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Description of the individual safety relays
3.2 Overview
3TK28 safety relays
14
Manual, 07/2016, NEB926157502000/RS-AB/003
3.2
Overview
Overview of 3TK28 safety relays
The following tables provide an overview of the 3TK28 safety relays.
3TK28 safety relays with relay enabling circuits
3TK28..
20
21
22
23
24
25
27
28
30
34
SENSORS
Electromechanical
X
X
X
X
X
X
X
X
-
X
Solid-state
-
-
-
-
-
-
-
-
-
-
Magnetically-operated switches
X
-
-
-
-
-
-
-
-
-
START TYPE
Auto
X
X
X
-
X
X
-
X
-
-
Monitored
X
X
-
X
X
X
X
-
-
-
ENABLING CIRCUITS
Instantaneous
3 NO
3 NO
2 NO
2 NO 2 NO
3 NO
2 NO
2 NO 4 NO 2 NO +
2 NC
Delayed
-
-
-
-
-
-
2 NO 2 NO
-
-
SIGNALING CIRCUITS
Relay
1 NC
1 NC
-
-
-
2 NC
1 NC
1 NC
-
2 NC
Solid-state
-
-
-
-
-
-
-
-
-
-
Max. achievable SIL acc. to
IEC 61508 / IEC 62061
3
2
3
3
2
3
3 / 2
(tv)
3 / 2
(tv)
as BU
3
Max. achievable PL acc. to
EN ISO 13849-1
e
d
e
e
d
e
e / d
(tv)
e / d
(tv)
as BU
e