Protection current transformer 400/5 A
Protection current transformer for protection relays · ratio 400:5
7 CELSA protection current transformers with a ratio of 400/5 A: Protective current transformer (IB-50, IBG-50, IBR-1 …). Accuracy class 5P5–10P10, rated burden 1.25–5 VA, window for round conductors Ø 23–80 mm. From €54.62 incl. VAT, with datasheet, direct from the manufacturer.
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Frequently asked questions
What does 5P10 mean?
Protection CTs transmit even high overcurrents faithfully so that protection relays trip reliably. In 5P10, "5P" means a composite error of at most 5 %, "10" is the accuracy limit factor: the limit holds up to 10 times the rated current. Available here for 400/5 A: 5P5, 5P10, 10P5 and 10P10. Protection CTs explained →
What does 400/5 A mean?
With 400 A in the primary conductor, the transformer delivers 5 A to the meter or measuring device – a ratio of 80:1. Meters and instruments are set to this CT ratio.
Will it fit my cable?
The window decides: the types listed here take round conductors of Ø 23–80 mm, depending on the type. The datasheet of each type gives the exact window and busbar dimensions. CT finder →













