Siemens SIMATIC PN/J1939 LINK - 7.2 Potential ratios

Connecting
7.3 24 V DC power supply
SIMATIC PN/J1939 LINK
38 Operating Instructions, 12/2018, A5E45307564-AA
7.3
24 V DC power supply
24 V DC power supply
The connection of the external 24 V power supply and the functional earth connection takes
place via a 3-pin screw-type terminal. It is located below the top housing cover
(see Design (Page 14)).
A suitable power supply is, for example, SIMATIC S7-1200 Power Supply PM1207
(6EP1332-1SH71).
Safety information
WARNING
Connection only over safety extra-low voltage / protective extra-low voltage
May cause death or serious injury
The device is designed for operation using directly connectable safety extra-low voltage
(SELV) with safe electrical separation according to IEC 60950-1 / EN 60950-1 /
VDE 0805-1 or IEC 61131-2 / EN 61131-2 / DIN EN 61131-2.
In order to maintain the safe characteristics of the low-voltage circuits of the
PN/J1939 LINK, the 24 V rated voltage supply and external connections to communication
ports must be supplied from approved sources that meet the requirements of various
standards for SELV / PELV voltage-limited sources.
Therefore only connect safety extra-low voltages (SELV) with safe electrical separation
according to IEC 60950-1 / EN 60950-1 / VDE 0805-1 to the supply voltage connections
and the communications interfaces.
Connector pin assignment
The figure below shows the assignment of the terminal for the 24 DC power supply.
Table 7- 1 Terminal assignment for the 24 DC power supply
L+
24 V supply for PN/J1939 LINK (+)
M
24 V supply for PN/J1939 LINK (-)
Functional ground
Permissible torques for screw terminal:
● Minimum tightening torque: 0.5 Nm
● Maximum tightening torque: 0.6 Nm