Buchholz Relay Alarm Part 4

We already see combustible gas accumulation on gas analyzer, please visit Buchholz Relay Alarm Part 3 for previous explanation. We don't want that transformer is going to be fatal accident as picture below.




The transformer itself already has signal protection as below, for example buchholz relay alarm if the gas accumulation already above 550 cu cm, the lockout relay should be active to open CB on 500kV.



Gas Accumulation Root-Caused Suspect
Transformer insulator broken.
HV and LV Bushing Duct Gasket Leak.
Oil cooler venting valve passing.
Oil cooler at negative pressure line leak.
Conservator rubber bag leak.


Transformer Test should be carried out to find out where the root caused.
Transformer insulator broken test by
Turn ratio test.*
HV & LV winding resistance test.*
Insulation resistance test.*
Insulation Power Factor and Capacitance test.*
Bushing Power Factor and Capacitance test.*

Transformer Inspection.
External and internal inspection for check Bushing duct gasket leak, oil cooler venting valve passing and oil pipe leak.
Conservator rubber bag leak by pressurized test.*

Note : * The test is carried out before oil insulating drained and purified.

Please visit Transformer test result on Buchholz Relay alarm Part 5.