[c-nsp] Multiple power supply failures. Advise needed

[Michael Ulitskiy]

Hello,

We have a very strange problem. We have recently changed colo-space provider and since that 
we had 4 power supply failures in all kind of cisco equipment within 2 month period.
According to colo provider we're receiving "clean" power backed up by UPSes and generator.
We're currently have 4 20-amps circuits with APC managed PDUs in them and power supply failures 
happened in 3 of them, so I can't blame it to one specific circuit or PDU.
There was no environmental warning in the logs of any cisco devices. 
I'm completely out of the clues. I'm going to bring it up with our colo-space provider, but I'm afraid
they'll need some proof or pointers.
Does anybody have any ideas what could be causing this and how I can monitor the specific conditions?
Thanks,

Michael