CTN5 current transformers are 1-phase transformers designed for external application. The secondary winding wound on the toroidal core is placed in a case. The case is filled with electro-insulating resin, which protects the device against damp and undesirable interference in the structure.
The connecting cable (2×2.5 mm2, 4 or 6 m length) has a reinforced double insulation made of rubber with limited flammability and oil-resistance. The cable is led out of the case through the gland. Current transformers are installed directly on a current circuit or set on a transformer tank. The circuit passes through the opening of the device case and is its primary winding. Two threaded holes M5 enable fixing the device in a required position. In addition, the transformers have special ribs which protect against the accumulation of water in the opening of the current transformer case when it is placed on a flat surface.