This toroid is designed for Vigilohm insulation fault locators and VigiPacT type A residual current protection and monitoring relays. It allows monitoring the fed component of Vigilohm Insulation Monitor and measuring a nominal current up to 160A for VigiPacT monitoring and protection relays. The transmission ratio is 1/1000. The inner diameter of the toroid is 80 millimeters and the weight is 0.9 kg. The cables must be centered inside the toroid and the diameter of all these cables must not exceed 40 mm. The maximum cross-section per phase (R, S, T, N) is 95mm² for a copper conductor.