Siemens SIRIUS 3RH Series, Системное руководство

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System overview
1.9 Connection
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
75
1.9.1.2 Spring-loaded connection
Spring-loaded connection
Spring-loaded connection systems are found consistently on all SIRIUS Innovations
products. They make wiring quick and maintenance-free, while also meeting high demands
in terms of vibration and shock resistance.
D
E
①
Solid
②
Finely stranded
③
Stranded
④
Finely stranded with end sleeve
a Spring-loaded terminal
b Busbar
Figure 1-33 Spring-loaded terminal
The spring-loaded terminal on the switching devices clamps copper conductors from 0.25
mm
2
(removable terminal) to 10 mm
2
(main circuit terminal, size S0). For more details, see
the information about conductor cross-sections in the chapter titled "Conductor cross-
sections for spring-loaded connection systems (Page 82)". The conductors can be clamped
directly or you can pre-treat them to add a form of splice protection. This could involve
attaching end sleeves or pin cable lugs to the ends of the conductors; the tidiest solution is to
use conductors whose ends have been sealed by means of ultrasound.
The devices are equipped with a two-wire connection, i.e. two independent connections per
current path. Just one conductor is connected to each clamping point. The spring-loaded
terminal presses the conductor against the busbar, which curves around inside the terminal.
The high contact pressure per unit area achieved in this way is gas-tight. The spring-loaded
terminal presses flat against the conductor, but does not damage it. The spring force of the
spring-loaded terminal has been dimensioned such that the clamping force adjusts to the
conductor diameter automatically. This ensures that any conductor deformation caused by
settling, creepage, or yielding is compensated for. The clamping point cannot become loose
of its own accord. This connection is vibration- and shock-proof. Vibrations or shocks will not
damage the conductor, nor will they cause contact separation. These terminals are
particularly well suited for use with machines and systems which are subject to stresses
such as these, e.g. vibrators, rail vehicles, and elevators.
The contact pressure between the conductor and the busbar is set to an optimum level, so
this clamp connection is appropriate for high-voltage applications, as well as for transferring
voltages and currents in the mV or mA range within instrumentation and electronic
components.