Dogtrousers
Lefty tighty. Get it righty.
Regarding back up generators for businesses: there was a lovely story about a financial services company having a power outage. Their systems instantly flipped to their battery backup without any loss of service, and a few minutes later their diesel generators fired up and it all worked perfectly ... until two days later when the gennies ran out of diesel. The person whose job it was to call out the lecci company and / or top up the diesel had been made redundant in a re-org a couple of years befor
Back in the 90s there was a test of the generators at a place I worked, which doubled up as a recovery facility for a some institution in the City.
Power outage simulated: good. UPS kicked in: good. Generators fired up: good. Exhaust from the generators entered the building and set off the fire alarms: not so good.