Validating/Checking The Safety Function - Siemens PM330 Hardware Installation Manual

Description of the response
1 SS1-t is activated in operation.
2 After the response time in the drive has elapsed, the upstream external monitoring and control system (e.g.
3SK1) immediately initiates braking along the OFF3 ramp. At the same time, the SS1-t delay time is started
internally in the external monitoring and control system (e.g. 3SK1).
3 After the SS1-t delay time has expired, the external monitoring and control system (e.g. 3SK1) activates the
Safe Torque Off (STO) function. The motor coasts down to standstill, and as a result of STO, the motor is
safely prevented from restarting.
4 SS1-t and STO are deactivated by deactivating SS1-t and STO at the upstream external monitoring and con-
trol system (e.g. 3SK1), and the inverter is then ready to be switched on again.
To enable the switch-off signal paths using the external monitoring and control system (e.g. 3SK1), the two
feedback signal contacts of the PM330 at terminal strip X41 must be closed.
Depending on the application, the start button may need to be pressed.
5 The inverter can be restarted with the ON/OFF1 signal.
Settings
A SS1-t is activated via the DI at X9.
B The drive is braked along the OFF3 ramp, and after the SS1-t delay time has expired, STO is automatically
initiated in the external monitoring and control system (e.g. 3SK1) independent of the actual speed.
The OFF3 ramp set in the Control Unit must be coordinated with the SS1-t delay time of the external monitor-
ing and control system (e.g. 3SK1). These values are completely independent of one another. The delay time
should be set longer than or equal to the braking ramp, as, after STO is initiated, the drive is no longer braked,
but simply coasts down.
In the diagram above, coasting down can be identified between point 3 and 4. On the other hand, the sche-
matic diagram "SS1-t" shows that STO is activated after standstill.
If the braking ramp does not result in standstill after an acceptable time, then if necessary and external braking
chopper must be used.
C The status SS1-t active can only be retrieved at the external monitoring and control system (e.g. 3SK1) via a
contact or DO; the drive only knows the OFF3 status.
As soon as STO is active, status "[44] switching on inhibited – connect 24 V to terminal STO (hardware)" is
shown in parameter r0002 and can be used for diagnostics. Using this to control specific functions, especially
regarding a safety function, is not permissible.
In this case, directly use the monitoring and control system (e.g. 3SK1).
8.3

Validating/checking the safety function

Carefully check/test the safety function after commissioning the system for the first time,
after carrying out any repairs and after each change to the machine/system.
These tests/checks must be performed by qualified personnel.
Power Module PM330
Hardware Installation Manual, 12/2018, A5E32844552B AF
Safety functions of PM330
8.3 Validating/checking the safety function
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