Tuesday, March 13, 2012

Safe brake functions

Functions related to holding brakes and service brakes have been summarized under the heading of safe brake functions.





Safe brake control (SBC)
Safe brake control (SBC) supplies a safe output signal to drive an external mechanical brake. The brakes used must be “safety brakes”, in which a quiescent current operates against a spring. If the current flow is interrupted, the brake will engage. Control modules frequently include a power reduction feature when the brake is released to reduce energy consumption or brake heating. A safe brake test may be required to detect errors during operation, depending on the risk analysis.

Holding brakes and service brakes are often used on axes with suspended loads. Along with the brake, the brake drive is another key component in terms of the safety function. The safe brake control (SBC) function is generally used to control the holding brake activated once an axis is at standstill.



Safe brake test (SBT)
Using the safe brake test (SBT) function can significantly increase safety. In many cases, simply controlling a holding brake safely is not enough to make a vertical axis safe. If the wearing, mechanical part of the brake is not maintained regularly, it cannot be guaranteed that the holding brake will apply the designated braking action in the event of danger. The safe brake test (SBT) function provides an automatic test which replaces previous measures that could only be implemented through organizational and manual operations; if the result is negative, it can bring the plant to a standstill and signal an error. This reduces maintenance work  considerably.



No comments:

Post a Comment