Functional Safety Concept; Notes; Abbreviations And Conventions; Functional Description - Danfoss VLT ISD 510 Design Manual

System Overview
•
If the SAB is only supplied with mains power,
then only the SAB control unit is running and
2 2 power is not passed on to the connected servo
drives.
Procedure for switching on the ISD 510 servo system
1. Switch U
to the SAB and servo drives.
2. Switch the mains on.
3. Set the SAB to state Operation Enabled.
4. The SAB and servo drives are now ready for
operation.

2.7 Functional Safety Concept

2.7.1 Notes

Use of the STO function requires that all provisions for
safety, including relevant laws, regulations, and guidelines,
are satisfied.
The integrated STO function complies with the following
standards:
•
EN 60204-1: 2006 Stop Category 0 – uncontrolled
stop
•
IEC/EN 61508: 2010 SIL 2
•
IEC/EN 61800-5-2: 2007 SIL 2
•
IEC/EN 62061: 2005 SIL CL2
•
EN ISO 13849-1: 2015
®
The VLT Integrated Servo Drive ISD 510 System has been
tested for higher EMC immunity as described in
EN 61800-5-2:2017.

2.7.2 Abbreviations and Conventions

Abbreviation Reference
Cat.
DC
FIT
HFT
MTTF
D
16
power on to enable communication
AUX
Description
EN ISO Category, level B, 1–4
13849-1
– Diagnostic coverage
– Failure in time
Failure rate: 1E-9/hour
EN IEC 61508 Hardware fault tolerance
H = n means that n + 1 faults may
lead to a loss of the safety
function.
EN ISO Mean time to failure – dangerous
13849-1 Unit: years
Danfoss A/S © 08/2017 All rights reserved.
®
VLT Integrated Servo Drive ISD
Abbreviation Reference
PFH
PFD
PL
SFF
SIL
STO
Table 2.5 Abbreviations and Conventions

2.7.3 Functional Description

The STO function in the VLT
510 System features a separate STO function for each line
of servo drives in daisy-chain format. The function is
activated by inputs on the SAB. Using the STO function
activates the STO for all servo drives on that line. Once the
STO is activated, no torque is generated on the axes. Reset
of the safety function and diagnostics can be carried out
via the PLC.
NOTICE
The ISD 510 servo system does not implement a manual
reset function as required by ISO 13849-1. The standard
failure reset from the PLC cannot be used for this
purpose.
For automatic restart without manual reset, observe the
requirements detailed in paragraph 6.3.3.2.5 of ISO
12100:2010 or equivalent standard.
®
510 System
Description
EN IEC 61508 Probability of dangerous failures
per hour
Take this value into account if the
safety device is operated in high
demand mode or in continuous
operating mode, where the
frequency of demands for
operation made on a safety-related
system occurs more than once per
year.
EN IEC 61508 Average probability of failure on
demand
This value is used for low demand
operation.
EN ISO Performance level
13849-1 A discrete level used to specify the
capability of safety-related parts of
a system to perform safety-
oriented functions under
foreseeable conditions. Levels: a–e.
EN IEC 61508 Safe Failure Fraction [%]
Proportion of safe failures and
detected dangerous failures of a
safety function or a subsystem as a
percentage of all possible failures.
EN IEC 61508 Safety Integrity Level
EN IEC 62061
EN IEC Safe Torque Off
61800-5-2
®
Integrated Servo Drive ISD
MG36C102