3.3.2 Spring-loaded connection
Spring-loaded connection
All SIRIUS monitoring relays have spring-loaded connections. They make wiring quick and
maintenance-free, while also meeting high demands in terms of vibration and shock resistance.
If the cross-section of a connectable wire is greater than 6 mm², the forces required for operation
of the tension spring are so high that the spring-loaded connection can no longer be used in a
problem-free manner. For this reason, size S2 current monitoring relays are only o󹪜ered with
screw-type or spring-loaded terminals in the control circuit. The terminals of the main current
paths are always screw-type terminals.
â‘ Solid
â‘¡ Finely stranded
â‘¢ Stranded
â‘£ Finely stranded with end sleeve
a Spring-loaded terminal
b Busbar
Figure 3-1 Spring-loaded terminal
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 terminal, i.e. two independent connections for each
current path (exception: in the case of 3RR2, terminals of the main current paths have one
clamping point). 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 󹪞at 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.
System overview
3.3 Connection methods
SIRIUS 3UG4 / 3RR2 monitoring relay
Equipment Manual, 07/2021, NEB927043002000/RS-AD/005 25
To Next Page
Loading...
Need help?
General