Universal system for testing cable elasticity resistance
case study
Universal system for testing cable elasticity resistance is mostly used for testing of network cables. Tests are made by charging with defined electric current. The test is controled by computer, which records the results.
Device consists of
- swinging and fixative appliance, which provides swing out by 90 degrees about vertical ax and swinging in range of maximum 90 degrees symmetrical to verical ax
- axis of shearing appliance for each of 6 testing wire, which enables disconnect mechanical charging of testing wire in case of current interruption
- appliance with slots for supply wiring
- cabinet includes transference mechanizm and alternate three-phase motor
- control cabinet with frequency convertor and electro-equipage
- computer with input-output modules, „hard-disk“ and one floppy drive 1,44MB, monochromatic monitor
- printer for printing reports about testing
- llaboratory constant source MESIT max 40A/40V for current charging of tested wires
Function description
Testing samples are fix to swinging appliance of testing device, so as sample is in the middle of its trajectory and ax of supply is vertical in place where it pass to the electric subject and pass through of swinging ax. Single conductors of testing wires are interconnected to series. In ths way interconnected wires are connected on defined current (current value is defined on the laboratory source) and charged with defined weights.
Before testing, the comparator evaluates if the source is turn on. By contactor bracing, output from source passes to series connection of testing wires. Ovewrflowed current value thourg wires is defined by adjusted current restriction. At source outlet is very small potencial correspondent to loss on serial connected testing wires. In case of interruption of any tested wires will potencial increase to the value defined on the source.
In such a case, single wires are one by one bypass with relay contacts. At bypass of aborted wire, the potential on the output of souce will be lower and identify what wire is aborted.
For testing if the source was not demage by this test, will be current to wire serial connection periodicaly interupted (the period - for example 5min. is possible to defined by computer) and there will be test for voltage increase on the source output. Demaged wire will be cut away by pneumatic actuator.
