Example: S7-300 With Load Power Supply From Ps 307 - Siemens S7-300 Installation Manual

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The figure below shows the overall S7-300 configuration (load power supply unit
and grounding concept), with TN-S mains supply.
Apart from powering the CPU, the PS 307 also supplies the load current for the
24 VDC modules.
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The arrangement of supply connections displayed does not correspond with the
physical arrangement; it was merely selected to give you a clear overview.
L1
L2
L3
N
PE
Figure 5-13 Example: S7-300 with load power supply from PS 307
S7-300 Automation System, Hardware and Installation: CPU 312IFM - 318-2 DP
A5E00203919-01
Low-voltage distribution
e. g. TN-S system (3 x 400 V)
PS
Rail
L1
N
Cabinet
S7-300 CPU SM
µP
L +
M
M
Signal modules
Ground bus in cabinet
DC 24 V load circuit for DC modules
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