Electrical outlet is 30 volts LOW or HIGH sometimes?

The preacher (Kelly) from church is in a 3rd world country. They have electricity for a few hours 2 times every day. When the electricity comes on it is always LOW or HIGH for about 5 minutes before it becomes stable at 120 VAC.

Kelly knows about electrical and mechanical stuff we worked together for 6 years before he became a preacher. Kelly has rigged up a transformer with multiple taps so if the voltage is 30 volts too high or 40 volts too low he can flip a selector switch to get 120 VAC while they wait for the voltage to stabilize.

Kelly wants to know if there is a way to use a time relay to keep everything off for 5 minutes while the voltage stabilizes. I told Kelly to use a 5 minute Potter and Brumfield time relay to turn on a 100 amp motor starter.

Kelly can order the things he needs on Ebay and have them mailed to him.

One thing I don't know is, what will the timer relay do if it is trying to start on 70 volts or 150 volts AC?

I am open for suggestions???

If you know what TDR you want him to buy, read its spec sheet. You'll find the max and min operating voltage in there.
If you can't find a suitable TDR, make a crude DC supply (zener?) and feed it into a DC TDR. A zener supply should have enough lattitude to handle big swings.