As transformers age their internal condition degrades, increasing the risk of failure.When a transformer is new it has sufficient electrical and mechanical strength to withstand unusual system conditions. As transformers age, their insulation strength can degrade to the point that they cannot withstand system events such as short-circuit faults or transient overvoltages.
To prevent failures and to maintain transformers in good operating condition it is very important to perform preventative maintenance programs combined with regular testing.
In order to test for a transformer’s internal condition, it is necessary to remove it from its tank. However, this method can be tedious and take too much time. A more practical method is to use a sweep frequency analyzer.A sweep frequency response analyzer lets you diagnose the internal condition of a transformer by injecting an excitation signal and analyzing the spectrum bounced back by the windings. This is a more efficient way of detecting core and winding problems.
One of the most popular test sets used is the Doble M5400 Sweep Frequency Response Analyzer. The Doble M5400 has an output voltage of 20 Volts peak-to-peak at 50 Ohms output impedance. With input circuitry that can analyze difference, cross-relation and sub-band at frequencies from 10 Hertz to 25 MegaHertz, the Doble M5400’s bandwidth is more than sufficient in analyzing common problems in transformers.
The Doble M5400 also features a sampling rate of 100 MS/s with a dynamic range of >90 dB.
Planning on investing on a Doble M5400 Sweep Frequency Response Analyzer? Consider renting from Protec Equipment Resources first. This allows you to evaluate the Doble M5400’s features to ensure it meets your specific needs.