Siemens Simatic S7-300 CPU 31xC Series User Manual

Wiring
6.4 Wiring the power supply module and the CPU
S7-300, CPU 31xC and CPU 31x: Installation
6-6 Operating Instructions, Edition 08/2004, A5E00105492-05
Warning
Reversing the polarity of the M and L+ terminals trips the internal fuse on your CPU.
Always interconnect the M and L+ terminals of the power supply module and of the CPU.
6. Close the front panels.
The figure below illustrates the procedures described earlier.
L1
N
L+
M
M
L+
I
M
L+
230V/120V
1
2
3
Key to numbers in the figure
(1) Strain relief of the power supply cable
(2) Connection cables between the PS and CPU
(3) Removable power supply connector
Note
The PS 307 power supply module is equipped with two additional 24 VDC terminals L+ and
M for the supply to I/O modules.

Siemens Simatic S7-300 CPU 31xC Series Specifications

General

Series	S7-300 CPU 31xC
Power Supply	24 V DC
Communication Interfaces	MPI, PROFIBUS DP
Programming Languages	LAD, STL, FBD, SCL
Operating Temperature	0°C to +60°C
Memory	48 KB - 512 KB
Dimensions	40 x 125 x 130 mm (varies by model)