Skip to main content
Published on

Taking the Guesswork out of Resistive Fault Location


If you didn’t know already, resistive-fault-location (RFL) testing consists of a powerful measurement that is capable of locating high-resistive faults on copper pairs. Although there are other methods for determining fault location, notably time-domain reflectometry (TDR), this particular measurement typically requires an extremely low-resistance fault (e.g., <100 Ω) in order to be reliable.

High‑resistive faults are generally caused by damage or deterioration of cable insulation (or the sheath protecting the wires) due to the presence of water or moisture, which is usually the result of human or animal interference.

Although resistive faults are a common source of broadband service impairment, when it comes to locating high-resistive faults, the TDR method is relatively ineffective. As such, an RFL test should be used to locate where a given contact fault is occurring in a cable pair. However, don’t be fooled: the RFL test may seem simple and straightforward at first glance, but in reality, experience is required to select the best methodology and parameters necessary for accurate fault location via RFL tests.

For details on all of the techniques, methods and tools needed to successfully locate faults accurately using the RFL method, check out our new Resistive Fault Location Reference Guide, which covers RFL and RFL-related issues, test setups and solutions in detail.