CET Measuring a transformer's DC resistance from one external terminal to another can reveal a great deal of information about the transformer. Hence, the integrity of all these components can be verified. It is assumed the operator has sufficient knowledge of electrical theory and safe working practices to use the test instrument in a safe and responsible manner. Installation Risk of damage is significant whenever a transformer is moved. This is inherent to the typical transformer design and modes of transportation employed.
Damage can also occur during unloading and assembly.
The damage will often involve a current carrying component such as the LTC, RA switch or a connector. Damage to such components may result in a change to the DC resistance measured through them. If the transformer is new the resistance test also serves as a verification of the manufacturers work. Installation measurements should be filed for future reference. Transformer Maintenance Routine maintenance is performed to verify operating integrity and to assure reliability.