I
Electric Current
The flow of electric charge, measured in amperes.
Key symbols
Ib = design current of the circuit. In = nominal rating of the protective device. Iz = current-carrying capacity of the cable in its installed conditions. It = tabulated rating.
Golden rule
For overload protection: Ib ≤ In ≤ Iz, and I2 ≤ 1.45 × Iz (Reg 433.1.1).
Key regulations
433.1.1Appendix 4