Siemens 4MS4 outdoor voltage transformer double-phase small

Siemens 4MS4 outdoor voltage transformer double-phase small,
Voltage transformers have only one magnet core, and are
normally designed with one single secondary winding. If
necessary, earthed (single-phase) voltage transformers
are equippe with an additional residual voltage winding
(earth-fault winding) beside the secondary winding
(measuring winding).
In contrast to current transformers, voltage transformers
must never be short-circuite on the secondary side. The
earth-side terminal of the primary winding is effectively
earthed in the terminal box, and must not be removed
during operation.