Spot Issues in Transformers Before They Get Worse

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Transformer windings are prone to failure due to excessive heat exposure during operation. The heat causes the windings to expand and can weaken them. Transformers should be regularly tested to prevent unexpected failures and electrical hazards.


Hipot testing is a common test done in transformers. This method applies a test voltage and holds it for a specified amount of time. However, this method only tests the integrity of the insulation and does not detect changes in the windings.  A short circuit test is the preferred test to detect issues that are just starting. This test works by shorting the secondary windings and applying an excitation test voltage to the primary windings. The absorbed power by the windings’ leakage reactant is measured. This data will be compared to its factory specifications. This method is better compared to 
AC Hipot testing in finding minor faults. This lets technicians address issues before they get worse. The M4110 from Doble test instruments is commonly used for this application. It has features that allows you to test most high voltage transformers.

You can get testing instruments for transformers from Protec. To reduce maintenance costs, you can opt to rent than buy the test equipment you need. Call us at 866-352-5550 for information on rental packages, payment options and available equipment.