Installing and connecting the device
3.3 Connecting the device
SIMATIC IPC BX-39A
40 Operating Instructions, 07/2022, A5E50715883-AA
3.3.2.2 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. The power supply must fulfill the requirements of NEC
Class 2 or Limited Energy according to IEC/UL/EN/DIN EN 61010-2-201.
• If the device is installed in an enclosure that complies with section 9.3.2. c) of
IEC/UL/EN/DIN-EN 61010-1 and IEC/UL/EN/DIN-EN 61010-2-201, it can be supplied from a
source "higher than NEC Class 2 / Limited Energy". The device is then classified as "OPEN
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.