If you shutdown your mining rig that consists of 1000 s19 miners
how long will it take since you decide to turn them on until the hash rate is stable on the pool and running?
First, the hashrate needs to become stable locally on the miner itself, most miners go through a warm-up/tune cycle before reaching full hashrate, depending on the miner's model and firmware, this could take anywhere between 1 to 60 minutes, it depends on a lot of factors.
For the hashrate to become stable on the pool, it's a matter of luck and pool difficulty, and whether or not the miners run behind a proxy, but usually 5-10 mins, depends on the pool of course, some of them have 5m hashrate display, some have no less than 15 mins so you can only tell when 15 mins had passed, but rest assured, every share you submit counts even if the chart on the pool page doesn't catch up fast enough.
open the machines > mine 10 minutes > close all the machines
once every 1 hour
what will happen to the machines?
This will probably reduce their lifespan.
how much will it save in electricity if you shut them down completely and if you just stop mining for 50 minutes
When you shut your gears down, you save 100% of the electricity they use, but then you gain nothing, in fact, you spend more energy by doing so, the warming up, fan check and the rest will consume power for no gain in pool shares, so there is no gain at all, what are you up to anyway?