ABB ACH580-34 Guía Rápida De Instalación Y Puesta En Marcha página 290

290 Technical data and references
the drive in case of danger (such as an emergency stop circuit). When activated, the
STO function disables the control voltage of the power semiconductors of the drive
output stage, thus preventing the drive from generating the torque required to rotate
the motor. The control program generates an indication as defined by parameter
31.22 . If the motor is running when Safe torque off is activated, it coasts to a stop.
Closing the activation switch deactivates the STO. Any faults generated must be reset
before restarting.
The STO function has a redundant architecture, that is, both channels must be used
in the safety function implementation. The safety data given is calculated for redundant
use, and does not apply if both channels are not used.
The STO function does not disconnect the voltage from the main and auxiliary
circuits of the drive.
Notes:
• If stopping by coasting is not acceptable, stop the drive and machinery using the
appropriate stop mode before activating the STO.
• The STO function overrides all other functions of the drive.
Wiring
￭
For the electrical specifications of the STO connection, see the technical data of the
control unit.
The contacts of the relay [K] must open/close within 200 ms of each other.
Double-shielded twisted-pair cable is recommended for the connection. The maximum
length of the cabling between the switch and the drive control unit is 300 m (1000 ft).
Ground the shield of the cable at the control unit only.
Note: A short-circuit in the STO wiring causes a dangerous fault. Therefore, it is
recommended to use a safety relay (including wiring diagnostics) and/or a wiring
method (shield grounding, channel separation) which reduces or eliminates the risk
caused by the short-circuit.
Validation
￭
To ensure the safe operation of a safety function, a validation test is required. The
test must be carried out by a competent person with adequate expertise and
knowledge of the safety function. The test procedures and report must be documented
and signed by this person.
Technical data
￭
• Minimum voltage at IN1 and IN2 to be interpreted as "1": 13 V DC
• STO reaction time (shortest detectable break): 1 ms
• STO response time: 2 ms (typical), 30 ms (maximum)
• Fault detection time: Channels in different states for longer than 200 ms
• Fault reaction time: Fault detection time + 10 ms
• STO fault indication (parameter 31.22) delay: < 500 ms
• STO warning indication (parameter 31.22) delay: < 1000 ms