4.6.1 Description
On the MDS 5000 inverter the safety function "safe torque off" can be implemented with option ASP 5001. When the safety
function is used the inverter must be able to be switched off in two different ways. The first way to switch off the inverter uses
the enable function. Diagnosis is performed via a binary output of the options SEA 5000, REA 5000, XEA 5001 or a fieldbus
system.
The second way to switch off the inverter uses the ASP 5001 option in addition. When the ASP 5001 option is activated, control
of the end stage is switched off with the positively-driven switch elements of a safety relay. The reference value input is
disabled, and the signal contact is switched to an external safety circuit (break contact). The motor cannot start up even when
there are defects in the end stage or the control circuit since the necessary phase sequence is no longer generated.
Advantages of the ASP 5001 option:
• No switching of the network voltage necessary and the DC link remains charged. This permits a faster restart.
• Less contact wear since only low voltage is switched.
• Less additional wiring work.
4.6.2 Use
WARNING
The starting lockout option only switches off the end stage. Dangerous voltages may still be
present on the motor terminals!
This means that the starting lockout option does not provide galvanic isolation from the
power network. The function does not provide protection against "electrical shock."
During maintenance or repair work an appropriate voltage-free circuit and system protection
are required.
The regulations for emergency off situations must be adhered to.
WARNING
Since the safety function ensures that the motor torque is switched off, axes that are moving
vertically must be protected against crashing down.
WARNING
Since the motor may run down in an undefined state when the starting lockout is activated
during operation, it is essential to adhere to the switchoff sequences which will be described
in the following section (1st and 2nd ways to switch off).