Product category:
Electrical and Electronic Testing
News Release from: Clare Instruments | Subject: Electrical safety testing
Edited by the Manufacturingtalk Editorial
Team on 22 November 2006
Traceability the key to effective safety
testing
Integration and automation have become key factors in the development of modern production line electrical safety testing systems.
Integration and automation have become key factors in the development of modern production line electrical safety testing systems Now another feature is growing in significance in the form of test data traceability, claims John Barnett of test instrument and systems manufacturer Clare Instruments
This article was originally published on Manufacturingtalk on 10 Aug 2007 at 8.00am (UK)
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In recent years, manufacturers of electrical products and components have become increasingly aware that the implications of electrical safety testing go much further than the design and development stages.
The need for electrical safety testing is dictated by strict safety requirements and manufacturers' liability in relation to various technical standards and these responsibilities extend to the end of the production line.
These factors, together with growing awareness of the role of electrical/electronic safety testing in maintaining product quality, have contributed to the trend that has seen 100% production line testing replace batch testing or sampling as the favoured best practice among many manufacturers.
Further reading
Ruggedised cable and wiring harness tester
The latest addition to the Clare range of electrical safety testing equipment for manufacturing and service engineers is a special ruggedised cable and wiring harness tester.
Test enclosures and fixtures set standards
Production line electrical safety testing specialists Clare Instruments has launched a range of test enclosures and fixtures.
High-speed production electrical safety testing
Clare Instruments has introduced new test instrumentation designed specifically for the high-speed electrical safety testing of large volume throughputs on the production line.
As a result, the verification of functionality and the safe operation of electrical products is now recognised as absolutely vital and production line safety testing has become an essential part of the appliance manufacturing process.
In response to this situation, manufacturers of electrical safety testing systems have developed a comprehensive range of test equipment suitable for use as individual instruments in product development or quality control laboratories or as integrated, semi or fully automatic test stations used on the production line.
Invariably the manufacturing process for many electrical or electronic equipment, components or assemblies involves a variety of tests, the full extent of which depends on the complexity of the end product.
Given the tremendous variety in size, shape and performance characteristics of the wide range of appliances and equipment now manufactured, it is often the case that customised electrical safety testing solutions need to be developed to meet specific production line requirements.
This requirement has led to the development of more sophisticated electrical safety test equipment such as Clare Instruments' HAL flash tester and the G106 production line tester.
These test instruments are capable of being easily pre-programmed with different test sequences to meet different test requirements thus covering a wider range of product types.
The modular design of the electrical test instrumentation itself allows specific test station configurations to be developed quickly and effectively.
The use of specially designed enclosures and test fixtures with customised contact points or adaptor units, interfaced with the test instruments, means that fully integrated stations can be developed for virtually all electrical products, whatever their geometry or surface finish.
The increased onus on 100% testing invariably requires the testing stages to be undertaken as an integral part of the production line.
In the manufacturing environment, time is money and the justification for the incorporation of test stations is rarely made on technical grounds alone.
In this respect the time taken for completion of the test cycle is critical - enforcing just in time manufacturing with unit production times of 5 minutes is clearly of little value if the end of line test station takes 10 minutes to complete all tests.
In response, both analogue and microprocessor controlled test systems are now available which are capable of applying typical earth ground, hi pot and insulation resistance safety tests in timescales as fast as 2-3 seconds per product.
In addition, as a means of streamlining test stations and matching productivity rates, specially designed holders or jigs allow the testing of multiple products at the same time.
Automatic or semi-automatic electrical safety testing also reduces the reliance on manual procedures, further speeding the test process.
Although testing should always be undertaken by competent staff, in many cases the use of pre-set test parameters, protected by key operated switches and/or failsafe devices, means that the use of highly skilled or experienced test staff may not always be a pre-requisite, allowing greater flexibility in the use of production or assembly line personnel.
Alongside these technical and manufacturing process considerations lie the quality control factors that have placed greater emphasis on the importance of 100% test routines as a safeguard against any product liability problems.
Efficient production line test procedures can eliminate potential re-call costs, re-working costs, lost production and late delivery problems which can all be associated with alternative batch sampling routines.
It is also the modern demands of quality control that are now placing greater importance in a relatively new area of electrical safety testing, automatic traceability of test results.
Knowing why safety tests are necessary and integrating them with the production line is one thing, but being able to prove a product's compliance is another matter - particularly in the subsequent event of a failure or accident in the marketplace.
The only way to prove that an appliance or item has been tested properly is through documentation.
With conventional manual recording systems being fraught with potential errors and problems, the most effective way to prove compliance with relevant standards is to use test instrumentation that not only automates the test process but is also capable of recording the results at the same time.
This has led to the development of test instrumentation incorporating memory for storing test results and the capability of communicating with printers directly and/or PC programs.
As well as storing results for later printout or downloading to a PC, such systems can be combined with pass/fail label printers complete with serial numbers and/or linked to bar code identification.
In addition, networking with central management information systems can allow the test station to become an important data collection point, not only in identifying failure rates, but also providing details of productivity levels and other information as part of quality audit trails.
Some systems like Clare Instruments G106 production test system use a PC program to create test routines that are then transferred to the test unit.
If the test station is on-line i.e connected to the PC then the database will be automatically updated with test details while production testing is under way - thus ensuring automatic traceability of test details without interfering in any way with the test process or introducing additional work procedures.
If documentation is required to be shipped with the product then automatic print out directly from the test unit after test is also possible.
Other possibilities are data capture to PC software on a periodic basis say weekly or monthly depending on production test throughput.
Here the test data is retained in memory then on a regular basis downloaded to the database.
Various reports can be produced from this data but the database itself provides the necessary traceabilty.
There is also evidence that the costs of warranty claims can also be reduced significantly by linking 100% production line testing with full traceability.
In the appliance manufacturing industry, for example, there are examples of warranty costs being reduced by 90% with introduction of an integrated fully traceable safety testing system.
In this way, proper documentation generated automatically by the test instrumentation minimizes product liability and provides effective proof that a product is safe at the end of the manufacturing process - when product integrity and customer safety are the issues only 100% testing and traceability can show 100% conformance. Request a free brochure from Clare Instruments ...
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