Technical library

In branched low voltage networks, low-resistance faults, interruptions and large changes in impedance can only be located by comparing fault-free and defective cores.

The use of T-branches in low voltage networks makes the evaluation of TDR traces considerably more difficult. Only through comparative measurements of fault-free and defective wires can possible results be achieved. The test pulses of the Teleflex are partially reflected at the T-joint with a negative algebraic sign, while test pulses that continue are simultaneously reduced in amplitude. The amount of reflection depends on the impedance in the main line and the continuing line.

Overview of low voltage cable fault location test methods

There are multiple ways to find a cable fault in a low voltage network, but no one method works for all situations. It’s only by knowing the pros and cons of each method that you can determine the most effective one to use in any given scenario and pinpoint the fault in as little time as possible.

There are many different tests that can be performed on a battery string. The question often arises which one should be performed?

Megger’s SMRT Series of relay test sets has been engineered to offer a full range of testing solutions built around flexibility and customization. These test sets are ideally suited for testing today’s complex micro-processor relays as well as legacy electro-mechanical relays. The versatility of the SMRT Series is ideal for performing commissioning and periodic maintenance testing to help keep the power on.

Abstract-Switching operations and direct current applied during routine testing procedures of static winding resistance measurement leave residual magnetization in the core and/or fully saturate the core of the transformer.

After we gather impedance data, what do we do with it? How do we make sense of it? This paper answers these questions in detail.

Dielectric Frequency Response, DFR is the extension of power factor testing except that the measurement is performed from 1 kHz down to typically 1 mHz. It is a very useful tool for evaluating the moisture content in solid insulation of HV and EHV components such as power transformers, bushings, instrument transformers and PILC cables.

The measurement of winding resistance is useful in detecting a number of types of fault in a transformer. This application note discusses this in detail.