The control functions Stop, Emergency Stop and Emergency Off are defined by IEC"International Electrotechnical Commission" IEC is a not-for-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies 60204. Notes for safety aspects of these functions can be found in ISO 13849 and IEC 62061.
|
No functional safety!
|
The stop function shuts down the machine in normal operation. The stop function is defined by IEC 60204.
Stop function must have priority over assigned start functions. The following stop categories are defined:
Stop Category 0
Shut-down by immediate switching-off the energy supply to the drive machinery (this is an uncontrolled shut-down). With the approved safety function STO the drive can be stopped using its internal electronics (IEC 62061 SIL2).
Stop Category 1
A controlled shut-down, whereby the energy supply to the drive machinery is maintained to perform the shut-down, and the energy supply is only interrupted when the shut-down has been completed.
Stop Category 2
A controlled shut-down, whereby the energy supply to the drive machinery is maintained.
Stop Category 0 and Stop Category 1 stops must be operable independently of the operating mode, whereby a Category 0 stop must have priority.
If necessary, provision must be made for the connection of protective devices and lock-outs. If applicable, the stop function must signal its status to the control logic. A reset of the stop function must not create a hazardous situation.
The Emergency Stop function is used for the fastest possible shutdown of the machine in a dangerous situation. The Emergency Stop function is defined by IEC 60204. Principles of emergency stop devices and functional aspects are defined in ISO 13850.
The Emergency Stop function will be triggered by the manual actions of a single person. It must be fully functional and available at all times. The user must understand instantly how to operate this mechanism (without consulting references or instructions).
In addition to the requirements for stop, the Emergency Stop must fulfil the following requirements:
The Emergency Off function is used to switch-off the electrical power supply of the machine. This is done to prevent users from any risk from electrical energy (for example electrical impact). Functional aspects for Emergency Off are defined in IEC 60364-5-53.
The Emergency Off function will be triggered by the manual actions of a single person.
Emergency Off is done by switching off the supply energy by electro-mechanical switching devices. This results in a category 0 stop. If this stop category is not possible in the application, then the Emergency Off function must be replaced by other measures (for example by protection against direct touching).
|
Copyright © 2015 Kollmorgen™ |
|