Another Tier Four Data Center with Weather Problems

[jeremysterling]

In pic 1 you see the arc damage to the 4/0 conductor and 2" bushing. Dissassembly revealed the plastic insert to the bushing was missing.

Steady rain found two small holes in the roof membrane above this 480V 600A I-line panel. Water coursed through this panel, thoroughly soaking panel, conductors, bus and breakers.

When the 225A breaker (ckt 7,9,11) tripped, operators (carelessly, IMO,) reset it. Soon after, water was noticed, and the feeder breaker to this panel was opened and locked. All the breakers in the I-line panel feed dry type transformers on the roof.

The roof top transformers (2@ 75kVA and 2@112kVA) do have rain shields. Interestingly, there is no lightning protection for the XFMR's, nor for the roof top secondary heat exchangers of the CRAC's. There is no lightning protection at all.

To restore power to the compromised feeder, we cut in a splice box above the panel. 8' of 2" FMC and 12' of 4/0 per phase and polaris blocks covered it. (The roofers had come and gone, so a N1 screw cover box was installed). Four new breakers were installed (the original six discarded).

A hypothesis was floated that lightning caused the fault, but that seems like a good excuse to get somebody to OK installing (badly needed) lightning protection. (Sorry, no pics of rooftop)

I searched the archives and found a single thread on roof top mounted XFMR's and the discussion centered mainly on corrosion. The XFMR's were filthy, but other wise OK. I did not see any bird nests, but I think additional screening should be installed.

Is lightning protection a consideration for this type of install?

Is fungicide available for these outdoor transformers?

Should there be an outage to clean and fungicide the XFMR's?

Thanks to all,

Jeremy

 

[masterinbama]

The first pic looks like as you said the insert was missing from the bushing. When these come out the bushing is left with a very sharp edge. That by itself would have caused the short. As for the water coming in. Looking at the last pic the grounds on the far left have all been duct sealed. That tells me there was some sort of wicking problem existing unless you put it there after the fact.

 

[dbuckley]

I'm surprised a "tier 4" DC would have trannies on the roof, and not inside, particularly as the trannies mentioned are quite small as these things go... To keep a data centre running you need to be absolutely paranoid about everything.