Siemens Simatic M7-400, Руководство по установке

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Wiring the S7-400
4-6
S7-400 and M7-400 Programmable Controllers Hardware and Installation
A5E00069481-04
Table 4-1 VDE Specifications for Assembling a Programmable Controller
Compare ... Ref. to
Figure
4-1
VDE 0100 VDE 0113
Disconnection element for control
system, sensors, and actuators ... Part 460:
Main switches ... Part 1:
Isolating switches
Short-circuit and overload protection:
in groups for sensors and actuators ... Part 725:
Single-pole
protection of
circuits ... Part 1:
•
With
grounded
secondary
circuit:
single-pole
protection
•
Otherwise:
all-pole
protection
Load current PS for AC power circuits
with more than five items of
electromagnetic apparatus Isolation by
transformer is
recommended Isolation by
transformer is
required
Rule: Grounding the Load Current Circuits
Load current circuits should be grounded.
Reliable functional safety is provided by the common reference potential (ground).
Provide a detachable connection to the protective ground conductor at the load
current power supply (Terminal L- or M) or on the isolating transformer
(Figure 4-1,
). In the event of faults in the power distribution, this will facilitate the
locating of ground faults.