yesterday i wired up a wet switch to a rheem system in an attic. the wiring was a pack rats nest and i wraped my common into a nest of common wires under a nut. i should have taken the time to untwist the nest and properly lay each wire next to each other and assure a good conection. to contine my story---- the wet switch had the green light lit. so i assumed all was well. well the stat din,t have any digital numbers in display. so i went bach in attic and checked my hots all was well and wet switch was red. on the way down the rickety on ladder the bottom two step broke. my day was going to hell tooo much time in the calll . so i take the stat off the wall plate and check voltage between red and common 21 volts. so i suspect the stat is bad. i put stat on wallplate and display is there. i then switch to cooling and it disappears. lady says she has had stat troubles before so i really think its stat. so i beging to fix ladder and call senior tech ... buddy. he is on way while i fix ladder. my happy fri has gone to hell. well i get some metal out o truck and screws and repair ladder before he gets there. he goes up and finds common going to stat not tighty under wire nut. he then redoes common connection under nut i measure voltage at stat its 29 volts and all is fine.
so lesson here--- time is money bu,t you must take enough to fix rats nest of wires under nut. i keep looking at lit green on wet switch and 21 volts at stat wall plate and could only think bad stat.
so here is the question what is the min voltage to look for in order for a stat and other components such as contactor of relay to work? its not 21 hehehehe