Rexroth Diax 04 HDD and HDS
Appendix
6-1
DOK-DIAX04-HDD+HDS*UL*-IB01-EN-P
6 Appendix
6.1
Discharging of DC Bus Capacitors
In the drive system capacitors are used in the DC bus as energy stores.
In the drive controllers and particularly in the supply units such capacitors
have already been integrated.
Energy stores maintain their energy even when energy supply has been
cut off and have to be discharged before somebody gets in contact with
them.
Discharging devices have been integrated in the components of the drive
system; within the indicated discharging time these devices discharge the
voltage below the allowed 50 V.
If additional capacitances in the form of
•
DC bus capacitor units or
•
additional
capacitors
are connected, make sure that these capacitors, too, are discharged
before somebody gets in contact with them.
Due to the operating principle, the discharging time is the longer
•
the bigger the energy store (the capacitance value)
•
the higher the voltage to which the energy store has been charged
•
the greater the resistance for discharging the capacitors.
Components of the drive system have been dimensioned in such a way
that after the energy supply was cut off the voltage value falls below 50 V
within a discharging time of a maximum of 30 minutes.
WARNING
Lethal electric shock caused by live parts with
more than 50 V!
⇒
Wait at least 30 minutes after switching off power to
allow discharging.
⇒
Check whether voltage has fallen below 50 V before
touching live parts!
To shorten the waiting time until voltage has fallen below 50 V you can
take the following measures:
•
Activate the function "ZKS" (DC bus short circuit)
WARNING
Lethal electric shock caused by live parts with
more than 50 V!
⇒
Before touching live parts check whether the voltage
has fallen below 50 V!
•
Use the discharging device described below.
