Switching control for emergency current supply - has relays in each control element ensuring switching in voltage-free condition

摘要

The switching control has a control element (4) for switching between the mains current supply and the emergency current supply using phase monitoring relays providing delayed switching in a voltage-free condition. Pref. a respective control element (4) is used for each distribution circuit, with a remote-control linked to the emergency current supply (3) allowing the operation of the control elements (4) to be tested. ADVANTAGES - Prevents contact melting by arcing.