Siemens 3RP25 Manual page 61

Operation options of the time relay
Operation 1
Control signal B1 is open when supply voltage A1 is applied.
The supply voltage is applied to A1/A2 and there is no control signal on B1. This starts the
star-delta (wye-delta) (ΥΔ) time. The idling time (coasting time) is started by applying a
control signal to B1. When the set time (30 ... 600 s) has elapsed, the output relays (17/38
and 17/28) are reset. If the control signal on B1 is switched off (minimum OFF period
270 ms), a new timing is started.
Remarks:
Observe response time (dead period) of 400 ms on energizing the supply voltage until
contacts 17/18 and 17/38 close.
Operation 2
Control signal B1 is closed when supply voltage A1 is applied.
If the control signal is already present at B1 when the supply voltage is applied to A1, no
timing takes place. The timing is only started when the control signal at B1 is switched off.
3RP25 Time Relays
Manual, 09/2019, A5E31947765002A/RS-AC/003
6.7 Star-delta (wye-delta) function with coasting time (idling)
Single function devices
61