Description of the individual safety relays
3.7 3TK28 safety relays with solid-state enabling circuits
3TK28 safety relays
120
Manual, 07/2016, NEB926157502000/RS-AB/003
3.7.2.5
Display of the operating state
The operating state and functioning of the device are indicated by three LEDs:
●
POWER
●
RUN
●
FAULT
Operating states of 3TK2841
= off
= on
= flashing
LED
Operation
POWER
RUN
FAULT
Line supply
EMERGENCY
STOP
ON
Outputs
On
Not pressed
Pressed
On
Pressed
1)
Not pressed
Off
Not pressed
Not pressed
Off
Self-test on startup approx. 7 s
Fault
•
Fault in electronics
•
Change of pin assignment during operation
•
Short-circuit to 24 V
2)
Off
Supply voltage missing
1)
Sensor circuits open; cross-circuit between sensors; short-circuit of sensors to ground.
2)
Only on circuit variant with "cross-circuit detection"
