A 1 0-A time-delay fuse is the maximum size permitted
to protect the 3-k VA transformer. Time-delay fuses an
used when the overcurrent device is sized at less thar
15 A. The over current device protecting the primary of the
transformer is permitted to be sized as large as 2. 5
(250%) times the primary full-load current, provided the
transformer secondary is also protected, Figure 14-25
The transformer secondary overcurrent device is sized a
1.25 (125%) times the secondary full-load current. The
next size larger overcurrent device is permitted except
where the secondary current is less than 9 A. In thi
case, the overcurrent device is not permitted to be large
than 1. 67 (167%) times the transformer secondary circuit