M TDR1000/3 TDR1000/3P CFL510G TDR500/3 Time Domain Reflectometers User Manual Page 1 of 1
CONTENTS Introduction ...........................................................................................................................................................................................................5 Overview.................................................................................................................................................................................................................7 Instrument layout and display ....................................
G SAFETY WARNINGS ■ Safety warnings and precautions must be read and understood before the instrument is used. All Safety warnings and precautions must be observed during use. ■ The circuit under test must be switched off, de-energised, securely isolated and proved safe before test connections are made. ■ Use the correct lead set. On power systems the Megger fused lead set must be used. Refer to the Test Lead selection page in this user guide to identify the correct lead set.
Symbols The following symbols are used on this instrument G CAUTION: RISK OF DANGER t EQUIPMENT PROTECTED THROUGHOUT BY DOUBLE INSULATION OR REINFORCED c INSULATION EQUIPMENT COMPLIES WITH RELEVANT EU DIRECTIVES EQUIPMENT COMPLIES WITH AUSTRALIAN EMC REQUIREMENTS (C-tick) (NOT FOR SAFETY) THIS EQUIPMENT SHOULD BE RECYCLED AS ELECTRONIC WASTE Page 4 of 4
Introduction Thank you for purchasing this cable fault locator. Before attempting use of your new instrument please take the time to read this user guide, ultimately this will save you time, advise you of any precautions you need to take and could prevent damage to yourself and the instrument. This is an advanced instrument capable of identifying a wide range of cable faults. The instrument uses a technique called Pulse Echo (also known as Time Domain Reflectometry or TDR).
The instrument can be used on any cable consisting of at least two separate conductive elements, one of which may be the armouring or screen of the cable. It has internal matching networks to allow testing of 25 Ω, 50 Ω, 75 Ω and 100 Ω cables. (These typically correspond to power, coaxial data and data/telecoms cable). By selecting the TDR impedance closest to that of the cable under test, maximum power can be transmitted into the cable allowing long cables to be tested.
Overview Instrument Layout & Display Left & Right Arrows used in setup Backlit 256 x 128 dot matrix display Backlight Four Way Joy Switch Mainly controls range and cursor There is an audible tone on key presses. A low tone means the key is invalid Hold key Rotary Switch Turn to OFF to switch the instrument off.
Velocity Factor Display Impedance Range Battery State Indication Cursor 2 Cursor 1 Hold Indicator Cursor 1 Position Distance Between Cursor 1 & 2 Cursor 2 Position Page 8 of 8
Controls Rotary Switch Turn the switch from OFF to another position to turn the instrument on. The instrument may be turned off, by switching to OFF, or the instrument may switch itself off if it has not been used for 5 minutes or the battery is exhausted.
Range & Cursor Control The range is set using the four way switch; press up to increase the range and down to reduce the range. Moving the four-way switch left or right will move the active cursor.
Backlight & Hold Backlight key. Press the backlight key to switch the backlight on. It will switch off after one minute with no key press when activated, or it may be switched off by pressing the key again Hold key. When the rotary switch is set to cursor 1, cursor 2, or Auto, pressing the hold key will place an image of the current trace in grey on the display. This allows comparisons to be made between two cables or intermittent faults to be seen.
Setup The setup position allows the Velocity Factor, Impedance, Pulse Width, Gain, Distance Units, Sound and Display Contrast to be set. These are remembered when the instrument is switched off and recalled when switched back on. To adjust any of these parameters turn the rotary switch to the setup position. The parameter to be adjusted is highlighted at the top of the screen. Pressing the left or right key will select a different parameter; using the four-way joy switch will change the parameter.
Operation General Testing procedure Ensure the correct test leads are firmly fitted into the sockets of the instrument. Switch on the instrument. The instrument will display the start screen for a couple of seconds, followed by a trace. The instrument will remember the settings last used. If necessary, adjust the display contrast and distance units to the preferred settings. Use the setup mode to set the velocity factor and impedance of the cable about to be tested.
Connection to Cable Under Test Connect the test lead to the cable under test. Connection may be made to a live power system with a voltage to earth (ground) less than 150 V with an installation (over voltage) category of I V or lower. This means that the instrument may be connected to any to primary supply circuits such as overhead cables. The voltage must be less than 300 V between the terminals and 150 V CAT IV to earth. The fused lead set must be used to connect to power systems.
