Siemens SINUMERIK 840D sl Manual page 18

Application Planning
2.1 Secondary electrical conditions
It is permissible to have a cluster of operator components for ground connection/PA.
Example: The Control Unit on the swivel arm.
It is sufficient in this instance to connect the ground connections of, for example, the PCU,
TCU and operator panel front using a cable and to route a shared grounding conductor to
the central ground connection in the control cabinet. Minimum cable diameter of 10 mm
Figure 2-2
MB
M
G
PA
SL
The following rules apply for external cable cross sections:
● Minimum PA cross section ≥ 10 mm
● The cable cross section of the central protective conductor is calculated from the cable
Line connection S (mm
S ≤ 16
16 ≤ S ≤ 35
S ≥ 35
18
Grounding concept
Shielded signal cable with reference ground
Motor
Encoder
Equipotential bonding conductor
Protective conductor
cross section of the line connection as follows:
)
2
2
Protective conductor SL min. (mm
S
16
S/2
Manual, 07/2007, 6FC5397-0AP10-2BA0
.
2
)
2
NCU