Περί UPS

[Christos Ricudis]

Giorgos D. Pallas wrote:
> Η τεράστια έκταση αυτού του thread αποδεικνύει ότι η κατάσταση με τα UPS
> και το ρεύμα είναι γενικώς σκατένια. Στο κέντρο δικτύου του ΑΠΘ με τα
> δυο UPS τα πανάκριβα και καλοσυντηρημένα των 15 KVA έκαστο, περισσότερες
> διακοπές έχουμε εξ'αιτίας των UPS παρά εξ'αιτίας της ΔΕΗ.
>   

Pes olh thn istoria.

Prin apo arketa xronia, kapoios sth DEH apofasise oti o bereses ape8ane, 
kai aplws *ekopsan to reyma* se olo to panepisthmio gia lhksipro8esma 
xreh. Htan malista arketa kafroi wste na to kopsoun paraskeyh meshmeri.

Mexri na apokatasta8ei to reyma thn Deytera, eixan katastrafei arketa 
eyais8hta antidrasthria kai deigmata poy briskotan sta psygeia twn 
ergasthriwn ths farmakeytikhs kai tou biologikou, shmantikhs xrhmatikhs 
aksias. Etsi apofasisthke na egkatasta8ei
sto ktirio tou biologikou mia gennhtria. Epeidh twra tyxainei to IT 
support kai to Network Operations Center tou panepisthmiou
na briskontai sto ktirio tou biologikou, mporoume na zoume me thn 
pseydais8hsh oti h gennhtria mphke gia na sthrizei tis zwtikes 
ypologistikes ypodomes tou panepisthmiou, kounia pou mas kounage.

Ta xronia perasan, kai oi anagkes tou panepisthmiou se xwrous 
ayksh8hkan. Etsi mia wraia mera kapoios apofasise na kleisei th 
gennhtria me gypsosanides, gia na ftiaksei gyrw gyrw grafeia.

To teliko apotelesma, einai oti to sequence diakophs reymatos synh8ws 
paei ws ekshs :

1) Peftei to reyma.

2) Dyo apo ta tria UPS tou orofou arxizoun na dinoun kanonika reyma. To 
ena peftei.

3) Gyrw sta dekapente deyterolepta afou exoun kanei shutdown ta UPS 
epeidh tous teleiwse h mpataria, pairnei mpros h gennhtria. Ta UPS 
ksypnane kai arxizoun na fortizoun. H gennhtria dinei toso kalhs 
poiothtas reyma, pou oi mises lampes tou orofou apodhmoun eis kyrion.

4) Pente lepta argotera, h gennhtria exei mpoukwsei kai peftei. Ta UPS 
arxizoun na klaine ola mazi. 

5) Ta sbhnoume ola kai phgainoume gia kafe mexri na epanel8ei to reyma.

Parempiptontws, sto pseydopatwma katw apo to grafeio mou pernaei mia 
paroxh 3*80A. Mexri prin apo kanena xrono malista, pernouse *akribws* 
katw apo thn karekla moy. Kapoious apo aytous pou ergazotan edw apo thn 
epoxh tou Kwnstantinou Kara8eodwrh mou eipan oti prin apo merikous 
aiwnes eixan ferei ena pediometro, to metrhsan, kai to brhkan entos 
oriwn. Na tous empisteytw?

And a bit of history : Ston toixo apo pisw mou brisketai To Megalo 
Kokkino Koumpi pou Kobei to Reyma. Einai malista tyligmeno kala kala me 
seloteip gia na mhn patietai. Mou exoun pei oti einai aposyndedemeno kai 
oti exei stamathsei na kobei to reyma edw kai xronia, alla akoma ki etsi 
egw kolwnw na to aggiksw.

> Για δε συγκεκριμένα τα cisco μηχανήματα, έχουμε κάτι πανάκριβα Cisco RPS
> (redundant power switches) που βγάζουν DC ώστε αν καεί το ΑC τροφοδοτικό
> του switchακίου ή του routerακίου, να συνεχίσει να παίζει με το DC.
>   

O pragmatikos logos pou ayto yposthrizetai bebaia, einai allos :

1) To standard paroxhs reymatos sthn thlefwnia einai -48VDC. Otidhpote 
eyelpistei na to afhsoun na bidw8ei panw se ena telco rack, prepei na 
dexetai DC.

2) Sthn koinh periptwsh pou exeis ena data center me UPS, h katastash 
paei kapws etsi :

Paroxh AC ---> AC/DC conversion sto UPS ---> mpataries ---> DC/AC 
conversion sto UPS --> AC/DC conversion sto trofodotiko ths syskeyhs.

opote, se ena elegxomeno periballon, einai merikes fores kalytero na 
petakseis eksw ta redundant AC/DC kai DC/AC conversions, kai na pas apla 
apo tis mpataries katey8eian ston eksoplismo, glytwnontas thn apwleia 
energeias sth metatroph.