90 RH non condensing at 40 C Dimensions 305 x 194 x 360 mm 12 x 7 6 x 14 2 inches Weight 7 1 kg 16lb approx ACCESSORIES Included accessories 3m lead set User guide on CD ROM Optional accessories 3m lead set with straight jaw clamps 15m lead set Other lead types are available on request Order code 8101 181 6172 960 6220 797 8101 183 19 REPAIR AND WARRANTY The instrument contains static sensitive devices and care must be taken in handling the printed circuit board If an instrument s protection has been impaired it should not be used but sent for repair by suitably trained and qualified personnel The protection is likely to be impaired if for example it shows visible damage fails to perform the intended measurements has been subjected to prolonged storage under unfavourable conditions or has been subjected to severe transport stresses NEW INSTRUMENTS ARE GUARANTEED FOR 1 YEAR FROM THE DATE OF PURCHASE BY THE USER Note Any unauthorized prior repair or adjustment will automatically invalidate the Warranty CALIBRATION REPAIR AND SPARE PARTS For service requirements for Megger Instruments contact Megger Limited or Megger Archcliffe Road Valley Forge Corporate Centre Dover 2621 Van Buren Avenue Kent CT17 9EN Norristown PA 19403 England U S A
14. e Fn function button whilst operating the buttons The selectable voltage is adjustable in 10 V steps between 50 V and 1 kV and adjustable in 25 V steps between 1 kV and 5 kV An auto repeat facility is enabled when the button is held down allowing faster travel through the range If there is an external voltage greater than 50 V on the test leads the high voltage warning indicators are flashed and the display shows this voltage instead The instrument will not perform a test if this voltage is greater than 50 V During a test the display shows the actual voltage on the test leads If the test voltage is changed during a test the new test voltage will be displayed briefly When the test has stopped the display continues to show the voltage present on the test leads Pressing either test voltage A or WV button will then display the test voltage immediately before the end of the test Test start stop button A test will only start if this button is pressed held and then released as soon as the red high voltage warning indicator LED lights The LCD and red LED high voltage warning indicators flash when the test starts A test will not start if the button is released before the red LED shows or pressed continuously for longer than 5 seconds This is a safety feature to prevent a test being started inadvertently The presence of a voltage greater than 50 V on the test leads is indicated with flashing high voltage warning indicators
15. e test will finish automatically after this time has elapsed On test completion insulation capacitance and the time constant associated with it is calculated and displayed Time Constant TC Rins X Cins If timers T1 and T2 are set the instrument will calculate and display the DAR value under the segment DAR On completion of the test the instrument will display the insulation resistance measured at these times under the segment symbols T1 and T2 If the test runs for longer than 10 minutes the instrument will calculate the polarisation index This value will be displayed under the display segment symbol PI On completion of the test the instrument will display the insulation resistance recorded at 1 minute and 10 minutes under the segment symbols 1m and 10m Pressing the Q T button toggles the display to show the insulation resistances insulation currents DAR and PI ratios and capacitance The resistances and currents will be displayed under the TI T2 Im and 10m segment headings the ratios under the DAR and PI segment headings The capacitance reading is indicated by its units of either nF or uF Refer to section Q I button Breakdown mode burn mode The insulation resistance IR test operates in either the Burn or Breakdown mode of operation The default mode is breakdown To change mode press and hold the function button the
16. ime constant measurements displayed at end of test m LCD backlight m Data storage data retrieval and real time data output m USB or RS232 communications m Battery level charge level indicator Cleaning Disconnect the instrument and wipe it with a clean cloth slightly damped with soapy water or Isopropyl alcohol IPA POWER LEAD AND BATTERY CHARGING If the power lead supplied is not suitable for your mains connection do not use an adaptor Always use a power lead fitted with the correct plug The instrument is fitted with a two pin IEC60320 power inlet Most power leads are made with three core cable so the ground connection will not be used Power lead connection table Connection UK International USA Earth Ground Yellow Green Green Neutral Blue White Live Line Brown Black If using a fused plug ensure that it is fitted with a 3 Amp fuse The instrument can be powered from 85 265 Vrms a c at 50 60 Hz The battery will charge as long as the mains supply is connected except when a test is in progress The power On Off button has a green LED which illuminates when mains power is present For optimum battery life charge the battery after each use A completely exhausted battery will take 14 hours to recharge INSTRUMENT CONTROLS AND INDICATORS Line input USB _RS232 Measurement terminals ve guard ve Time A and V selectors Backlight on off Time A and V selectors
