I try to help my friend to hook up a new circuit breaker for his dryer. His main circuit panel has 2 empty slots (K/N) and the recent electrician left the label "Do Not Remove these K/N". Is it OK to use this slots ? and why the electrician placed that label there ? if it's not OK then could I add a sub-panel and how many Amp?
Turn off MAIN Breaker and remember there is still HOT wires feeding the main Breaker Take cover off and inspect to see if you have busbar there what the breakers hook to.The only time I put Do Not Remove these K/N on the cover is when threre is no busbar for the breaker to hook to. Or the main is sideways and you will see the back of the breaker.