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 85A for VigiPacT monitoring and protection relays. The transmission ratio is 1/1000. The internal diameter of the toroid is 50 millimeters and the weight is 0.200 kg. The cables must be centered inside the toroid and the diameter of all these cables must not exceed 25 mm. The maximum cross-section per phase (R, S, T, N) is 50mm² for a copper conductor.