Installing and connecting the device   
3.3 Connecting the device 
  SIMATIC IPC PX-39A 
46  Operating Instructions, 08/2022, A5E51699601-AA 
3.3.3.3  Connecting the 24 V DC power supply 
Please note the following to ensure you operate the device safely and in accordance with 
regulations: 
 
Safety regulations - connecting cable 
Use only DC connecting cables which comply with the local safety regulations. 
Otherwise, there is a risk of fire and electric shock. This can result in personal injury or 
property damage.  
•  Ensure that the DC connecting cables comply with the safety regulations of the country 
in which the device is installed and bear the marks required in each case. 
 
Connect the protective conductor in accordance with the operating instructions. 
 
The On/Off switch does not fully disconnect the device from the line voltage.  
There is also a risk of fire if the device or connecting lines are damaged. 
•  Always fully disconnect the device from the line voltage before performing work on the 
device or when the device will not be used over an extended period of time. 
•  For control cabinet mounting: Use a central, easily accessible AC circuit breaker close to 
the device, if possible. 
•  When you install the device, make sure that the power supply connector is easily 
 
Approval in accordance with IEC/EN/UL61010 
The device may only be connected to a 24 V DC power supply which meets the 
requirements of a safe extra-low voltage (SELV/PELV) in accordance with the standard 
IEC/UL/EN/DIN EN 61010-2-201.  
Note 
Reverse polarity protection
 
 V DC power supply is protected against polarity reversal. If you mix up the 24 V DC 
connecting cables and ground, the device is not damaged but does not switch on. After the 
power supply has been connected correctly, the device will again be ready to operate.