Bushing are relatively cheap (comparing to transformer value). Unfortunately, bushings breakdown failure often leads to catastrophic transformer failure like windings deformations. Due to materials imperfection weather conditions and stress bushings are prone to failure. Unfortunately, sometimes that failure escalates very quickly. Historically bushings were tested off-line to measure the capacitance and the dissipation / power factor.

The Bushing BMC Monitor is a permanently installed on-line bushing monitoring system. It continuously measures up to six leakage currents, tests the power factor and capacitance values and monitors the condition of bushings, CCVT`s 1) and free-standing CT`s.

The bushing monitoring system incorporates three measurement modes for standard and two for optional configurations.

Standard configuration with 6 current inputs:

• Sum of three current test
• Adjacent phase reference test
• Phase comparison

Optional configuration with 3 voltage and 3 current inputs:

• Reference test (3 bushings and 3 CCVT`s 1))

Optional configuration with 6 voltage inputs:

• CCVT 1) Reference test (6 CCVT`s 1))

The bushing sensors / adapters are connected to the capacitor taps designed for all types of bushings to allow measurement of the leakage current up to 140 mA AC.