￭
Relevant failure modes
Relevant failure modes are:
• the main contactor/breaker does not open when requested. (All contactor/breaker failures
are considered dangerous.)
• internal failures of safety relays and the emergency stop button. These failures are
included in the PFH value of the function.
￭
Fault exclusions
Fault exclusions (not considered in the calculations):
• short and open circuits in the cables of the safety circuit
• short and open circuits in the cabinet terminal blocks of the safety circuits.
￭
Operation delays
Emergency stop total delay: less than 250 ms.
Ambient conditions
For the environmental limits for the safety functions and the drive, refer to the drive hardware
manual.
Related standards and directives
Name
Standard
Safety of machinery – General principles for design – Risk assessment and risk reduction
EN ISO 12100:2010
Safety of machinery – Safety-related parts of control systems – Part 1: General principles
for design
EN ISO 13849-
1:2015
Safety of machinery – Safety-related parts of control systems – Part 2: Validation
EN ISO 13849-
2:2012
Safety of machinery – Emergency stop – Principles for design
EN ISO 13850:2015
Safety of machinery – Electrical equipment of machines – Part 1: General requirements
EN 60204-1:2018
IEC 60204-1:2016
Electrical equipment for measurement, control and laboratory use - EMC requirements
- Part 3-1: Immunity requirements for safety-related systems and for equipment intended
to perform safety-related functions (functional safety) - General industrial applications
IEC 61326-3-1:2017
Functional safety of electrical/electronic/programmable electronic safety-related systems
- Part 1: General requirements
IEC 61508-1:2010
Functional safety of electrical/electronic/programmable electronic safety-related systems
- Part 2: Requirements for electrical/electronic/programmable electronic safety-related
systems
IEC 61508-2:2010
Functional safety – Safety instrumented systems for the process industry sector – Part
1: Framework, definitions, system, hardware and application programming requirements
IEC 61511-1:2016
Adjustable speed electrical power drive systems – Part 5-2: Safety requirements –
Functional
EN 61800-5-2:2007
IEC 61800-5-2:2016
Technical data 37