Installation guide

Safety
890USE17100 September 2003 73
The Functional Earth Connection
Functional Earth
(FE) on the DIN
Rail
The DIN rail for your Advantys STB island is considered the functional earth ground
(FE) plane for your system. Here EFI and RFI is suppressed. The connection
between this ground and your island is made at the contacts on the back of your
island’s NIM and at the back of the I/O bases. It is essential that this connection be
sound.
Rail Mounting
Considerations
If you are using 7.5 mm DIN rail, make sure that the region along the rail where the
island bases will be installed does not have any screw heads on it. The base units
may not make proper contact with the rail if there are screw heads behind them, and
the FE contact may be compromised.
For high vibration environments where the rail needs to be fastened to the mounting
surface along areas where the island modules will be mounted, use 15 mm DIN rail.
The bolt heads on 15 mm rail will be sufficiently recessed so that they do not
interfere with the base-to-rail FE contacts.