PABX Restarted abnormally

[mshahzadjaved]

We have an Alcatel PABX-4400(R10) with almost 1300 users(analog and digital). Two rectifier are feeding in parallel.
Yesterday, the following problem occurred.
Rectifier#01 Preventive maintenance job was in progress. After putting off the breaker of rectifier#01 the system voltage was 53VDC and rectifier#02 was in service. Almost 5mins after this activity the exchange main CPU restarted, all the operator consoles and users found dead. Almost after 30mins system again normalized.

What could be the possible reasons for this problem?

[frank]

Can you throw some logs ?

[haroun]

two rectifiers feeding in parallele strange as solution you need how much current or you mean master-slave rectifier ? and no batteries?!
53 v dc was in he pbx bornes or on the rectifier display?
site with duplcated config (cpu)?
logs ,
grounding is good?

[Klink]

Should be able to give you an analysis if I can take a look at the infocollect. Usually the incidents just before the reboot should tell you what happened. Try "incvisu -b 1" and check just before the reboot. Was there a crashdump generated?

[Klink]

Darn it. I'm posting on an outdated thread again.