DET10C and DET20C Clamp on Ground
Contents
1. low battery symbol is displayed on the LCD replace the old battery with a new battery Remove instrument from test piece during battery change 1 Turn the switch to the OFF position 2 Unfasten the battery cover screw 3 Lift and remove the battery cover Remove the old battery 5 Install the new 9 V battery 6 Replace the battery cover and secure the screw Ce m CAT N GOOV CAT III 309V MEGGER LTD DOVER ENGLAND REPAIR AND WARRANTY The instrument circuit contains static sensitive devices and care must be taken in handling the printed circuit board If the protection of an instrument has been impaired it should not be used and be sent for repair by suitably trained and qualified personnel The protection is likely to be impaired if for example the instrument shows visible damage fails to perform the intended measurements has been subjected to prolonged storage under unfavourable conditions or has been exposed 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 Instrument Repair and Spare Parts For service requirements for Megger Instruments contact Megger Limited or Megger Archcliffe Road Valley Forge Corporate Center Dover 2621 Van Buren Avenue Kent CT17 9EN Norristown England PA 19403 U S A Tel 44 0 1304 502243 Tel2. upper row of the LCD the data is shown in the lower row of LCD N Press the A button to read the next data record 3 Holding down the A button accelerates the rate of increment The record number will roll over to 1 when the last record is reached Clearing the Data Memory With the instrument powered down press and hold the FUNC button then turn the power on The symbol CL will be shown to indicate that memory is cleared H Enabling the RS 232C output DET20C only To save battery power the default condition is RS 232C output disabled To output data to a PC continuously the RS232C can be enabled by the following procedure 1 Press the FUNC button until the symbol 232 is shown on the upper row of LCD 2 If the RS 232C output is enabled the symbol will follow the symbol 232 Press the A button to toggle the status of RS 232C output 3 To exit this function press the FUNC button several times until the upper row on the LCD is blank ede ede Disabled Enabled NOTE The RS 232C output interval is also specified by the sampling interval If the sampling interval is set at 0 seconds data is outputted every 0 5 seconds NOTE The RS 232C output is automatically disabled if data logging is in progress Installation of Megger Download Manager Software DET20C The DET20C instrument is supplied as standard with Megger Download Manager on CD 1 Hardware and Software Requirements The requirements are
3. 1 610 676 8579 Fax 44 0 1304 207342 Fax 1 610 676 8625 Returning an Instrument for Repair If returning an instrument to the manufacturer for repair it should be sent freight pre paid to the appropriate address A copy of the Invoice and of the packing note should be sent simultaneously by airmail to expedite clearance through Customs A repair estimate showing freight return and other charges will be submitted to the sender if required before work on the instrument commences Megger Megger Limited Megger Megger Archcliffe Road Dover 4271 Bronze Way Dallas Z A Du Buisson de la Couldre Kent CT17 9EN ENGLAND TX 75237 1019 USA 23 rue Eug ne Henaff T 44 0 1 304 502101 T 1 800 723 2861 78190 TRAPPES France F 44 0 1 304 207342 T 1 214 333 3201 T 33 1 30 16 08 90 F 1 214 331 7399 F 33 1 34 61 23 77 OTHER TECHNICAL SALES OFFICES Toronto CANADA Sydney AUSTRALIA Madrid SPAIN Mumbai INDIA and the Kingdom of BAHRAIN 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 DET10_20C_UG_V01 Printed in England 0604 www megger com
4. AL SPECIFICATIONS ACCESSORIES BATTERY REPLACEMENT 9 10 10 10 11 13 14 14 15 FEATURES DESCRIPTION The clamp on ground resistance tester enables the user to measure the ground resistance of a ground rod without the use of auxiliary ground rods The clamp on ground resistance tester is used in multi grounded systems without disconnecting the ground under test Megger DET20C Digital Earth Test Clamp FEATURES DESCRIPTION Wn 6 Jaws Assembly Encircle electrode or ground rod No air gap is allowed between the two jaw halves Hold Button Maintains last measurement on display Rotary Switch Power on and function selection LCD panel REC A button Function dependant on mode Starts either data logging single measurement recording or data download to PC Also used to increment a value in conjunction with FUNC button FUNC button Press to select HI high alarm LO Cow alarm SEC recording interval dL Data down load no Read Data or 232 RS 232C Jaws opening lever Battery cover RS 232C interface connection point DET20C only LIQUID CRYSTAL DISPLAY 1 Function 2 Digits 3 Ohm 4 mA 5 oa 6 NOISE 7 Jaw Open 8 Low Battery 9 NO 10 REC 11 H 12 AP Display current selected function or current record number Display value from 0 to 9999 with decimal point Indicates resistance mode and alarm functions Indicates gr