17. io M1S 3R2 Canada T 1416 298 9688 Canada only T 1416 298 6770 F 1416 298 0848 E casales megger com
18. ital display The digital display shows the resistance or current being measured during a test The Q I button toggles between the two After a test the display shows the last measurement made until A V or the test start stop buttons are pressed 13 Analogue display This simulates an analogue meter movement to give the user a better feel for how a measurement is progressing The analogue display shows resistance only The display is also used to indicate how result download and delection of results is progressing Secondary display This part of the display shows the results of time resistance method tests 14 T1 DAR 1m T2 PI 2m 1m TC 3m 4m 10m HAE BBB BBBs BBERF Pre Test During test Key action table Key action Fn Key action VANY Increase Increase Increase Increase decrease the decrease the decrease the decrease the test voltage in test voltage in test voltage in test voltage in major steps major steps minor steps minor steps IR only IR only Button press During test VA AND V Sets voltage Show set to 500V voltage TA TV Increase Display set time Select main Display time decrease the on main timer timer T1 or T2 set for main time of the briefly timer T1 or selected timer T2 briefly TA AND TV Reset timer to Display set Reset selected Display set zero time on main timer to zero time on main timer briefly timer brief
19. ly Mode Select Test Cycle through Mode IR modes Cycle through Cycle through results display results display of last test of current completed active test Record Turn recording Select On Off download or clear stored data VA and VV represent the test voltage buttons TA and TV represent the timer buttons TEST MODE SUMMARY Press the MODE button to cycle through and select the test mode Modes of test to be chosen from include an insulation resistance IR test a polarization index PI test a step voltage SV test and a dielectric discharge DD test If timers T1 and T2 are set the instrument will automatically calculate the dielectric absorption ratio DAR of the insulation PI DAR and IR values are automatically stored and displayed if the data is available irrespective of the selected test mode At the end of a test the instrument can be made to display either the insulation resistances insulation currents or ratios plus capacitance measurements by using the Q T toggle button See section Q I button for cycling through results and toggling units Insulation Resistance IR test This is the default mode in which the instrument powers up This test mode measures insulation resistance continuously at the selected voltage The test voltage may be varied during an IR test by pressing the test voltage A or V buttons The test duration can be set using the main timer Th
20. n press and release the mode button repeatedly until the desired mode is indicated by the flashing symbol on the display Release the function button to select it In the breakdown mode the Breakdown Indicator will be illuminated refer to page 6 In this mode the test will automatically terminate should the insulation break down to prevent damage to the insulation under test In the burn mode the Burn Indicator is illuminated refer page 6 The burn mode disables the normal breakdown detection and enables the insulation test voltage to continue even after breakdown of the insulation This will enable the location of the failure to be seen and heard Due to the potential damage that could occur the unit produces two long beeps when starting a test with burn mode activated Alarm limit mode The insulation resistance IR test has an option of setting an alarm limit If this mode is selected the instrument will beep should the resistance reading exceed a user selectable threshold To set the limit hold down the function button then press and release the mode button repeatedly until the A symbol is flashing on the display Use the timer A and Y buttons 15 to set the resistance threshold between the limits of 10 kQ and 15 TQ Release the function button to save the current limit Adjusting the alarm threshold level automatically activates the alarm limit mode This is indicated by the A 1 symbol turning solidly
