What is the difference between them?
If I connect network infrastructure directly to a power feed A, and behind that is a diesel generator for backup power. Does a diesel generator work instantaneously, so there is in effect "no break"?
In such a setup, is a UPS even needed?
I read that typically a UPS works only for a short time, so that you have enough time to power down critical infrastructure correctly. Is that the main purpose of a UPS? To run for just such a short time?
Or does it also handle peaks in current?
Or is a UPS needed for a short time, so that a diesel generator can kick in?
In case there is a power outage it sometimes takes a couple hours to fix, will a diesel generator (in general) provide enough power to mitigate this?
What is the best setup? Is it network infra power supply A, then UPS, then UPS plugs into power feed A, and power feed A is backed up by a diesel generator? And then for B as well?
