32
SI-Safety Installation & Operating Manual
Issue Number: 1
The drive SAFE TORQUE OFF meets the requirements of the following standards, for
the prevention of operation of the motor.
•
EN 61800-5-2:2007 SIL 3 (PFH
≤
10
-8
)
•
EN ISO 13849-1:2006 PL e (MTTFD >10
5
yr)
3.3.3
Two channel switching output with external monitoring
For safety applications for cat 3, PLd in accordance with EN ISO 13849-1:2006, it is
required to engage two complementary outputs as a group, thereby activating for
example, two external power contactors.
Figure 3-16 Two channel switching output with external monitoring on input E0.5
as combined feedback
The two external monitoring contacts which are switched in series, receive power from
clock signal P1 and are scanned via input 1. Input 1 is used as the read back input, but
this function can also be assigned to a different input.
It is important to note that a single short-circuit from the SAFE TORQUE OFF input to a
DC supply of approxi24 V would cause the drive to be enabled. This can be
excluded under EN ISO 13849-2 by the use of protected wiring. The wiring can be
protected by providing the wiring with a grounded shield in a positive-logic grounded
control circuit. The shield is provided to avoid a hazard from an electrical fault. It may be
grounded by any convenient method; no special EMC precautions are required.
If the use of protected wiring is not acceptable, so that the possibility of this short circuit
occurring is anticipated, then a relay must be used to monitor the state of the SAFE
TORQUE OFF input, together with a single safety contactor to prevent operation of the
motor after a fault.
WARNING
The SI-Safety module STO output is designed to be connected directly to the drive SAFE
TORQUE OFF input (terminal 31). This output must be used correctly to prevent the
machine from being driven if the module detects a fault.
NOTE
I/O interface
SBC1
SBC2
STO
E0.5
P1
P2
Содержание unidrive m
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