Siemens SIPROTEC 4 7XT71 Series, Manual, Page: 74 / 122

General Installation
All electrical function groups are accommodated on one printed circuit board assembly. This printed circuit
board assembly also contains a guide plate, an 18-pin plug connector, and the front panel and forms a plug-
gable printed circuit board assembly (this is designated as pluggable printed circuit board assembly in the
following).
The pluggable printed circuit board assembly is fixed in a 1/6 19” housing and electrically connected to the 18-
pin junction block mounted on the rear plate. The pluggable printed circuit board assembly is connected to an
extensive area in the housing interior using contact springs. Due to the electrical properties of the material
used, the housing ensures dissipation and shielding functions.
Grounding the Device
Protective-conductor terminal:
At least one large-scale copper band or conductor must be screwed at 2 contact points in the lower part of
the rear plate using M4 screws (torque: 1.5 Nm).
Use at least a 4-mm
2 protective conductor.
Shielding:
2 contact points are provided for grounding the cable shield.
Degree of protection IP51 applies to the housing (flush-mounting version) and IP20 to the screw terminals of
the junction block. Degree of protection IP20 applies to the surface-mounting version of the device.
i
i
NOTE
You can use the injection unit 7XT71 in panel surface mounting and in panel flush mounting or cabinet
flush mounting, depending on the order code, see chapter
A.1 Ordering Information and Accessories .
2.1
Structure
2.1 General Installation
12 SIPROTEC 4/5, Injection unit 7XT71, Manual
C53000-B1174-C128-8, Edition 05.2020