Positively Driven Contact Elements/Mirror Contacts - Siemens SIRIUS 3RT Series System Manual

2.1.3

Positively driven contact elements/Mirror contacts

Up until a few years ago, just one standard term, "positively driven contacts", existed for
contactors. This term was not clearly defined until the year 2000 in standard EN 60947-1 and
it applied to all contactor relays and power contactors.
Positively driven contact elements for contactor relays acc. to EN 60947-5-1, Annex L
According to EN 60947-5-1:1997+A12: 1999+A1:1999+A2:2000, Annnex L, positively driven
contact elements are a combination of "n" NO contacts and "m" NC contacts, which are
designed such that they cannot be closed simultaneously. "Positively driven operation" may
only apply to auxiliary switch elements which are contained in switching devices and whose
actuating forces are generated internally. An example of such elements are the SIRIUS
3RH2 contactor relays.
All SIRIUS 3RH2 contactor relays (with at least 1 NC contact) are tested to EN 60947-5-1
and have featured positively driven contact elements in the basic device or in the basic
device in conjunction with auxiliary switches ever since the product was launched.
Figure 2-1
Mirror contact for power contactors in accordance with EN 60947-4-1, Annex F
According to EN 60947-4-1:2001+A1:2002+A2:2005, Annex F, a mirror contact is an
auxiliary NC contact that cannot be closed simultaneously with a main NO contact.
Figure 2-2
All SIRIUS 3RT2 motor contactors (with at least 1 NC contact) are tested to EN 60947-4-1
and have featured mirror contact characteristics in conjunction with auxiliary switches ever
since the product was launched.
Note
Both contact characteristics, the positively driven contact element in the contactor relay as
well as the mirror contact in the power contactor, meet the same technical requirements.
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
Symbol for positively driven contact elements in a switching device
Symbol for mirror contacts in a switching device
SIRIUS 3RT2 contactors/contactor assemblies
2.1 Standards
103