Description of the individual safety relays
3.7 3TK28 safety relays with solid-state enabling circuits
3TK28 safety relays
Manual, 07/2016, NEB926157502000/RS-AB/003
129
3.7.3.5
Display of the operating state
The operating state and functioning of the device are indicated by three LEDs:
●
POWER
●
RUN
●
FAULT
Operating states of 3TK2842
= 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
3)
Pressed
Not pressed
On / 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"
3)
Delay time running