Application Examples; Sistema Data; Emergency Stop Of Drive With Sto - Category 1, Pl C, Sil1 - Danfoss VLT FC Series Operating Manual

Safe Torque Off
Operating Guide

5 Application Examples

5.1 SISTEMA Data

SISTEMA (Safety Integrity Software Tool for the Evaluation of Machine Applications) is a software utility that provides developers
and testers of safety-related machine controls with comprehensive support in the evaluation of safety in the context of ISO 13849-1.
Functional safety data are available from a data library for use with the SISTEMA calculation tool from the ISA (Institute for Occupa-
tional Safety and Health of the German Social Accident Insurance), and data for manual calculation. SISTEMA is available for down-
load at www.danfoss.com in the Service and support/downloads sections.

5.2 Emergency Stop of Drive with STO - Category 1, PL c, SIL1

+24 V
FC
2
1
37
Illustration 4: Application Example, Emergency Stop with STO, Category 1, PL c, SIL1
1 Emergency stop button.
2 Short-circuit protected cable.
Safety function
If there is an emergency, the emergency stop device is activated. The STO function of the drive is activated. Following a stop or
emergency stop command, the drive is halted.
Design features
• The circuit can be used up to Category 1, PL c (ISO 13849-1) or SIL1 (EN 62061 and IEC 61508).
• The STO function is activated via 1 NC positively operated switch contact (according to IEC 60947-1, IEC 60947-5-1, and IEC
60947-5-5).
• The PL c, the complete safety functions have to be calculated (MTTFd).
• Use the basic safety principles.
• Devices used for activation of STO must be suitable for the selected Category, PL, or SIL.
When implementing the emergency stop, pay attention to the following tips:
• Any non-safety related standards should be fulfilled for the application and its components.
• The application designer is responsible for selecting suitable components.
• To fulfill PL c, the MTTFd and DC for the whole safety function have to be calculated.
• The B value of the emergency stop device shall be known. The B
10d
ing to PL c.
Implementation in SISTEMA using Danfoss VLT library
As an example, use the subsystem "VLT® AutomationDrive FC 302/FCD 302 Safe Torque Off (Terminal 37)". There is no need to edit
all the parameters which are set in the library.
SB emergency
stop device
Illustration 5: Safety-related Block Diagram
16 | Danfoss A/S © 2021.03
SB FC 300 safe stop
(terminal 37)
from Danfoss VLT library
value has to be high enough to fulfill MTTFd correspond-
10d
AQ313340186453en-00101 / 130R0544
Application Examples