Some times these changes take years before they are recognized as being problematic, and thus reduce our ability to recognize trouble in a transformer. A data base of dissolved gas testing results would allow for the recognition of these tendencies easily and quickly, because it allows certain trends to become obvious, which are not easily perceptible when the information is viewed in an isolated way. Once this information is available, we can act accordingly. Having an information system in place would be advantageous to the industrial user. The insulation is at the origin of the majority of the transformer defaults.
Tracking allows for the detection of faults well ahead of the protection relays reaction.
When the protection relays react, the damages are generally important and of an irreversible nature. Carry out a complete verification of the protection system once every 5 to 10 years according to the operating conditions and the immediate environment of the transformer. Specify a NLTC with an overload capacity of 125 per cent. The maintenance system should be adapted to the market reality. It would be advantageous to put in place an information system on the analysis of different results from dissolved gas analysis which could be made available to the industrial user.