Situation is: A residential home with a detached garage has a sub panel which is serviced from a 50A breaker located in the main breaker box. This service feed is approximately 20'. The house has a meter pan/disconnect where the 200A service enters the house. The breaker box is approximately 30' from the meter pan. There is a grounding rod, earthed at the meter pan entrance which goes to the breaker panel. The water lines are bonded. My main question is should the sub panel in the garage be earthed or do I use the ground wire from the main to act as my safety ground like to carry currents from a lightning strike to the original earthed point all the way across the house by the meter pan.
Since the garage is detached, wouldn't I want to provide a path for lightning to the closest point?
Any advice will be appreciated. :-) Thank you