Safe Torque Off - WEG SCA06 Serie Manual Del Usuario

DANGER!
Always disconnect the general power supply before touching any
„
electrical component associated to the servodrive.
Many components may remain charged with high voltages and/or
„
moving (fans), even after the AC power supply input is disconnected
or turned off.
Wait for at least ten minutes so as to guarantee the full discharge
„
of the capacitors.
Always connect the frame of the equipment to the protection
„
grounding (PE) at the proper point.
ATTENTION!
The electronic boards have components sensitive to electrostatic
discharges. Do not touch directly the components or connectors.
If necessary, first touch the grounded metallic frame or use proper
grounding strap.

2.3 SAFE TORQUE OFF

The SCA06 servodrive can be equipped with a redundant dual channel Safe Torque
Off (STO) function.
The STO function acts on the removal of torque from the motor, i.e., no power that can
cause torque is present on the motor after enabling the Safe Torque Off function. The
difference of the Safe Torque Off function from a normal way to disable the motor is
that the first one does it with very high levels of reliability against unexpected motor
starts, even under a fault condition. For this reason, it is allowed to be used where safety
must be guaranteed. See safety specifications presented at the end of this chapter.
Once activated, the STO function removes the power from the electronics, causing
the motor to coast due to the load inertia. See
ATTENTION!
While the Safe Torque Off mode is activated, hazardous voltages may
still be present on the motor. Before any intervention on electrical parts,
the whole system must be deenergized.
ATTENTION!
In circumstances where external influences, e.g., falling of suspended
loads are present, additional measures like mechanical brakes, for
example, may be necessary to prevent any hazard.
A risk analysis must be performed by the end user in order to identify
and cover all possible risks and hazards.
General Information
Figure 2.1 on page 12.
SCA06 | 11