2.3 Safe handling
High voltages from external supplies
Even if the circuit breaker is open, parts of the drive can be under voltage (live) as a result of
the auxiliary voltage at the premagnetization, precharging or demagnetization transformers.
This danger is not limited to the drive, but can also occur with components that are electrically
connected to the drive (e.g. circuit breakers or isolators). Touching live components can result
in death, serious injury, or material damage.
Therefore, isolate all components that can feed voltage to the drive before commencing work.
High voltages during operation
When operating this equipment very high voltages develop. Even after switching off the mains
voltage, or while the connected machine is still turning, high voltages can remain for a
prolonged length of time. High voltages can cause death or serious injury if the safety rules
are not observed or if the equipment is handled incorrectly.
● Operate the drive properly.
● Always follow the "The five safety rules (Page 13)" when performing any work.
● Only remove the covers using the methods described by these operating instructions.
● Maintain the drive regularly and correctly.
High voltages from machines still turning and connected
Rotating machinery can induce dangerous high voltages and synchronous motors that are
not de-excited immediately can also pose a hazard. If the connection to the motor is not
isolated or grounded, these voltages can also remain. If live parts are touched, this can result
in death and serious physical injuries.
Before opening the doors, wait until the connected machine has come to a standstill.
High voltages from DC-link capacitors
High voltages are still present at the DC-link capacitors even after shutdown. If live parts are
touched, this can result in death or serious physical injury.
● Wait for the DC-link capacitor's discharge time specified on the device label. Do not touch
● Observe the five safety rules when performing any work.
the device during this time.
SINAMICS SM120 6SL38715
Operating Instructions 07/2015