Megger presents an advanced instrument capable of identifying nearly all types of cable fault using Time Domain Reflectometry (TDR) and Automatic Resistance Bridge techniques.
Megger’s BTDR1500 cable fault locators offer a TDR measurement range of 10m-3km while the Automatic Resistance Bridge function has a measurement range of up to 100km.
The cable fault locators feature a built-in insulation tester, DC voltmeter and loop resistance meter, and are suitable for telecom, coax, datacom and power cables. The instrument is also dust and shower-proof to IP54 requirements.
Offering a higher range capability, the Megger BTDR1500 TDR fault locator enables location of open circuits and low resistance faults from 0.1m to 3000m in length with a measurement accuracy of 1%.
The Automatic Resistance Bridge facility in the cable fault locators can be used to locate faults on cables up to 100km in length with a measurement accuracy of 0.2%.
The BTDR1500 cable fault locators in TDR mode can be used on any cable consisting of at least two insulated metallic elements, one of which may be armouring or the cable screen.
The instrument can be carefully matched to the cable using the Tx Null control allowing testing of long cable lengths and elimination of ‘dead zone’ so that faults close to the instrument can also be seen.
The propagation velocity value can be similarly adjusted to match the cable, ensuring direct reading of accurate distance measurement. A wider range of faults can be detected in TDR mode since the gain of the instrument is also variable, allowing more minor faults to be identified over the entire length of the cable.
The Automatic Digital Bridge can measure insulation resistance up to 200 M½ (insulation test), loop resistance up to 2 k½ (2-wire loop test) and series leg resistance of up to 1 k½ (3-wire loop test).
Where a fault causes the insulation resistances to be below 20 M½, the fault position can be determined relative to the meter end and also relative to the far end where a loop has been made by fitting a strap between the wire under test and one or two return wires.
In the case of a single return wire (2-wire test method), the position of the strap is assumed to be at the position of half the total loop resistance. If two return wires can be used (3-wire test method), the position of the strap will be known to greater accuracy and will be independent of the resistance of either of the return wires.
The BTDR1500 cable fault locators also have a voltmeter range for measuring DC voltage to ±250 V and can verify if a telecom cable has Telecom Network Voltage (TNV) present on it.