Bushing failure is one of the leading cause of transformer failure, accounting for 15% of the total failures. Faulty insulation is the principal cause of bushing failure. Humidity and oil aging are major factors in insulation breakdown. The traditional system of bushing checking is based on measuring the dielectric loss of insulation, also known as the dissipation factor, at a voltage of 10 kVA at the power system frequency, disconnecting the transformer from the power system. With the introduction of BMT-330 by EPESOL, now on-load bushing monitoring is also possible. The advantage of on-load bush monitoring is that it can be carried out with the transformer in-service condition and does not require an outage of what is often a piece of critical equipment.