5. Current Auto range 50 60 Hz True RMS Crest Factor lt 3 5 Range Resolution Accuracy of Reading 0 200 1 000 mA 0 001 mA 2 0 0 05 mA 1 00 10 00 mA 0 01 mA 2 0 0 03 mA 10 0 100 0 mA 0 1 mA 2 0 0 3 mA 100 1000 mA 1 mA 2 0 3 mA Ground Leakage Current 50 60 Hz True RMS Crest Factor lt 3 5 Range Resolution Accuracy of Reading 0 20 35 00 A 0 01 A 2 0 0 03 A Accuracy of Resistance Calibration Plate 1 Data Logging Capacity 8180 records DET20C 116 records DET10C Data Logging Interval 1 to 255 seconds RS 232C Output 0 5 and 1 to 255 seconds GENERAL SPECIFICATIONS Conductor Size 35 mm 1 36 approx Battery Type 9V IEC 6 LR61 Alkaline Display Type 4 digits 9999 counts LCD Range Selection Auto Overload Indication OL Power Consumption 40 mA Low Battery Indication Battery Life 3000 measurements Auto Power Down 5 minutes approx Sampling Time 0 5 seconds Operating Temperature 0 C to 50 C 14 F to 122 F Operating Humidity Less than 85 RH Storage Temperature 20 C to 60 C 4 F to 122 F Storage Humidity Less than 75 RH Dimensions 276 mm L x 100 mm W x 47 mm H 10 8 L x 3 9 W x 1 9 D Weight 7509 1 65lbs ACCESSORIES Resistance Calibration Plate x 1 9V Battery Installed x 1 Users Manual x 1 Carrying Box x 1 Accessories DET 20C RS 232C Cable Megger Download Manager CD 12 BATTERY REPLACEMENT When the
6. FUNC button several times until the upper row LCD does not show any letters 5 When the rotary switch is set at the oo position the instrument will compare the measured value with the high and low values If the measurement is higher than the HI value the unit will beep and show HI in the upper row of LCD If the current measurement is lower than the LO value the unit will beep and show LO in the upper row of LCD HE TAO i i Li M A i NOTE If the HI value is set at OL or the LO value is set at 0 the ALARM function is disabled The HI or LO value can be disabled individually NOTE The HI value cannot be lower than the LO value Similarly the LO value cannot be higher han the HI value HI value will be adjusted to LO value plus 1 if roll over occurs The maximum value of LO value is HI value minus 1 NOTE If data logging is in progress the beeper will be disabled to save battery power However he LCD displays the warning letters of HI or LO if an alarm condition occurs NOTE The values for the high and low alarm are stored in the memory The values will be active when the unit is powered on and alarm mode selected Ground Leakage Current Measurement 1 Set the rotary switch to the mA or A position 2 Place the clamp around the electrode or ground rod to be measured 3 Read the value of leakage current displayed on the LCD Setting the Sampling Interval 1 Press the FUNC button until the lett
7. Megger DET10C and DET20C Clamp on Ground Resistance Tester User Manual A SAFETY WARNINGS m Use of rubber gloves is good safety practice even if the equipment is properly operated and grounded m Safety is the responsibility of the operator m Use extreme caution when using the instrument around energised electrical equipment Do not attempt to use the ground tester to twist or pry the ground electrode or ground wire away from the equipment being grounded m All metal objects or wires connected to the electrical system should be assumed to be lethal until tested the grounding system is no exception Symbols used on the instrument are AX Caution Risk of Electric Shock A Caution refer to accompanying notes o Equipment protected throughout by Double Insulation Class ID C EN 61010 2 032 CAT III 300V CAT II 600V Pollution Degree 2 CONTENTS SAFETY WARNINGS FEATURES DESCRIPTION CONTROLS DESCRIPTION LIQUID CRYSTAL DISPLAY OPERATING INSTRUCTIONS Ground Resistance Measurement High and Low Alarm oa Ground Leakage Current Measurement Setting the Sampling Interval Data Logging Downloading Data to a PC DET20C only Format of Down Loaded Data DET20C only Reading the Data Stored in Memory Clearing the Data Memory Enable RS 232C output DET20C only Installation of Megger Download Manager Software Description of Megger Download Manager Software PRINCIPLE OF OPERATION ELECTRICAL SPECIFICATION GENER
