Connecting The Power Supply To The Cfu - Siemens Simatic CFU Commissioning Manual

Connecting

7.3 Connecting the power supply to the CFU

Additional information
● You can find information about required tools in section "Tools and tightening torques
(Page 149)".
● You can find information about cables and wire end ferrules in section "Cable cross-sections
and wire end ferrules (Page 45)".
7.3 Connecting the power supply to the CFU
Introduction
The power supply of the CFU is fed via two 2-pole connection plugs that are capable of feed-
through wiring and are located on the front of the CFU.
You can find information on power consumption of the CFU in section "Technical specifications
of the Compact Field Unit PA (Page 138)".
Power supply unit
Only use power supply units of type SELV/PELV with safe electrically isolated functional extra
low voltage (≤ 28.8 V DC).
Safety extra-low voltage
The device is designed for operation with a directly connectable safety extra-low voltage
(SELV) from a limited power source (LPS).
For this reason, only safety extra-low voltages (SELV) with limited power source (LPS)
according to IEC 60950‑1 / EN 60950‑1 / VDE 0805‑1 may be connected to the supply
connections or the power supply unit for the device must comply with NEC Class 2 according
to the National Electrical Code (r) (ANSI / NFPA 70).
Non-permissible power supply
In a configuration with a redundant power supply (two separate power supplies), both must
meet these requirements.
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WARNING
WARNING
Commissioning Manual, 07/2018, A5E39252870-AC
SIMATIC CFU