The magnetic balance test is used on three phase transformers to check core integrity and detect inter turn or inter phase faults. With the test, a single phase voltage is applied to one phase and induced voltages are measured in the other phases. In a healthy transformer, the measured voltages follow characteristic patterns depending on the connection group. Significant deviations indicate possible issues such as core damage, shorted turns or incorrect connections. It is a simple offline diagnostic that helps verify magnetic circuit symmetry after transport or repair.