21. on To toggle the alarm limit mode on off hold down the function button then press and release the mode button repeatedly until the A t symbol is flashing on the display Release the function key to toggle Step voltage SV test This is a test based on the principle that an ideal insulator will produce identical readings at all voltages while an insulator which is being over stressed will show lower insulation values at higher voltages The main timer and test voltage settings can be adjusted if desired from their default values of 5 minutes and 1 kV respectively During the test the applied test voltage incrementally steps by one fifth of the test voltage setting final value every minute for 5 minutes taking successive measurements until the final voltage is reached Readings for the first 4 recorded values are displayed under the consecutive segment headings 1m to 4m The 5 minute reading is displayed by the main display If the range of measured insulation between readings is too wide for the instrument to display then those readings too small compared to the final reading will be represented by Polarisation index PI test and dielectric absorption ratio DAR test The PI test is a particular example of a time resistance method which takes the ratio of the insulation measured at 1 minute and at 10 minutes Good insulation generally shows an increase in resistance over a 10 minute period
22. r on the surface of the instrument may lead to erroneous results It is recommended that the instrument is not used in wet weather conditions m This instrument is not intrinsically safe and must not be used in hazardous atmospheres NOTE THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS CONTENTS Safety warnings 2 Pre Test during test key action table 14 Introduction 4 Test mode summary 15 General description 4 Insulation resistance IR test 15 Features 4 Breakdown mode burn mode 15 Cleaning 4 Alarm limit mode 15 Power lead and battery charging 5 Step voltage SV test 16 Instrument controls and indicators 6 Polarisation index PI test and dielectric absorption Power On Off button 7 ratio DAR test 16 Test voltage A and W buttons 7 Dielectric discharge DD test 16 Test start stop button 7 Specifications 18 Q I button 7 Accessories 19 button 10 Repair and warranty 20 Fn button 10 Mode button 10 Symbols used on the instrument are Timer A and W buttons 11 Record button 11 A Caution risk of electric shock Recording to on board memory 11 A Gui Downloading tesuls 1 aution refer to accompanying notes Deleting results 11 c Equipment protected throughout by Double Recording to a PC 11 Insulation Class IT Migh voltage warning IED ao C Equipment complies with current EU directives Line input present LED 12 U Test terminals 12 Guard terminal 12 RS232 USB connection
23. s 12 Terms used in this manual Battery bar graph 13 The word must is used to indicate that the instructions tollowing should Nlape at terminals 13 be followed under all circumstances Failure to follow these instructions Timer indicator 13 could result in damage to the instrument and or a hazard to the operator Digital display 13 The word should is used to indicate that the instructions indicate best Analogue display 14 practice Secondary display 14 INTRODUCTION General Description The MIT520 is a microprocessor controlled 5 kV insulation tester offering measurement capability of up to 15 TQ The instrument performs automatic tests and has data storage and data retrieval facilities Polarization index and dielectric discharge tests are performed automatically and test duration and voltages can be adjusted according to user preference for these tests A step voltage test can be performed automatically with a default voltage of 1 kV and test duration of 5 minutes It is possible for the user to set different voltages and test durations for the step voltage test The MIT520 can be powered from the mains supply or by its own internal rechargeable battery which provides for at least 6 hours of continuous testing A battery level indicator on the LCD display indicates battery capacity Connecting power to the mains supply connector will automatically charge the battery whether the instrument is switched on or off A high level of
24. s disabled 00 00 T1 cannot exceed the time on T2 Record button This button is used to start and stop recording Recording can only be activated before testing When data recording is enabled the record symbol flashes Data is stored in solid state memory and under normal circumstances will maintain its integrity for in excess of ten years but may rarely be corrupted or lost by external influences such as transients and static discharge Megger Limited cannot accept responsibility for any losses of data Regular downloading to a PC using software such as Download Manager will substantially reduce any such risk Recording to on board memory Press the record button to start and stop recording When data recording is enabled the record symbol will flash on and off repeatedly Recording can only be activated before testing commences Results are stored at 15 30 45 and 60 seconds After 60 seconds at minute intervals up to 10 minutes After 10 minutes results are recorded at 5 minute intervals until the test terminates At each interval the recorded data will contain selected voltage test time elapsed voltage applied leakage current and insulation resistance Downloading results Connect the instrument to the RS232 USB port of a PC running Download Manager Refer to section RS232 USB connection for set up details Start Download Manager on your PC select the MIT520 MIT1020 driver and right click the icon Select
