Siemens 3TK28 - Display of the Operating State

Description of the individual safety relays
3.8 3TK28 safety relays with contactor relay enabling circuits
3TK28 safety relays
174 Manual, 07/2016, NEB926157502000/RS-AB/003
3.8.4.5
Display of the operating state
The operating state and functioning of the device are indicated by three LEDs:
● POWER
● RUN
● FAULT
Operating state of 3TK2856/57
= off
= on
= flashing
LED
Operation
POWER RUN FAULT EMERGENCY
STOP
Op. switching Contactors Output 2 Cause
Self-test on startup approx. 7 s
Closed
Closed
On
On
Normal operation
Open
Off
Contactors off
Open Off Open
EMERGENCY
STOP
For 3TK2857 only
Open
-
On
Off
Time elapsed
Fault
• Fault in electronics
• Contactor welded
Off -
Supply voltage missing