Transient voltages occur on the terminals of superconducting coils and may lead to internal over-voltages. The main objective of this work was to calculate the transient electrical behaviour and internal voltage distribution within the ITER poloidal field (PF) coils at four scenarios and was made using the PF 3 and PF 6 coils as examples. The calculated maximum voltages will be used for definition of amplitudes and voltage waveforms for the tests of the high-voltage insulation of the coils.