First of all, unless you are a professional, don't attempt to change a 200 amp breaker yourself. No question about it. Could be s list of things like s previous reply mentioned. But in your situation with your experience , not trying to sound condescending, but 200 amps is nothing to take lightly. In a residential setting 200amps should be sufficient. However if your running ALot, and I mean ALOT of appliances you could need to upgrade your service. If your homes amp draw is more than 200 the main breaker will trip like any other breaker. In reality your only recommended to use about 80% of the amp rating. Again....200 Amp breaker....not a job for a do it your selfer. In this situation better to pay a professional than pay with your life.