Application Planning; Grounding Concept - Siemens SINUMERIK ONE PPU 1740 Series Equipment Manual

Application planning

4.1

Grounding concept

Components
The SINUMERIK ONE system consists of a number of individual components which have been
designed so that the system complies with the appropriate EMC and safety standards. The
individual system components are:
● Panel Processing Unit PPU
● PLC I/O modules
● S7-1500 I/O devices
● SINAMICS S120 drive components
Grounding measures
The PPU and machine control panel are attached with tension jacks to a metal mounting panel
on the operator panel. Both have a protective conductor connection for grounding (grounding
screw) at the rear of the device, which must be connected to the grounding bar of the control
cabinet or the operator panel housing.
The PLC I/O modules are installed in the control cabinet and grounded via a grounding screw.
The SINAMICS S120 drive system is installed in the control cabinet. The electronic grounds of
the modules are connected to each other via DRIVE-CLiQ. The modules are grounded either
via the galvanized mounting plate or via the grounding lugs on the front of the modules.
Requirements of the cable cross-section
The following rules apply for external cable cross-sections:
● PA cross-section ≥ 10 mm
● The cable cross-section of the external protective conductor is calculated from the cable
cross-section of the line connection as follows:
PPU 1740
Equipment Manual, 01/2019, A5E47615272B AA
Line connection S [mm ]
2
S ≤ 16
16 ≤ S ≤ 35
S ≥ 35
2
External protective conductor min. [mm
S
16
S/2
4
]
2
43