8. OTE For better measurement 1 Operate the jaws a few times before powering on to clear mating surfaces 2 Do not clamp on to any conductor during power up point 3 above 3 Operate the jaws a few times after clamping around the ground electrode NOTE If self calibration does not complete The instrument will continue the process until a successful self calibration is achieved 1 Check the jaw mating surfaces If there is any dirt dust or any foreign substance clean the surfaces 2 Ensure the jaws are not open during self calibration NOTE Noise present in the electrode or ground rod If there is excessive current or over 30V noise in the ground rod a symbol of NOISE will be shown in LCD Under these conditions the reading is no longer accurate We recommend the current flow is measured before a resistance reading is taken NOTE If jaws are opened during a measurement a symbol of OPEN will be displayed on the LCD High and Low Alarm 1 Set the rotary switch to the a position 2 Press the FUNC button to select HI or LO alarm The present value of High or Low alarm will be shown in the lower row of the LCD 3 Press the A button to increment the value by 1 ohm If the button is held down the rate of increment accelerates The value can be set from 0 ohm to 1550 ohm and then OL The value will roll over to 1 HD or 0 LO if the set value in incremented past OL 4 Once the value is set press the
9. d to Reg If a constant voltage is applied to the circuit the following equation is true then only R and Req are left in the circuit refer to Figure B V Ry Reg Req 1 1 i 1 2 N If Rg and Rj Rg R are similar values and n is a large number such as 200 then Req will be Where much less than R and approaches zero Rg gt gt Reg Req 0 Example If R and Rj Ra Ry are all 10 Q respectively and n 200 Then Req by calculation equals Req 1 0 050 1 41441 10 10 10 V Ry Req 10 0 05 10 05 O gt R In this example we can see that as long as the number of multiple electrodes is large enough the equivalent resistance is negligible with respect to the ground resistance to be measured oy a xD in ie j Figure A Figure B 11 ELECTRICAL SPECIFICATION Ground Resistance Auto range Range2 Resolution Accuracy of Reading 0 025 0 250 Q 0 002 Q 1 5 0 05 Q 0 250 9 999 Q 0 02 Q 1 5 0 1 Q 10 00 99 99 Q 0 04 Q 2 0 0 3 Q 100 0 199 9 Q 0 4 Q 3 0 1 0 Q 200 0 400 0 Q 22 5 0 5 Q 400 0 600 0 Q 5Q 10 10 Q 600 0 1500 Q 20 Q 20 1 Loop resistance non inductive external field lt 50 A m external electrical field lt 1 V m conductor centered in jaws 2 Resistance Measurement Frequency 1 667 KHz High and Low Alarm Range Resolution High Alarm 0 1550 Q 1Q Lo Alarm 0 1550 Q 1Q Ground Leakage
10. detailed on the rear of the sleeve containing the CD 2 Installation of the Program Insert the CD If the CD does not auto run when inserted in the drive click on START RUN select your CD drive and run START EXE from the CD Follow the instructions to install the program to PC Description of Megger Download Manager The Megger Download Manager is a 32 bit Microsoft Windows application which controls data transfer from your DET20C instrument using a specific driver The driver may be installed from the CD or from our website www megger com Download Manager receives data from the instrument and stores it in comma separated format files that can be viewed and edited with the free CSV Viewer programme included 10 Megger Download Manager features 1 Single step data download from the DET20C in CSV format 2 Files managed using standard Windows format 3 Powerful CSV Viewer included to view sort edit graph and print downloaded data 4 Compact driver files for quick and easy disk and internet updates 5 Full help facility NOTE For operation of the Megger Download Manager refer to the help menu included in the software NOTE Selecting the DET20C driver then clicking the Download button on the tool bar gives the procedure for data download from the instrument PRINCIPLE OF OPERATION Below is a simplified typical ground distribution system The equivalent circuit is shown in Figure A If Ry Rg R3 Ry are simplifie
