Compax3 device description
34
192-120102 N7 - February 2004
3.4
Safety function – safe standstill -
You can read about the following in this chapter:
Safety instructions concerning the function „Safe Standstill“ ...........................................................36
Application examples „Safe Standstill“ ............................................................................................37
Compax3 is equipped with the "Safe Standstill" safety feature.
The “protection against unexpected start-up“ described in EN1037 can be
implemented with this feature.
Principle:
To ensure safe protection against a motor starting up unexpectedly, the flow of
current to the motor and thus to the power output stage must be prevented.
This is accomplished for Compax3 with two measures independent of each other
(Channel 1 and 2), without disconnecting the drive from the power supply:
Channel 1:
Activation of the power output stage can be disabled in the Compax3 controller by
means of a digital input or with a fieldbus interface (depending on the Compax3
device type) (deactivation of the energize input).
Channel 2:
The power supply for optocouplers and drivers of power output stage signals is
disconnected by a safety relay activated by the “ENABLE“ (X4/3) input and
equipped with force-directed contacts. This prevents control signals from being
transferred to the power output stage.
The „Safe Standstill“ safety function as defined by EN 954-1 Category 3
is only possible if both channels are used.
