The maximum size over current device is 65 A. Checking
a fuse catalog or NEC Section 240-6, 65 A is not a standard size. However, Exception No. 1 to NEC Section
450-J(b)(l) permits the next higher standard size over current
device to be chosen. Therefore, the maximum
size over current device permitted for this situation is
70 A. A smaller size over current device could have been
used; for example, 60 A. In fact, the over current device
can be as small as desired as long as it is large enough to
satisfy the load requirements.