Biddle CFL535F_UG 电路图.pdf

Cable Fault Locator MEGGER CFL535F User Guide MEGGER CFL 535F english 4/1/02 9:21 am Page 1 RadioFans.CN 收音机爱 好者资料库 SAFETY WARNINGS This instrument meets the safety requirements of IEC 61010 part 1 to 300V CAT III. Although this tester does not generate any hazardous voltages, circuits to which it can be connected could be dangerous due to electric shock hazard or due to arcing (initiated by short circuit). While every effort has been made by the manufacturer to reduce the hazard, the user must assume responsibility for ensuring his or her own safety. For use on energised systems rated up to 300V Installation Category III* use the fused clip set AVO Part Number 6111-218, must be used. * Relates to the transient over voltages likely to be met in fixed wiring installations. CAUTION (Risk of electric shock) 4mm plug to BNC Adaptor: This 4mm plug to BNC adapter is intended for use with telecomm network cables only, it is not designed or intended for direct connection to an energised mains supply. However, in normal use it may be subject to telecom network voltages (TNV) as defined by IEC 60950 3rdedition (1999-04). The BNC plug and socket are, by necessity, accessible. The outer sheath for this connector is normally at SELV levels, however under single fault conditions it may carry hazardous voltages. The operator must therefore verify that the accessible plug or socket is at SELV levels prior to touching, or alternatively wear appropriate insulated gloves. The instrument should not be used if any part of it is damaged. Test leads and crocodile clips must be in good order, clean and with no broken or cracked insulation. Check that all lead connections are correct before making a test. A Fused Lead Set must be used to connect to energised live systems. Refer to the accessories section for options. Disconnect the test leads before accessing the battery compartment. Refer to operating instructions for further explanation and precautions. Safety Warnings and Precautions must be read and understood before the instrument is used. They must be observed during use. 2 NOTE THE INSTRUMENT MUST ONLY BE USED BY SUITABLY TRAINED AND COMPETENT PERSONS. CFL 535F english 4/1/02 9:21 am Page 2 RadioFans.CN 收音机爱 好者资料库 Saving a trace to memory Recalling a trace from memory Downloading a trace to a PC Uploading stored trace from PC to TDR Techniques for Improving Accuracy14 Test the cable from both ends Care and Maintenance15 Specification15 Accessories17 Repair and warranty18 Symbols used on the instrument are: Caution: Refer to accompanying notes. Equipment protected throughout by double or reinforced insulation. Instrument flash tested to 3.7kV rms. Equipment complies with current EU directives. Contents 3 Safety Warnings2 Introduction4 User Display the second, a short circuit at 1.200km away. CFL 535F english 4/1/02 9:21 am Page 11 If the velocity factor of the cable under test (C.U.T) is not known, it may be accurately established by: Testing a known length of cable, locate the reflection for the end of the cable on the display. Use the shortest possible range setting. Use the ZOOM button to accurately position the distance cursor. Adjust the velocity factor of the TDR using the VF key (4) until the TDR displays the correct length of cable. Make a note the VF value for future reference. The table of velocity factors in the HELP pages of the instrument is a rough guide and in practice, the settings are subject to many variable factors. By using the previous procedure on a known length of cable, a more accurate VF can be established. The measurement of the distance to the fault can now be made with more confidence that the measurement will be correct. The ability of the instrument to accurately measure the distance to a cable feature relies on the velocity factor being correct, any errors in the velocity factor are directly proportional to distance measurement errors. Hence, the instrument uses the velocity factor to three decimal places to reduce any errors. Pulse Widths As the RANGE of the TDR is adjusted (Key 11) so the duration of the transmitted pulse changes. Each of the instrument ranges has a default pulse width. The pulse widths vary from 7 ns to 16 s. The greater the range set on the TDR, the wider the transmitted pulse. At short range, a short pulse width will have good resolution. As Instrument Features 12 Tx Null Without the “Tx Null” control, the transmitted pulse would be visible at the beginning of the trace, swamping any reflections within the pulse length (the dead zone). The Tx Null circuit matches the characteristic impedance of the cable under test to produce an equivalent pulse. Subtracting this equivalent pulse from the transmitted pulse effectively removes the dead zone from the display and allows “near end” reflections to be seen. NOTE: In some cases, it will be impossible to completely null the transmitted pulse. Alternatively, using the L1-L2 mode, where L2 is connected to a known good length of the cable under test, L2 is used instead of the balancing circuit to automatically null the transmitted pulse. In this case only the difference between the good line and the bad line will be displayed. 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 can be displayed as a ratio of the speed of light (eg 0.660 = 66% of the speed of light), or as a distance per microsecond in ft/us or m/us. No Tx NullAdjusted Tx Null CFL 535F english 4/1/02 9:21 am Page 12 Recalling a trace From any of the display modes L1, L2, L1 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 3 YEARS 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: AVO INTERNATIONAL orAVO INTERNATIONAL Archcliffe Road Valley Forge Corporate Centre Dover 2621 Van Buren Avenue Kent, CT17 9EN.Norristown, PA 19403 England.U.S.A. Tel: +44 (0) 1304 502243Tel: +1 (610) 676-8579 Fax: +44 (0) 1304 207342 Fax: +1 (610) 676-8625 or an approved repair company. CFL 535F english 4/1/02 9:21 am Page 18 19 CFL 535F english 4/1/02 9:21 am Page 19 This instrument is manufactured in the United Kingdom. The company reserves the right to change the specification or design without prior notice. MEGGER is the registered Trade Mark of AVO INTERNATIONAL LIMITED. Copyright, AVO INTERNATIONAL LIMITED Part No. 6172-663 Edition 1 Printed in England 06GG AVO INTERNATIONAL Archcliffe RoadPO Box 90074271 Bronze WayMEGGER SARL DoverValley ForgeDallas29 Alle de Villemomble Kent, CT17 9EN.PA 19484-9007TX 75237-101793340 Le Raincy England.U.S.A.U.S.A.Paris, France Tel: +44 (0) 1304 502100Tel: +1 (610) 676-8500Tel: +1 (800) 723-2861 (U.S.A. only)Tel: +33 (1) 43.02.37.54 Fax: +44 (0) 1304 207342 Fax: +1 (610) 676-8610 Tel: +1 (214) 330-3203 (International)Fax: +33 (1) 43.02.16.24 Fax: +1 (214) 337-3038 CFL 535F english 4/1/02 9:21 am Page 20