Sefuse thermal fuses nec schott sf226e 1 this thermal fuse uses an organic thermosensitive pellet inside a metal case features a large cutoff rated current of up to 15 a 250v ac the device contains a sliding contact springs and a thermal pellet inside a metal case when the spring is compressed firm contact between one lead and the sliding contact occurs at normal temperatures current flows from the lead to the sliding contact and then through the metal case to the other lead when