TWB SA manufactures all types of low voltage instrument transformers, current and voltage, 0.75kV and 1 kV, for indoor as well as for outdoor applications, according to IEC 61869-1. They are window, wound or split core type. They are either encapsulated by a high grade flame self-extinguishing polycarbonate housing or resin impregnated.
Highest voltage for equipment (kV) 0,72
Rated insulation level (kV) 0.72/3/-
Rated primary current (A) 150 ip to 400
Rated secondary current (A) 5 or 1
Overcurrent factor 1,2
Accuracy class 0.5S:0.5;1;3
Instrument security factor 5 or 10
Rated burden (VA) 5 up to 30
Rated frequency (Hz) 50:60
Rated thermal short-time current (kA) Ith = 60 x In
Rated dynamic current (kA) Idyn ■ 2 5x Ith
Class of insulation E
Maximum altitude of installation (m) ip to 1000
Ambient temperatire HI) - 5 up to + 50
Weight (kg) 1.10 up to 125
Specifications IEC 61869-1 & 2