If a newly installed and energized transformer survives the first ten cycles, then the first ten seconds, then the first ten minutes, chances are pretty good that it will also survive the first ten years. However, manufacturers offer a warranty period for a reason. New transformers may have defects that can lead to failure. Frequently, such defects will leave their signature of dissolved gases in the oil. A timely DGA may catch the fault as it begins, before it advances far enough to do permanent damage.
Manufacturers often recommend that you run a specific initial schedule of oil tests, usually including dissolved gas analysis, on a newly installed transformer. The schedule of tests during the first month in service, sometimes longer, is so critical that the manufacturer may require specific testing in order for the warranty to continue to be valid.
Even if the manufacturer does not have a specific set of recommendations for this testing, early tests, particularly those during the first thirty days, could potentially indicate incipient faults in a timely fashion so that eventual damage to the unit, consequential damages to the rest of the system, and lost production caused by that damage can be minimized. Even though the manufacturer may be responsible to pay for repairs or to replace a failed unit under warranty, a much better solution in everyone’s best interest will result whenever you can identify a fault before it leads to failure.
