Siemens CPU 313C Hardware And Installation Guide

&RQILJXULQJ
S7-300 Automation System, Hardware and Installation: CPU 31xC and CPU 31x
A5E00105492-03
5-19
 &RQILJXULQJDQ6ZLWK8QJURXQGHG5HIHUHQFH3RWHQWLDO
1RW&38[&
,QWURGXFWLRQ
If you install an S7-300 with ungrounded reference potential, any interference
currents that occur are dissipated via an RC system to the ground conductor/local
ground integrated into the CPU.
1RWH
An S7-300 with a CPU 31xC cannot be configured ungrounded.
$SSOLFDWLRQ
In extended systems, the S7-300 may require configuration with grounded
reference potential due to ground-fault monitoring. This is the case, for example, in
chemical industry and power stations.
8QJURXQGHGUHIHUHQFHSRWHQWLDORI&38DQG'3
The diagram illustrates an S7-300 configuration with floating reference potential
M
M
L+
M
10M
<100 nF
3
2
1
Figure 5-8 Creating an ungrounded reference potential on a CPU
7KHGLDJUDPLOOXVWUDWHVXQGHUQXPEHU
 If you implement an ungrounded reference potential in your CPU: Use a
screwdriver with 3.5 mm blade width and push the grounding slide contact forwards
in the direction of the arrow until it snaps into place.
 Ground of internal CPU circuitry
 Rail

Siemens CPU 313C Specifications

General

MPI Interface	Yes
Number of digital inputs	24
Number of digital outputs	16
Number of analog inputs	4
Number of analog outputs	2
Supply voltage	24 V DC
High-speed counters	Yes
Bit Operations Execution Time	0.1 µs
Word Operations Execution Time	0.2 µs
Power Consumption	5 W
Dimensions (W x H x D)	40 x 125 x 130 mm
Operating Temperature	0 to 60 °C
Communication Interfaces	MPI
Programming Languages	LAD, FBD, STL
Product type designation	CPU 313C
Weight	490 g