Recently, I checked all the circuit breakers in my 200 amp service Square D panel box. When I attempted shutting off the main breaker, it wouldn't budge. Does anyone know why this breaker will not shut off---is there a special trick involved? There is a rectangular piece of plastic over the breaker, maybe 5 mils thick, which appeared to scrunch up a little when I applied effort to turn the breaker off. I appreciate any information I can get regarding this issue.
