MAR2-E-191
2.4. Safety and instructions
2.4.1. General safety description
Only qualified personnel may operate when the equipment is working.
The power supply from the drive to the motor can be turned off “safely”. In this way, the motor can no longer generate
torque when the safe power stage is disabled.
The drives may have uncovered live parts during operation, depending on the level of mechanical protection offered by
the installation in the distribution board. During normal operation, equipment must not be accessible, and all covers and
hatches of the distribution board must be kept closed.
Control and power connections may be live, even though the motor is not rotating.
During operation, the drives may reach temperatures as high as 80 °C.
Voltage arcs may occur and cause damage to people and contacts; this means that electrical connections must not be
loosened or disconnected when the drives are live, and that operators must wait at least six minutes after the power has
been turned off before touching live components or loosening connections.
Capacitors may still have dangerous voltages up to six minutes after switching off the mains voltage. To be sure that
conditions are safe, measure the voltage on the direct-current (BUS) circuit and wait until it has dropped below 40 V.
2.4.2. STO safety function
2.4.2.1. Description
D
R
2020 drives are equipped with the STO (Safety Torque Off) function as standard, which protects (personnel) against
the drive stating up unintentionally.
The standard version of the D
R
2020 has the STO function to use as an interlock against accidental motor restarts. The
STO function may be used to turn off the power supply, to prevent accidental start-up.
The function disables the control voltage of the converter output stage power semiconductors, preventing the drive
from generating the voltage requested to rotate the motor.
By using this function, short-term operations and/or maintenance can be carried out on non-electrical parts of
equipment without turning off the power supply.
This function must be enabled by a safe external control (mechanical or semiconductor) or by a dedicated external safety
board. See section “7.3. Safe Torque Off function” for more information.
WARNING
Suspended loads must always be mechanically secured in a safe way. If enabled, the STO function does not guarantee
that suspended loads will be held
WARNING
Turning off the 24 V DC from the two STO connector inputs means that the motor is not controlled
WARNING
The STO function is not electrically independent of the power output. If you need to work on the motor cable, turn off
the power supply to the drive and wait for the intermediate circuit discharge time to finish
CAUTION
When using the STO function, observe the following operating sequence
ATTENTION
Lorsque vous utilisez la fonction STO, observez la séquence d'exploitation suivante
Tab. 2.7 Eletrical specifications - STO functions
27
1.
Stop movement in a regulated manner, setting the nominal velocity value to zero
/
Arrêter le mouvement de manière régulée, définissant la valeur de vitesse nominale à zéro
2.
Once zero speed has been reached, and in the case of suspended loads, mechanically secure the load
/
Une fois la vitesse zéro a été atteinte, et dans le cas de charges suspendues, fixer mécaniquement la
charge
3.
Disable the drive and, at this point, activate the STO function
/
Désactiver l'unité et, à ce point, activer la fonction STO
Input voltage
24 V DC +/- 10 %
Maximum input current
50 mA
