Siemens SINUMERIK 840D sl Manual page 140

Connection of the Components
5.7 Control Supply Module (CSM)
Use of several Control Supply Modules, division of the consumer lines
An additional CSM must be provided if the load caused by the supplied consumers causes
the maximum output current (20 A) of the CSM to be exceeded. The 24 VDC busbar must
not be jumpered in front of the new infeed, because a new potential begins after the
additional infeed.
Figure 5-22
The corresponding different supply lines must be configured and constructed depending on
the size of the drive group and the overall length. This ensures that should one line fail, the
power supply to all attached consumers does not fail. The fault-free consumer lines remain
operational.
5-56
Note
The maximum length of the supply cables for the 24 VDC electronic power supply
between the power supply and the SINAMICS components must not exceed 10 meters.
The connection cable does not need to be shielded nor twisted. The maximum value of
the ripple voltage, however, must not be exceeded. If this is not the case, shielded or
twisted cables should be used.
24 VDC division
Guide for the SINUMERIK 840D sl machine configuring
Manual, 07/2006 Edition, 6FC5397-6CP10-0BA0