End-of-Line Test Cell
CTMC Test Cell to Optimise End-of-Line Tests
Project details
With over a century of experience, Lucy Electric is a global leader in power distribution solutions, specialising in electrical distribution products, automation systems and monitoring systems. Lucy Electric serves various sectors such as utilities, industrial, commercial, and infrastructure, providing reliable and innovative solutions that enable efficient and sustainable power distribution. The company is committed to driving digital transformation in the energy sector, ensuring reliable power supply, improving operational efficiency, and facilitating the integration of renewable energy sources.
A particular Lucy Electric product range are their CTMC (Current Transformer Metering Chamber) units. These CTMC units provide a convenient, reliable and robust means of distributing electrical power within buildings, and provide a means of connecting metering equipment to allow measurement of energy usage. They also integrate fuses to stop the flow of current in response to an over-current event.
Project challenge
Avazia were approached by Lucy Electric in order to improve the end-of-line testing of their CTMC units, in terms of efficiency, accuracy and result recording. The main challenges is that faced Avazia were as follows:
- The CTMC units need a wide variety of tests performing on them, which requires a variety of test instruments
- Historically, most test instruments used were hand-held and had very little capability in terms of automation or result recording
- The range of CTMC units which Lucy Electric produces is wide, and tests vary widely depending on which variant of the CTMC is under test
- High-voltage test sources used for insulation resistance measurements present a hazard
During the testing of the CTMC units, these hand-held meters and probes would be used following a test procedure on paper and the results would be read and written down manually. This, in some instances, was a time-expensive procedure, and added the possibility of introducing human error. The possibility of errors occurring was also not helped when taking into account the large amount of CTMC variants, and the need to have written test procedures which allowed for all of the variations.
Project solution
The solution was for Avazia to develop the CTMC End-of-Line Test Cell.
The test cell is a room-sized test environment which focused on alleviating the drawbacks of the previous approach to testing the CTMC units, whilst also improving fundamentals such as safety, lighting, storage and workspace.
The test cell replaces all previous hand-held meters and probes with rack-mounted instrumentation which has communication with a rack-mounted PC. This allows for the Avazia-developed custom test software to control the configuration of the instruments and also to read test results and data back from them.
The custom test software interacts with and guides the test operator through a test procedure which is specific to the variant of CTMC being tested using a touch-screen monitor. It shows useful images at key steps through the procedure to indicate exactly to the operator what elements of the CTMC they should be testing. An additional feature is that Lucy Electric can create their own CTMC variant profiles within the software in order to allow for expansion to the CTMC range.
Although probes are still manually applied to the CTMC by the operator, the probes to be used are highlighted to the operator using LED indicators and fail-safes are applied in the instance the operator picks the wrong probes. Once probes are applied to the CTMC UUT (Unit Under Test), the measurement is taken and recorded automatically by the software and stored in a database.
In terms of high-voltage safety, Avazia used applicable and relevant safety standards to develop an integrated safety control system which uses light curtains to prevent high-voltage discharge in the event of unauthorised access to the test cell. The safety system also comprises of two-hand controls which means that the operator is unable to have any contact with the CTMC UUT whilst high-voltage is applied to it. It also incorporates emergency stop switches and appropriate indicators to inform personnel of the status of the system.
The test cell has improved not only recording the results of CTMC units which pass testing, but also recording of test results from CTMC units which fail and the reasons for the failure, providing full traceability for later analysis by quality control personnel.
The test cell was fully installed and commissioned by Avazia, with detailed training provided. It has now been operating seamlessly since 2022 and has improved test cycle time significantly whilst also improving quality control markedly.
