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Aircraft cables test system according to standard BS 3G 230:2000

Test system for resistance to cable-to-cable abrasion, to electric overload and to dry and wet arc tracking

31-08-2022

 

Following a request from a long-standing customer-partner, SIF has decided to create a test system for a sector of great strategic importance such as that of aviation and defence. For an area where precision, quality and reliability of the products are fundamental, even the cables must be tested in the most severe conditions and be subjected to very specific and detailed tests, dictated by very stringent standards.

The customer could not find a supplier able to study a system suitable for their needs and able to carry out the four different tests with as many equipment. Very few details available that obviously did not deal with anything with respect to the design and development of the test systems.

The requirements of the customer were the following:

  1. Compliance with BS 3G 230: 2000 standards
  2. Demonstration of the compliance of the equipment with the standards
  3. Safety, Performance, Reliability and Functionality
  4. Aesthetics
  5. Data Acquisition and Industry 4.0

The unspoken customer requirements that SIF was able to catch were:

  1. Space optimization
  2. Ease of use
  3. Automation of system efficiency checks required by the standard
  4. Speed of preparation of the test set
  5. Speed of preparing cable sets for testing
  6. Remote communication of the events that occur during the tests
  7. Order and cleanliness of the wiring

Aware of the importance of the project and its difficulties and aware of its ability to interpret the standards and its experience in the creation of special test systems, SIF accepted the challenge.

Thanks to a core concept that has already applied in several systems in the fire testing sector, SIF has studied an integrated and flexible solution, not only to meet the requirements but introducing those details that make the difference, transforming a simple test equipment into an innovative test system

The system, enclosed within a single test cabin, made of AISI 304 stainless steel, alternately accommodates the two test benches composed as follows:

AIRCRAFT CABLES TEST 1:

  •  Electrical cabinet with PLC and Siemens 9" touch-screen color display with software for the control and management of resistance tests to electrical overload and cable-to-cable abrasion.
  •  Test bench equipped with wheels, on which the system for the cable-to-cable abrasion resistance test  and the system for the electrical overload resistance test are mounted. The cable-to-cable abrasion system is composed of a vibration exciter for the movement of the conductors under test, which guarantees a speed of 10 cycles per second and a movement of 6.35 mm. The overload resistance test system is composed of a wire tensioner capable of guaranteeing the mechanical tension of the sample throughout the test in which a direct current is applied to the cable under test to reach the prescribed temperatures. The black and white striped screen allows the operator to view any smoke emissions.

AIRCRAFT CABLES TEST 2

  • Electrical cabinet, with PLC and Siemens 9" touch-screen colour display on which the software for the control and management of dry and wet arc tracking resistance tests is installed, with special thermal switches prescribed by the standard for the detection of the short circuit.
  • Three-phase 400Hz 200V voltage supplier.
  • Test bench equipped with wheels, on which the system for the test of resistance to dry and wet arc tracking are mounted. The dry arcing resistance test system consists of a VIBRATION EXCITER for the movement of the blade, prescribed by the standard, which guarantees a displacement of 5.5 ± 0.5 mm at a speed of 30 cycles per second. The wet arc tracking test equipment is in turn composed of an adjustable electrolytic solution dispensing system. Both bench mounted test systems can take advantage of the quick terminal block for electrical connection of the specimens. The standard also prescribes, before carrying out the test, the verification of the operation of the 6 thermal protection switches. For this reason, an automatic system has been designed to detect the tripping time of each circuit-breaker, drastically reducing verification times.

All test systems are equipped with instruments that allow you to verify and demonstrate the conformity of the test and in addition to this, there are various tools included in the supply that facilitate the preparation of specimens and test systems, thus speeding up the procedures.

A supervisor software which communicates with the PLCs of the equipment allows the acquisition of test data through a selection menu for each type of test. The software can then automatically generate at the end of the test a .csv file from which an editable report in Word format with template and company logo is taken, containing the test data and spaces available to integrate with any notes, so as to obtain a true and detailed report. Furthermore, in the dry and wet arc tracking tests, the camera shots are integrated, saved in the relative folders. Even the tests for verifying the operation of the thermal switches can be saved in an Excel file to create a detailed archive. Thanks to this software that can be connected to the company network, the system meets the requirements of INDUSTRY 4.0, allowing access to the provided benefits.

Finally, three of the four tests have rather long durations and require the intervention of an operator at specific times provided for by the Standards. To facilitate the operator's task and allow him to act promptly, relay outputs have been provided to communicate remotely to the operator that an event has occurred. To make these warnings more specific and effective, SIF has developed an optional system, which communicates events by transmitting a screenshot of the status of the test in progress directly to a company chat via the "Telegram" APP. With this innovation it is possible to create a group on Telegram and add all the operators who need to receive these messages.