Carpenter ants pose no harm to humans since they do not carry any diseases that you can get infected with should the carpenter ant bite you.
But you may feel some pain from the bite when a carpenter ant bites you but nothing else should happen except maybe a rash unless you're allergic somehow to the carpenter ant.
Carpenter ants mostly pose a danger to structures made of wood since the carpenter ant eats through wood and can cause serious major and costly damage to a home should they be allowed to stay around.
That's why you need to get rid of carpenter ants when you notice them because they can destroy your home.