Power Supply; Connecting The Protective Earth - Siemens SIMATIC IPC477E Operating Instructions Manual

3.3.2

Power supply

3.3.2.1

Connecting the protective earth

A connected protective conductor conducts dangerous electrical charges away from the
metal enclosure. The current flowing through the protective conductor when such a fault
occurs triggers a primary fuse that disconnects the device from the power supply.
The protective conductor also improves the discharge of interference generated by external
power cables, signal cables or cables for I/O devices to ground.
The connection for the protective conductor is labeled with the following symbol:
Electric shock and risk of fire
High voltage may be present in a defective device, which can cause fire or an electric shock
if touched. Death and serious bodily injury can result.
• Connect the device to the protective conductor before you put it into operation.
• The protective conductor connection on the device must be connected to the protective
• Never operate the device without protective conductor.
• If a device is defective, decommission it without delay and mark it accordingly.
Requirement
• The device is installed
• 1 protective conductor, minimum cross section 2.5 mm
• 1 T20 screwdriver
• 1 cable lug for M4
Procedure
The procedure is the same for all device variants and is described here as an example.
1. Clamp the cable lug onto the protective conductor.
2. Connect the cable lug to the screw at the
designated protective conductor connec-
tion.
3. Connect the protective conductor to the protective conductor connection of the control
cabinet in which the device is installed.
SIMATIC IPC477E
Operating Instructions, 11/2020, A5E37455003-AF
WARNING
conductor of the control cabinet or system in which the device is installed.
Mounting and connecting the device
3.3 Connecting the device
= AWG14
2
49