Technical data

6.9.2 Safety instructions
Drives with a suspended load must have an additional safe mechanical blocking
(e.g. by a motor-holding brake). The amplifier cannot hold the load when STO is
active. That could result in serious injury.
When STO is engaged during operation by separating input STO-Enable from
24VDC, the motor runs down out of control and the servo amplifier displays the
error F27. There is no possibility of braking the drive controlled. If a controlled
braking before the use of STO is necessary, the drive must be braked and the input
STO-ENABLE has to be separated from +24 VDC time-delayed.
If the safety function STO is automatically activated by a control system, then make
sure that the output of the control is monitored for possible malfunction. This can
be used to prevent a faulty output from unintentionally activating the safety
function STO. Since the restart lock is a single-channel system, erroneous
engaging will not be recognized.
The safety function STO does not provide an electrical separation from the power
output. If access to the motor power terminals is necessary, the servo amplifier
must be disconnected from mains supply considering the discharging time of the
DC bus link (intermediate circuit).
Keep to the following functional sequence when the restart lock STO is used :
1. Brake the drive in a controlled manner (speed setpoint = 0V)
2. When speed = 0 rpm, disable the servo amplifier (enable = 0V)
3. If there is a suspended load, block the drive mechanically
4. Activate the restart lock STO
6.9.3 Use as directed
The safety function STO is exclusively intended to provide safety for personnel, by pre-
venting the restart of a system. To achieve this personnel safety, the wiring of the safety
circuits must meet the safety requirements of IEC 60204, ISO 12100, IEC 62061 SIL CL2
respectively ISO 13849-1 PLd.
If STO is automatically activated by a control system, then make sure that the output of
the control is monitored for possible malfunction.
6.9.4 Prohibited Use
The safety function STO must not be used if the drive is to be made inactive for the follo-
wing reasons:
1. - cleaning, maintenance and repair operations
- long inoperative periods
In such cases, the entire system should be disconnected from the supply by the
personnel, and secured (main switch).
2. - emergency-stop situations
In an emergency-stop situation, the main contactor is switched off (by the
emergency-stop button).
36 S300 Instructions Manual
Technical description 09/2011 Kollmorgen