The 4mm plug to BNC adapter accessory is for use on cable distribution systems and low voltage cables only. The operator must verify that the circuit is safe for testing and take the appropriate precautions. In the event of no reflections being visible, increase gain in setup mode until any reflection can be easily identified. (If no reflections can be seen, try shorting or earthing the far end of the cable to ensure that you are “seeing” the whole length of the cable).
Velocity Factor The velocity factor is used by the instrument to convert the measured time for a pulse to be reflected, into a distance. It is displayed as a ratio of the speed of light (eg 0.66 = 66% of the speed of light).
Pulse Widths As the range of the TDR is adjusted so the duration of the transmitted pulse changes. The pulse width range varies from 2 ns to overcome signal attenuation and enable the instrument to see further down a length of cable. The greater the range selected on the TDR, the wider the transmitted pulse. The accuracy of the “distance to fault” is not affected by the length of the pulse.
Techniques To improve on the accuracy of the measurement, numerous techniques can be used, depending on the situation encountered. Not every situation can be described, but the following points are effective and the most common and easily implemented methods. Test the cable from both ends When fault finding on a cable it is good practice to take measurements from both ends, particularly in the case of open circuit faults, when the true end of the cable is not visible.
Battery Battery Replacement 2 - Undo Screws x 2 1 - Disconnect Leads Switch off the instrument Disconnect the instrument from any electrical circuits Undo two screws Remove the battery cover from the base.
Battery type: 5 x 1.5 V Alkaline LR6 (AA) or NiMH HR6 rechargeable. The crossed out wheeled bin placed on the batteries is a reminder not to dispose of them with general waste at the end of their life. Alkaline and NiMH batteries are classified as portable batteries and must be disposed of in accordance with local regulations. For details contact your local distributor.
Specifications Except where otherwise stated, this specification applies at an ambient temperature of 20 ºC General Ranges: 10 m 30 ft 25 m 75 ft 100 m 300 ft 250 m 750 ft 1000 m 3000 ft 2500 m 7500 ft 5000 m 15000 ft Accuracy: ±1% of range ± pixel at 0.67VF [Note- The measurement accuracy is for the indicated cursor position only and is conditional on the velocity factor being correct.] Resolution: 1% of range Output pulse: 5 volts nominal peak to peak into open circuit.
Safety When using the Fused Test Lead Set this instrument complies with EN 61010-1 for connection to live systems with less than 300V between the terminals and 150V CATIV to earth. When using the Miniature clip Test Lead Set, Bed of Nails Test Lead Set or BNC Adapter the system is rated for safety low voltage systems only.
Waste electrical and electronic equipment WEEE The crossed out wheeled bin placed on Megger products is a reminder not to dispose of the product at the end of its life with general waste. Megger is registered in the UK as a producer of electrical and electronic equipment. The Registration Number is WEE/HE0146QT. Megger is registered in the UK as a producer of batteries. The Registration Number is BPRN00142.
Ordering Information Item TDR1000/3 Time Domain Reflectometer includes Miniature clip test lead set TDR1000/3P Time Domain Reflectometer includes fused test lead set CFL510G Time Domain Reflectometer includes Bed of Nails test lead set and BNC adapter Accessories User information CD Hard carry case Miniature clip test lead set Bed of nails test lead set Fused test lead set BNC adapter Order No.
Test Lead selection Fused test lead set Megger Part Number 1001-717 must be used on power systems Other test leads and the BNC adapter must only be used on low voltage systems Page 25 of 25
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.
CALIBRATION, REPAIR AND SPARE PARTS For service requirements for Megger Instruments contact: Megger Limited Archcliffe Road Dover Kent CT17 9EN England. Tel: +44 (0) 1304 502 243 Fax: +44 (0) 1304 207 342 Megger operate fully traceable calibration and repair facilities, ensuring your instrument continues to provide the high standard of performance and workmanship you expect.
Returning your product to Megger - UK and USA service centres 1. When an instrument requires calibration, or in the event of a repair being necessary, a Returns Authorisation (RA) number must first be obtained from one of the addresses shown on the following page. 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. Model, e.g.
M Megger Limited Archcliffe Road Dover Kent, CT17 9EN England Tel: +44 (0) 1304 502100 Fax: +44 (0) 1304 207342 Megger SARL Z.A. Du Buisson de la Couldre 23 rue Eugène Henaff 78190 TRAPPES France Tel : +33 (1) 30.16.08.90 Fax : +33 (1) 34.61.23.77 Megger 4271 Bronze Way Dallas TX 75237-1017 U.S.A. Tel: +1 (800) 723-2861 (U.S.A.
