From the characteristics of metal materials, we know that under stress, the wire will inevitably produce a certain creep,which is more serious
in the parallel groove Connector with higher local pressure, which makes the wire slightly thinner and smaller in diameter. Without proper
compensation function, the grip strength of the groove Connector to the wire will decrease, resulting in stress relaxation. When the material
is determined, the wire creep is related to time, pressure, tension and ambient temperature. The greater the pressure or tension on the wire,
the higher the ambient temperature,the more serious the wire creep, and the change curve is exponential, and with time The growth is increasing.
To maintain the stability of the grip of the parallel groove Connector on the wire, during construction and installation, it is necessary to have
enough external force to produce a suitable pressure on the wire to prevent the parallel groove construction and the wire from loosening or
relative slippage; After the external force disappears, the parallel groove Connector should be able to provide a relatively constant pressure on
the wire to compensate for the creep of the wire caused by changes in current, temperature, wind speed, corrosion, etc. When the bolt-type
parallel groove clamp is installed, the torque applied to the bolt or nut is often different from person to person. Generally, no special measuring
instrument is used to review the torque,resulting in different bolts of the same clamp or clamps installed by different personnel. The resulting
pressure on the wire is inconsistent.If the pressure is too high, the wire will creep too much; if the pressure is too small, the clamp and the wire
will lack sufficient pressure and grip in the early stage of operation.The quality of the spring washer also seriously affects the mechanical stability
of the clamp. If a poor spring washer is selected,the plastic deformation of the spring washer will be greater after the external force is applied,
which will cause the clamp after installation to fail to obtain proper pressure compensation when the wire creeps.
Post time: Aug-27-2021