is your breaker seprate from your main breaker ? or tap on to your main breaker ?
cos if your purpose is to prevent any stuff tripping your tank... your tank breaker should be seprate from your main breaker.. which means your house will have 2 breaker.. one for your tank and the other for your house. this way if your house trip, your tank will still have electrity.
if not your house breaker trip, your tank will follow.