Michelle Sullivan http://www.mhix.org/ Sent from my iPad
> On 03 May 2019, at 02:24, Michelle Sullivan <miche...@sorbs.net> wrote: > > N.J. Mann wrote: >> Hi, >> >> >> On Thursday, May 02, 2019 09:27:36 +1000 Michelle Sullivan >> <miche...@sorbs.net> wrote: >>>> On 02 May 2019, at 02:16, Chris <chrco...@gmail.com> wrote: >>>> >>>> Your story is so unusual I am wondering if its not fiction, I mean all >>>> sorts of power cuts where it just so happens the UPS fails every time, >>> The only “fiction” is the date.. was the 10th not the 19th March... >>> https://www.southcoastregister.com.au/story/5945663/homes-left-without-power-after-electrical-pole-destroyed-in-sanctuary-point-accident/ >>> >>> UPSes do glitch out sometimes, but rarely.. they do have problems when >>> 11kv comes down a 240v line though... >> I am sorry to hear about your loss of data, but where does the 11kV come >> from? >> I can understand 415V, i.e. two phases in contact, but the type of overhead >> lines in the pictures you reference are three phase each typically 240V to >> neutral and 415V between two phases. >> > Bottom lines on the power pole are normal 240/415 .. top lines are the 11KV > distribution network. > Oh and just so you know, it’s sorta impossible to get 415 down a 240v connection, for that to happen you’d need to disconnect any return (neutral) and then connect it to another phase... and as most connections are TNE that means dropping the cables on the incoming connection and having a really dodgy connection. It is very unusual to get 11kv down a distribution phase and pretty much the only time I have ever seen it is when a cable is cut (a 11kv line) and it falls onto a supply cable... lightning strikes are the most common case. The second most common (and they are really not) is someone taking out a pole. The system is designed to drop power out instantly when it happens which is why it is rare to do damage but we (sparkles) all know that it’s milliseconds not “instantly”. Unfortunate part of this is if they hit the power pole next up the road.. there was no 11kv distribution cables.. as you can’t see in the photos the pole on the other side of the road had a transformer (not the same one that blew the night before...) It was a classic example of Murphy’s law, (if something can go wrong to make @ bad situation worse, it will).. if it wasn’t in the middle of a resilver it would not have had this issue. If a transformer hadn’t blown on the network 6 hours before I wouldn’t have even been connected to that substation. If the transformer that blew hadn’t ZFS would have just don’t the rollback I did the night before... if I hadn’t gone to the server room and checked everything and restarted the resilver it wouldn’t have been doing anything to the drives. If the UPSes hadn’t failed on the night it would have probably been waiting for me to rollback the 5 seconds when the pole was taken out...etc...etc... So many... “if this didn’t happens it would have been ok...” > >> Best wishes, >> Nick. > > > -- > Michelle Sullivan > http://www.mhix.org/ > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org" _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
