The standard IEC 61800-5-2 (in Europe EN 61800-5-2) deals with the functional safety requirements of “adjustable speed electrical power drive systems”. Part 5-2 of the international standard series EN / IEC 61800 is a product standard for electrical drive systems with integrated safety functions. Part 5-2 specifies the requirements for the development of safe drives in terms of their functional safety considerations.
By implementing and complying with the normative regulations, manufacturers are able to install safe drives in plant and machinery in accordance with the specifications of the overarching standards EN / IEC 61508 (generic standard for functional safety of electrical and electronic systems), EN / IEC 62061 (functional safety of machine control systems) and EN ISO 13849 (machinery safety).
The standard EN 61800-5-2 divides safety functions into stop functions and miscellaneous safety functions such as safe motion functions or safe brake functions.
When considering safety on axes, the main factors are to prevent the axes from starting up unexpectedly and to shut down moving axes safely in the case of danger. EN / IEC 61800-5-2 defines three stop functions, which correspond to the three stop categories 0, 1 and 2 from EN / IEC 60204-1:
| EN / IEC 60204-1 | EN / IEC 61800-5-2 |
| Stop category 0 | Safe torque off STO |
| Stop category 1 | Safe stop 1 SS1 |
| Stop category 2 | Safe stop 2 SS2 |
If faults or limit value violations are identified by the safety functions, defined reaction functions must be initiated. EN / IEC 61800-5-2 frequently talks of the limiting of speeds or positions. This is achieved by initiating a motor stop as a reaction function if a limit value is violated. There are also applications in which a direct shutdown in the case of a limit value violation is merely reported by the individual axis and a higher-level safety controller takes care of coordinated braking of the entire system of axes. Equally, external monitoring devices can merely report limit value violations. In combination with a safe shutdown path, the requirements of the normative safety functions can then be satisfied. A drive-integrated motion monitoring solution can be implemented using our PMCprotego DS.
In addition to the stop functions, IEC 61800-5-2 also describes the “safe motion functions”, which are intended to reduce risks during operation. A safe monitoring function can be considered a supplementary safety function: the monitoring function is based on the normative motion function. Exceeding the parameters set for limit values is reported, but does not trigger an error reaction function.
Rely on safe motion monitoring on products from Pilz!