$I^{2}t={\displaystyle \underset{t_0}{\overset{t_1}{\int }}{i}^2}\mathrm{d}t$

Note 1 to entry: The pre-arcing I²t is the I²t integral extended over the pre-arcing time of the fuse.

Note 2 to entry: The operating I²t is the I²t integral extended over the operating time of the fuse.

Note 3 to entry: The energy in joules liberated in one ohm of resistance in a circuit protected by a fuse is equal to the value of the operating I²t expressed in A² • s.