11. ers SEC are shown on the upper row of LCD 2 The unit shows the current sampling interval in seconds 3 Press the A button to increment the value by 1 second If the button is held down the rate of increment accelerates The value can be set from 0 to 255 seconds The set value will roll over to 0 when the maximum value of 255 seconds is reached 4 Press the FUNC button several times until the upper row LCD does not show any symbols IEL NOTE The sampling interval is used for data logging and RS 232C output timing Data Logging The unit will start data logging if the REC A button is pressed and the symbol REC will be shown on the LCD Data will be recorded at the specified sampling interval Data logging will be stopped if the memory is full or the unit detects a low battery condition or the REC A button is pressed again NOTE With sampling time greater than zero the Auto Power Off feature is disabled in this mode NOTE If the sampling interval is set at 0 seconds one set of data is recorded To record the next set of data press the REC A button again The record number and REC symbol is displayed for approximately 1 second Downloading Data to a PC ASCII format DET20C only 1 Connect the RS 232C cable to the unit and a PC 2 Run any application software which can accept ASCII data 3 Press the FUNC button until the symbol dL is shown in the upper row on the LCD The number of records in the memory is sh
12. ound leakage current mode in mA or A Indicates instrument is set at the alarm position Indicates ground resistance tester senses noise or excessive current present in the ground electrode Displayed if the jaws are opened during the measurement this symbol and word OPEN will be shown in LCD Indicates battery voltage is lower than required Indicates the data record number in memory Indicates data logging is in progress Indicates HOLD function activated Indicates Auto Power Off activated Deactivate by holding down the REC button then turning on unit OPERATING INSTRUCTIONS Ground Resistance Measurement 1 Open the jaws and make sure that the mating surfaces are clean and free of dust dirt or any foreign substance 2 Snap the jaws a few times to ensure clean contact is made 3 Turn the rotary switch to the Q position to power the instrument on Do not clamp on to any conductor or open the jaws as this is a self calibration phase 4 At power on in _ mode the instrument will perform a self calibration for optimum accuracy Users must wait for self calibration to be complete before use During the self calibration phase the LCD will show CAL7 CAL6 CALS CAL4 CAL 3 CAL2 and CAL1 5 When the ground tester is ready a beep will be heard 6 Place the clamp around the electrode or ground rod to be measured Operate the jaws a few times for better accuracy 7 Read the value of Rg ground resistance from LCD N
13. own in the lower row on the LCD 4 Press the REC A button to down load all the data stored in the memory The symbol is shown next to the symbol dL when data is transferring to PC in ASCII format 5 The process of down loading can only be halted by turning the instrument off 6 To exit this function press the FUNC button several times until the upper row LCD shows no symbols NOTE The unit first sends the sampling time then the rest of the data stored in memory is sent to the PC at ai lt lt Format of Down Loaded Data DET20C only The data is down loaded to the PC in ASCII format In addition to data readings information includes status of jaws open noise HI alarm LO alarm and low battery Below is a list of abbreviations for each condition and an example of data down loaded to the PC List of abbreviations Abbreviation Abbreviation Abbreviation OPEN Jaws open NS Noise HI Hi alarm LO Low alarm HD Data Hold LB Battery low Example of down loaded data 0001 sampling time 10 00 ohm 10 02 ohm 5 200 ohm LO 1 000 ohm NS 1 500 mA 9 00 A NOTE Each record is ended by lt CR gt and lt LF gt The corresponding ASCII codes for lt CR gt and lt LF gt are 13 and 10 Reading the Data Stored in Memory This function allows users to read the data stored directly from the instrument display 1 Press the FUNC button until the symbol NO is shown on the LCD The current record number is shown on the
Download Pdf Manuals
Related Search