HIGH ATTENUATION ISOLATION TRANSFORMERS
WITH OVERVOLTAGE PROTECTION
The models of the RS series are characterized by:
- high attenuation of common mode disturbances, achieved thanks to a groundconnected electrostatic shield inserted between the windings;
- attenuation of overvoltages caused by lightning and line commutations. This is obtained by connecting 3 varistors between phases and ground. Each surge arrester is fitted with a device signaling when the varistor is out of order.
HIGH ISOLATION AND ATTENUATION TRANSFORMERS
Thanks to their peculiar technical features and to the shielding between primary and secondary windings, these isolation transformers can stand high isolation voltages, both impulse type and at 50 Hz. Also this series is characterized by high attenuation of common mode disturbances.
CLASS II ISOLATION TRANSFORMERS
The peculiar characteristic of this series of transformers is their compliance to Standard EN 61558-1, certified by CESVIT-CETACE. Therefore these models, being classified as “class II transformers”, allow the building of plants assuring both the safety of operators and the continuity of operation of the connected transmission systems. In other words, it is possible to:
- install only a thermomagnetic circuit breaker without residual-current protection on the line fitted with double-insulation cables, connecting the “delivery point” to the isolating transformer;
- install specific surge arresters for protection against atmospheric discharges on the primary winding of the transformer. The non-use of residual-current circuit breakers avoids the untimely circuit opening due to very small leakages caused by inductive phenomena.