We had the same type of scheduled power outage here for an electrical
upgrade in the factory.
We brought in a generator to feed power to our UPS to keep all of the
computers running for our other sites.
The computers were the only things receiving any power. Unfortunately
we forgot about the sump pump and after about 24 hours of being off
water came into our office and was only inches from the computer racks
when it was discovered.
It was quite a circus to stop it and clean it up without power or
Our very bad mistake.