03.06
2.1.3
Grounding concept
The SINUMERIK 840D system consists of a number of individual components,
each of which must comply with the appropriate EMC and safety standards. The
individual system components are:
S
S
S
S
S
S
S
S
The NCU box is a 50 mm wide cassette that is integrated into the infeed/regen-
erative feedback (I/RF) unit, FSD and MSD.
The individual modules are attached to a metal cabinet panel by means of
screws. Make sure that near the screws a low-impedance contact of the NCU
box with the cabinet wall can be made. Insulating paints at the contact point
must be removed. The electronic grounding points of the modules are intercon-
nected via the device and drive bus and at the same time conducted to the
X131 terminal of the I/RF module.
The ground and module ground M should be connected at the power supply
terminal of the IM 361. Further, for the EFP, "SHIELD" and "M24" must be con-
nected in connector X1.
© Siemens AG, 2006. All rights reserved
SINUMERIK 840D Configuring Manual NCU (PHD) – 03.06 Edition
NCU box
Machine control panel MCP
Keyboard
Operator panels (operator panel front + PCU/TCU)
NCU terminal block
Distributor box and handheld unit
S7-300 I/O with IM 361 interface module
Single I/O module
2 Connection Conditions
2.1 Secondary electrical conditions
2-23