Power Electronics SD700 Series - Addressing Modes; Broadcast Addressing Mode

SD700 SERIES
POWER ELECTRONICS
64
CONTROL CONNECTION
7.3. STO - Safe Torque Off
The STO function is defined as follows:
Power, that can cause rotation, is not applied to the motor. The frequency converter will not provide energy
to the motor, which can generate torque.
For three-phase asynchronous motor, that means to stop supplying alternating three-phase power to the
stator.
This function corresponds with an Emergency Stop Category 0 according to IEC 60204-1. When the drive
is running and the STO function is applied, the motor will freely stop by its own inertia.
The SD700’s STO optional board permits to achieve two Safety Levels for the STO function. The safety
integrity level SIL3 (PLe) requires the use of an external SELV/PELV 24V
DC
source, emergency push
button, and a safety relay SIL3 certified with feedback. For safety integrity, level SIL1 (PLc) it is only
required an external push button. Maximun reaction time of STO function is less than 50ms. See section
7.3.1 and 7.3.2 for additional information.
By using this function, cleaning, emergencies or maintenance work on non-electrical parts of the machinery
can be performed without switching off the input power supply to the drive.
Based on the study of each application and a risk assessment, the designer should define the safety
function required and each safety level.
The STO safety function has been certified by Tüv Rheinland according to IEC/EN 61800-5-2.
CAUTION
The STO safety function does not disconnect the main input power and auxiliary power supply.
The drive disconnects the output motor power supply. Therefore, active conductors may be
present inside so do not carry out electric maintenance tasks without isolating the drive.
Otherwise, it could cause damage to the equipment and lead to injury and death to people.
Do not use the STO function as a normal drive stop.
Figure 7.6 Optional STO board terminals
It is recommended to use double-shielded twisted pair cable for external 24Vdc and safety channels.
Shielded must be connect to ground as it is indicated in the examples.
CON.
Terminal
Description
J1
J1.1 (STO O1)
STO output channel 1
J1.2 (STO O2)
STO output channel 2
J2
J2.1 (GND)
GND
J2.2 (STO I1)
STO input channel 1
J3
J3.1 (STO I2)
STO input channel 2
J3.2 (FB1)
Feedback 1 contact
J3.3 (FB2)
Feedback 2 contact
J6
J6.1 (+24Vdc)
24V
DC
power supply. (24 V
DC
, Max:2W)
J6.2 (GND)
0 V
DC
power supply
[1]
This safety integrity level replaces the older Category 3 according to EN954-1.