Off-Delay Without Control Signal - Siemens SIRIUS 3RT2 Manual

5.2.3

OFF-delay without control signal

Contacts
3RA2815 function modules switch time-delayed auxiliary contacts. They are available with
the following contacts:
3RA2815-.AW10:
3RA2815-.FW10:
Time ranges
The function modules support time-delayed switching from 0.05 to 100 s.
Function charts
3RA2815-.AW10
3RA2815-.FW10
Method of operation
When the voltage is connected to A1/A2 (contactor), the solid-state time-delay auxiliary
switch (3RA2815) switches the output relay. The operating time t starts when the voltage is
disconnected. The relay switches back to the idle state at the end of the operating time t.
There is an assurance that if the minimum ON duration is not observed either the time lapse
will not start or, if the time lapse has started, it will always be completed in an orderly
fashion. Users can rely on intermediate states of the functional sequence, such as "no relay
dropout", being detected. The minimum ON duration of 200 ms must be observed.
SIRIUS 3RA28 function modules for mounting on 3RT2 contactors
Manual, 02/2019, A5E03656507620A/RS-AD/005
5.2 Time-delayed switching of contactors
1 CO contact
1 NC contact and 1 NO contact
Functions
31