NORSTAT Safety Relays - Handbuch (Seite 79)

application guide safety relays from riese electronic page 75
4 Product application for
- two hand control relays
Impulse diagram for two hand control
relays type III (III a, III b, III c)
a)
SAFE CZ
13-14
23-24
S2
on
power
off
S1 0,5s
<-->
0,5s
<-->
0,5s
<-->
0,5s
<-->
Two-hand application type IIIC with checking of synchroneous
actuation.
Both keys consist of a n/o and a n/c switch. The first pushbutton
switches output S11 from input S22 to S12 and the second one
switches output S21 from input S12 to S22. Bridge S21-S32 is
configuring the device to work without AND combination (stand alone).
The feedback control must be closed either by a n/c contact of an
expanding relay or by a bridge between.
category 4; SIL3; PLe reachable
S32 S12 S11 S34 S21
Kext
A1 S33 S35 S36 S37 34
+24VDC
S21 S22
44
14 24
A2
0VDC
Two-hand application type IIIC with AND-combination.
The function is the same as in the 1st application, except the open
input S32 configures the device without AND-combination. It is
attached to the input S33. Allowed are the outputs 14, 24 of all family C
devices.
category 4; SIL3; PLe reachable
S32 S12 S11 S34
Kext
A1 S35 S36 S37 34
+24VDC
S21 S22
44 A2
0VDC
"UND"
S33
14 24
Two-hand application type II without monitoring of synchronous
actuation.
The function is the same as in the 1st application, except the bridge
S11-S35 configures the device for a function type II without control of
synchronous actuation. Reactivation of the safety outputs 14, 24, 34,
44 is only possible when the two push-buttons are disengaged
synchronous a new actuation.
category 3; SIL2; PLd reachable
S32 S12 S11 S34 S21
Kext
A1 S33 S36 S37 14 24
+24VDC
S21 S22
34 A2
0VDC
44
S35
Combination examples
Contact expansion over the emergency stop circles.
If the device A switches off (the outputs have low potential), the
contactors K1 and K2 will de-energise. Device B switches off its
safety outputs via its own e-stop circuits, as well, and though
contactors K3, K4 de-energize.
Up tocategory 4; SIL3; PLe reachable
S32
S33 24
S11
K1 K2 K3 K4
14
A B
24
14
safety
input
safety
input
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