Siemens SIMATIC S5-100U, System Manual

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Installation Guidelines S5-100U
3.3 Electrical Configuration
3.3.1 Electrical Configuration for the S5-100U
Power Supply
The entire control for the S5-100U consists of the following separate electrical circuits:
• Control circuit for the S5-100U (24 V DC)
• Control circuit for the sensors (24 V DC)
• Load circuit for the actuators (24 V DC or 115/230 V AC)
Control Circuit
The power source for the control circuit supplies the CPU, the bus units, the programmer interface,
and the internal control circuits for the I/O modules. When the incoming supply is 24 V DC/1 A, the
PS 931 power supply module provides an internal supply of +9 V up to a total of 1 A current input
to the I/O modules. The grounding spring on the CPU forces the control circuit to be connected to
the standard mounting rail. The grounding spring must also be protected from interference. The
grounding spring must be grounded.
Load Circuit
The power source for the load circuit supplies the actuators of the process peripherals.
It is suggested that you use one of the following for a 24 V DC power supply:
• The PS 931 power supply module (see Chapter 14)
• A Siemens load power supply from the 6EV1 series (see Appendix D)
If you use load power supplies other than the recommended ones, make certain that the load
voltage is in the range of 20 to 30 V (including ripple).
Note
If you use a switched-mode power supply unit to supply floating analog modules and
BEROs, then this supply must be filtered through a network.
You can connect several mutually independent load circuits adjacent to each other on a single
programmable controller. These connections can either be non-floating or floating (see
section 3.3.3).
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EWA 4NEB 812 6120-02b