25. s power is present the indicator shows the battery is being below Fully charged battery 50 charged battery Some testing still possible but battery may fail at any time Symbol flashes when there is not enough charge for a test The charged by animating the segments of the bar graph Voltage at terminals The test voltage will default to that selected in the previous test If the instrument has been switched off since the previous test the test voltage defaults to 250 V If there is an external voltage greater than 50 V present this will be displayed regardless of changes made to the test voltage In this case the instrument will not perform a test The high voltage warning indicators flash to warn of the hazard until the external voltage becomes less than 50V When testing the voltage displayed is the voltage present at the test terminals of the instrument If the test voltage is changed by pressing either of the test voltage A and V buttons during a test the new test voltage is displayed momentarily After testing the voltage displayed is the voltage present on the terminals To see what the voltage was immediately prior to the end on the test press either test voltage A or V buttons Timer indicator The timer shows minutes and seconds At the start of a test the timer will start from zero and at the end of a test it will stop The duration of the last test remains on the display until another test is started Dig
26. se of the guard causes the current flowing through surface leakage to be diverted from the measuring circuit The instrument therefore reads the leakage of the insulator ignoring leakage across its surface The display will show FUS if the internal guard terminal fuse is found to have blown The instrument must be switched off to clear the message before further testing is permitted The fuse should be replaced by an authorised repairer The instrument may be used in the mean time if the guard terminal not used RS232 USB connection Data can be transferred to a PC via an RS232 or USB port If using the RS232 port use the null modem cable supplied The RS232 settings are 38400 Baud 8 data bits 0 parity 1 stop bit no flow control handshake If using the USB port ensure that the USB driver supplied on the accompanying product CD has been installed BEFORE connecting the instrument Installation instructions are also to be found on the CD Programmes such as Megger Download Manager may be used to download the results stored in memory Programmes such as hyper terminal may be used to record real time data Battery bar graph This is a battery symbol on the LCD display comprising 4 pairs of segments The battery is monitored continuously when the instrument is turned on The charge remaining in the battery is shown in the table AULT Ie LU MUR UR LIN MP III instrument then turns itself off f f FfIN w When main
27. to Megger Copies of the original purchase invoice and packing note should be sent simultaneously by airmail to expedite clearance through customs In the case of instruments requiring repair outside the warranty period an immediate quotation can be provided when obtaining the RA number 5 You may track the progress of your return on line at www megger com Approved Service Centres A list of Approved Service Centres may be obtained from the UK address above or from Megger s website at www megger com Megger Limited Archcliffe Road Dover Kent CT17 9EN England T 44 0 1 304 502101 F 44 0 1 304 207342 E uksales megger com Megger 4271 Bronze Way Dallas Texas 75237 1019 USA T 1 800 723 2861 USA ONLY T 1 214 333 3201 F 1 214 331 7399 E ussalesemegger com Megger products are distributed in 146 countries worldwide This instrument is manufactured in the United Kingdom The company reserves the right to change the specification or design without prior notice Megger is a registered trademark Part No MIT520 UG en VO1 WK80106 www megger com Megger Z A Du Buisson de la Couldre 23 rue Eug ne Henaff 78190 TRAPPES France T 33 0 1 30 16 08 90 F 33 0 1 34 61 23 77 E infosemegger com Megger Pty Limited Unit 26 9 Hudson Avenue Castle Hill Sydney NSW 2125 Australia T 61 0 2 9659 2005 F 61 0 2 9659 2201 E ausalesemegger com Megger Megger Limited 110 Milner Avenue Unit 1 Scarborough Ontar

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