Mounting and connecting the device
3.4 Connecting the device
SIMATIC IPC477D, IPC477D PRO
80
Operating Instructions, 11/2016, A5E31347228-AF
3.4.2
Power supply built-in unit
3.4.2.1
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:
WARNING
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
conductor of the control cabinet or system in which the device is installed.
•
Never operate the device without protective conductor.
•
If a device is defective, decommission it without delay and mark it accordingly.
Requirements
●
The device is installed
●
1 protective conductor with minimum core cross-section of 2.5 mm
2
●
1 T20 screwdriver
●
1 cable lug for M4