Due to their design, an opening failure of forcibly guided contacts can be reliably detected. Relays with such contacts have the following additional characteristics compared to relays with conventional contacts: forcibly guided NC and NO contacts are designed in such a way that they cannot be closed at the same time; if a contact of a forcibly guided contact set is welded, the complementary contacts cannot close; and the contact gap must be >0.5 mm. The contacts are located in contact chambers, making them specially protected against other contacts and against the coil. Due to these normative requirements, the design and manufacturing effort for relays with positively driven contacts is much higher.