Search results
Results from the WOW.Com Content Network
An SIS is intended to perform specific control functions to prevent unsafe process operations when unacceptable or dangerous conditions occur. Because of its criticality, safety instrumented systems must be independent from all other control systems that control the same equipment, in order to ensure SIS functionality is not compromised.
A risk assessment effort yields a target SIL for each safety function. For any given design the achieved SIL is evaluated by three measures: 1. Systematic Capability (SC) which is a measure of design quality. Each device in the design has an SC rating. The SIL of the safety function is limited to smallest SC rating of the devices used.
The STO function is the most common and basic drive-integrated safety function. It ensures that no torque-generating energy can continue to act upon a motor and prevents unintentional starting. [ 1 ]
As such, safety relays monitor a specific function. When connected to other safety relays, they guarantee full monitoring of a plant or machine. [1] They meet the requirements of EN 60947-5-1, EN 60204-1 and VDE 0113-1. [5] Furthermore, there are many variants of safety relays, which are suitable for various machinery applications.
Certification is achieved by proving the functional safety capability (FSC) of the organization, usually by assessment of its functional safety management (FSM) program, and the assessment of the design and life-cycle activities of the product to be certified, which is conducted based on specifications, design documents, test specifications and ...
Although functionally separate, process control and shutdown systems are usually interfaced under one system, called an integrated control and safety system (ICSS). Shutdown systems typically use equipment that is SIL 2 certified as a minimum, whereas control systems can start with SIL 1. SIL applies to both hardware and software requirements ...
An industrial control system (ICS) is an electronic control system and associated instrumentation used for industrial process control. Control systems can range in size from a few modular panel-mounted controllers to large interconnected and interactive distributed control systems (DCSs) with many thousands of field connections.
Functional safety is achieved when every specified safety function is carried out and the level of performance required of each safety function is met. This is normally achieved by a process that includes the following steps as a minimum: Identifying what the required safety functions are. This means the hazards and safety functions have to be ...