Siemens 3TK28 - Display of the Operating State

Description of the individual safety relays
3.6 3TK28 safety relays with relay enabling circuits
3TK28 safety relays
Manual, 07/2016, NEB926157502000/RS-AB/003
105
3.6.9.5
Display of the operating state
The operating state and functioning of the device are indicated by five LEDs:
● POWER
● S 1 ON
● S 2 ON
● CHANNEL 1
● CHANNEL 2
Operating states of 3TK2834
= off
= on
LED
Operation
POWER
S 1 ON
S 2 ON
Channel 1
Channel 2
Button
Not pressed
Only S1 pressed
Only S2 pressed
S1 and S2 pressed
The device cannot start with the following faults:
● Short-circuit, e.g. between the buttons
● Defective relay coils
● Wire break
● Jammed contacts
The output relays do not pick up if
● simultaneity (< 0.5 s) is not achieved
● only one button is pressed
● feedback circuit Y11, Y12 is open.