Data centre power failure, temporary UPS only last 30 minutes!

We have, as it turns out (or so far we believe) a faulty 2500amp ACB. That's what I call, a problem on a live datacentre...

So a bit of a story here for the unexpected amount of views and comments, sorry I cannot answer them one by one. First of all we are not trained as LV AP on this site, so suggestions like what we should replace to what is beyond our limits, besides this ACB was unique on site with no spares. You must take into account we are temporary on the site with no one ever telling us anything, no circuit diagrams, no technical support, and basically no one knowing the site propery. However we knew from experience what was going on here, an integral protection circuit I believe was faulty, triggering tripping - unimportant exactly what, we do not take these apart and this is a known issue with these type of switchgear and it has been sent away for repair beforehand, apparently done.

Now for all those commenting on UPS, since having a known problem with the switchgear attended to by all sorts of specialists, we did have extra mobile UPS backup hence the 30 minutes we got, otherwise it would be less.

Generators were not supposed to be on - this is a bit more complex than just a power outage which we did not have, the grid was OK, this is an incomer switchgear failure. So lets say we had 2 HV-LV transformers on the same HV supply and generators are triggered by the originally built TX1 fail only. TX2 has no separate generator set, it rather bus couples to TX1 which has. Obviously if there was a HV outage, both TX would go down so that covers TX2 as well, kicking in the generators and auto bus coupling. Now since only TX2 was disconnected and only on the LV side, that does not call for a generator but does automatically try to reinstate the ACB in question, or if that fails a given number of times then bus couple over to TX1 supply which is the only generator backed supply. Now the automatic feature did not work I believe because we did have HV income, so what we done after trying to reset is to turn the incomer off, isolate it, and manually bus couple to the alternative supply wich in turn is generator backed directly.

The gear is left like that to this day after 6 months, just bus coupled to another transformer not even isolating its own transformers HV side just idling there without load. This is what happens when the owner of a property goes to the lowest bidder FM company instead of keeping one in place with the so crucial wealth of site knowledge.