when checking a home circut what value should you get showing on a multi meter? i am getting a reading of 243 and 123 on the two circuts i am checking. i am hooking up a pool pump and the circut reads 243 so should i switch the internal switch to 230? i tried this before and the pump ran for a day the stopped and just hums. i have a new pump and want to make sure i get it right this time.