Assume that in our case, for instance, the rated current of the
GFPD (fuse) is 1A, there are 5 parallel strings in the PV array
(n=5), and I
sc of each module is 5A. Simple calculation by the
equations above will give us I
g
=25A in the worst case. According
to the melting time vs. current diagram in Fig. 4 (next page), the
1A fuse takes less than 0.01s to clear the ground fault. In this
instance, the fault path is detected by the fuse and the fault is
interrupted successfully.