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Safe Torque Off
6-29
890CS Common Bus Supply - Frames B & D; 890CD Common Bus Drive and 890SD Standalone Drive - Frames E & F
SS1 Implementation using Safety Control Unit
This Safe Stop 1 (SS1) implementation causes the drive to come to rest in a controlled manner, and STO is
actioned after a time delay determined by the safety delay relay. This conforms to SS1 defined in EN61800-5-
2:2007 para 4.2.2.3 c). The example shows wiring and terminal numbering for a Siemens 3TK2827, but similar
products are available from other vendors. The user must select and assess appropriate equipment.
Note: On power-up, the Safety Control Unit outputs are OPEN; thus STO is requested of the 890. This responds
by energising KA1 if both channels are active and healthy. KA1 is used as a self-check for the reset cycle of the
Safety Control Unit. If a reset cannot be achieved due to KA1 being de-energised, a fault may be present and
must be resolved by the user before relying on the STO function. See Fault Operation on page 6-16.
Note 1: Refer to manufacturers instructions for wiring and earthing detail.
X11/01
X11/02
X14/04
DRIVE START
DRIVE STOP
890 STO
RESET KA1
SAFETY
DEMAND
KA1
POWER
SUPPLY
*Note 1
THIS WIRING MUST BE WITHIN THE CONTROL CUBICLE.
24VDC
SAFETY CONTROL UNIT
A1
Y12
Y11
A2
PE
Y33
14
48
58
Y21 Y22
47
57
Y10
13
Y34
X15/02 X15/03
X11/03 X11/06
X11/03
X11/04 X11/05
0V