... With DC immunity upon IEC 62053-21 standard Precise Current Transformer Current Transformer NRC07 CharacteristicsValuesOperating frequency50/60HzOperating temperature-25 ~ ... I max /Burden resistor Rb5Ω, 10Ω, 20ΩAccurate operating current range5% I p ~ I maxAccuracy class 0.2% ... by 3000V for 1 min.Insulation resistance> 50MΩ(CT, Current transformer, Meter components, DC immunity CT, DC immune CT ...