Siemens Simatic S7-200 System Manual page 24

Installing an S7-200 Micro PLC
Using the Optional Field Wiring Connector
The optional field wiring fan-out connector (Figure 2-11) allows for field wiring connections to
remain fixed when you remove and re-install the S7-200. Refer to Appendix G for the order
number.
AC
OUTPUTS
Figure 2-11
Guidelines for AC Installation
The following items are general wiring guidelines for AC installations. Refer to Figure 2-12.
Provide a single disconnect switch (1) that removes power from the CPU, all input
circuits, and all output (load) circuits.
Provide overcurrent devices (2) to protect the CPU power supply, the output points, and
the input points. You can also fuse each output point individually for greater protection.
External overcurrent protection for input points is not required when you use the 24 VDC
sensor supply (3) from the Micro PLC. This sensor supply is short-circuit protected.
Connect all S7-200 ground terminals to the closest available earth ground (4) to provide
the highest level of noise immunity. It is recommended that all ground terminals be
connected to a single electrical point. Use 14 AWG or 1.5 mm
DC sensor supply from the base unit may be used for base unit inputs (5), expansion DC
inputs (6), and expansion relay coils (7). This sensor supply is short-circuit protected.
L1
N
PE
Figure 2-12
2-10
1L 0.0 0.1 0.2 2L 0.3 0.4 0.5
Optional Field Wiring Connector
(1) (2)
(4)
Fuse
DO PS
S7-200
DI M L+
AC/DC/Rly
(5) (3)
120/230 VAC Using a Single Overcurrent Switch to Protect the CPU and Load Wiring
Field Wiring
Fan-out Connector
VAC
N L1 85–264
2
wire for this connection.
(6) (7)
DI DO
EM 221 DC EM 222 Rly
S7-200 Programmable Controller System Manual
C79000-G7076-C230-02