This toroid is dedicated to Vigilohm Insulation Fault locators, and to VigiPacT type A residual current protection and monitoring relays. It allows the monitoring of the injected component from Vigilohm Insulation Monitor, and the measurement of a current rating up to 250A for VigiPacT monitoring and protection relays. The transformer ratio is 1/1000. The inner diameter of the toroid is 120 millimeters and the weight is 0.450kg. The cables must be centered within the toroid and the diameter represented by all these cables should not exceed 60 millimeters. The maximum cross section per phase (R, S, T, N) is 240mm² for a copper conductor.