How we savved a Generat G tor (in fact f tw wo), agaain! Backgrround
I
t was just anotheer day and d another morning of o January 2019, on which wee received a call from m a new Customer C in Metal Seector, from m Chhattissgarh. And d urgently, they t wanteed us to teest and com mmission an old 10 M MW, 11 kV Generatorr along with h its relayin ng, schemees and com mplete testing. On enquirring about such urgeency, we le earnt that their origiinal Generator rated d 12 MW, 11 1 kV got burnt (staator) and was w sent for f repairin ng, this 10 0 MW wass taken on rental basis and a temporaryy solution. As we aall know th hat in ourr industry, Generatorr failure is nothing le ess than an a air‐crash and thiss criticalityy warranted d extensivve and meethodical analysis a like an air‐‐crash inve estigation.. Hearing th his, the daay went intto a tizzy and a we im mmediatelyy started preparing a checklist (we’ll ( see it later in a diagram)) to find out the Roo ot Cause. And A unlesss we find th he Root Cause and so olve it, this rented Geenerator w was in danger and thee too! upcomingg repaired Generator G We immediately dispatched 2 of our enggineers alo ong with th he test setss required,, by the firsst flight avaailable and d were soo on on the jo ob. In less than a dayy, we weree up and wo orking.
Findinggs‐ at Site ‐
The initiall forensics were found from th he fault reecords of tthe Relay. We learntt that the Relay R (and d GCB eventually) was w tripped d on NPS protection n, which iss normally a time delayed prottection. It was a surprise, becaause norm mally when n such faultt occurs (sttator failurre), other protection ns take carre, NPS is something s g like last lin ne of defen nse.
‐
So, such a surprisingg observattion just att the start of the job b prompted us to bee extra vigilant. This warranted d us for in‐depth and thorou ugh checkiing of thee protection n system.
d Channel Partners Authorised