"wait long enough.....
Those who want to make money out of power quality will often wait for something to occur, and then focus on a single event as a means to justify their charges. In situations like this, I usually do the case pro-bono just on the off-chance the event was a solitary one. If there is a pattern, then the situation changes dramatically.
Of course, the whole lot changes if an event occurs at or about a time it was expected! In one such case a nuisance trip occurred at the prescribed time, this based on simple history of such trips. The strange part was it was blamed on a random switching event. Although there is too little data to confirm this was just a random event, it appears there are 'random switching events' occurring at the same time each and every week!
In the opening lines of this book we stated that one should be extremely wary of the person who claims to be a "power quality expert". The subject of Power Quality is a dynamic one (always changing) making it impossible to become an expert. However, there is no reason why all who are seriously contributing to Power Quality Engineering could not refer to themselves as 'specialists' i.e. those who specialise in the subject.
One thing specialists will say is "don't rule anything out", but in the same breath will also say "be careful not to over-analyse". By this they mean to not place undue emphasis on readings or events that may have been captured while doing a survey or investigation.
The caption at the top of this page is a clear example of what is being referred to. Obviously if it was a cataclysmic failure, then the failure needs to be fully dissected to ascertain the fault and reasons behind it. But all to often one may well find oneself chasing red herrings because an unexplained event was captured - you cannot win a competition by playing on the wrong dartboard!
There is also the other danger and that is to want to show that something is being done. All too often an overeager individual can land up causing more of a problem by applying a solution, than if it was left alone. The golden rule here is...
IF IT AIN'T BROKE, DON'T FIX IT!