Description of the individual safety relays
3.2 Overview
3TK28 safety relays
Manual, 07/2016, NEB926157502000/RS-AB/003
15
3TK28 safety relays with solid-state enabling circuits
3TK28..
40
41
42
SENSORS
Electromechanical
X
X
X
Solid-state
-
X
X
Magnetically-operated switches
X
X
X
START TYPE
Auto
X
X
X
Monitored
X
X
X
ENABLING CIRCUITS
Instantaneous
2
2
1
Delayed
-
-
1
SIGNALING CIRCUITS
Relay
-
-
-
Solid-state
-
-
-
Max. achievable SIL acc. to
IEC 61508 / IEC 62061
2
3
3
Max. achievable PL acc. to
EN ISO 13849-1
d
e
e
3TK28 safety relays with contactor relay enabling circuits
3TK28..
05
06
50
51
52
53
56
57
SENSORS
Electromechanical
X
X
X
X
X
X
-
-
Solid-state
-
-
-
-
-
X
-
-
Magnetically-operated switches
-
-
X
X
X
X
-
-
START TYPE
Auto
-
X
X
X
X
X
-
-
Monitored
-
-
X
X
X
X
-
-
ENABLING CIRCUITS
Instantaneous
5 NO
5 NO
3 NO
2 NO
6 NO
3 NO+1 SS 6 NO+1 SS
1 SS
Delayed
-
-
-
-
-
-
-
3 NO
SIGNALING CIRCUITS
Relay
1 NC
1 NC
-
1 NC
1 NC
-
1 NC
-
Solid-state
-
-
-
-
-
-
-
-
Max. achievable SIL acc. to
IEC 61508 / IEC 62061
3
3
2
2
2
3
as BU
as BU
Max. achievable PL acc. to
EN ISO 13849-1
e
e
d
d
d
e
as BU
as BU
NO = normally-open; SS = solid-state; NC = normally-closed; as BU = as basic unit