Transcription of www.kts-cable.com
1 PAGE 4 COPYRIGHT 2002 DANIELS MANUFACTURING CORP., ORLANDO, FL PHONE 407-855-6161 FAX 407-855-6884 E-MAIL: TTS Systems CD Pages 1/14/03 2:47 PM Page 4 PAGE 5 COPYRIGHT 2002 DANIELS MANUFACTURING CORP., ORLANDO, FL PHONE 407-855-6161 FAX 407-855-6884 E-MAIL: TTS Systems CD Pages 1/14/03 2:47 PM Page 5 Alphatron TTS Systems CD Pages 1/14/03 2:47 PM Page 6 There are several steps in the process ofterminating wires that must be followed in order toassure quality and longevity in the service life of awire harness.
2 These include compliance with engi-neering and customer requirements , maintenanceand gaging/inspection of crimping tools, dies, appli-cators, and presses. If the termination is beingmade by ultrasonic welding, there are calibrationand verification measures that must be followed. Crimp height and crimp pressure measurementsmay indicate a condition that requires further atten-tion, but when all is said and done, the tensilestrength of a crimped connection is the final answerwhen a pass/fail decision is on the table.
3 A good connection starts with the correct selec-tion of wire, contacts, terminals, or other crimp tool, or press, and the correct accessory(die, locator, applicator, etc) should meet all thespecified go/no-go gaging requirements . Operatorabilities and safety must always be consideredwhen selecting a certain tool (or press) for thevolume and size work that is being HEIGHTis a valuable data point in theoverall wire harness quality assurance process, butit should not be relied upon as the ultimate pass/failcriteria.
4 The measured height of a crimped or weldedconnection may verify that it was crimped in the cor-rect die cavity and the minimum pressure wasachieved, but it will not reveal a more illusive defect;like broken strands, failure to remove the wire insu-lation properly, cracked or fractured metal or severalother possible problems. Since crimp height is anon-destructive test, and it is relatively simple toperform, it should be considered as a component ofmost wire harness quality assurance PRESSUREis another good indicator ofthe performance of the operator and the equipmentin the wire harness fabrication process, however,the crimp pressure monitor (sometimes called crimpquality monitor) is available on relatively few pressesand no hand tools that are utilized in the NorthAmerican wire harness industry.
5 Where they areused, they produce another good data point, butoverall, pressure monitors are not commonplace,and may not be cost effective in a small or mediumwire harness TESTINGto the minimum tensile value, orto the breaking strength of a terminated wire samplewill resolve all concerns about the mechanicalproperties of the crimped or welded termination,and it will indicate,with reliable accu-racy, the electricalintegrity of a con-nection. So, whatfactors should beconsidered whenselecting a pulltester, and decid-ing how often it willbe used?
6 FREQUENCY isthe most com-monly asked ques-tion. How often dowe pull test a termi-nated wire sam-ple? Of course, theanswer will differfrom one companyto the next, andsometimes will varywith type of job or customer. TheBy Dave Kelly, Standards and Industry Liaison, Daniels Manufacturing Corporation, Orlando, Florida (USA)June 2003 Pull TestingTHE FINAL ANSWERPullTestingBro 9/8/03 5:20 PM Page 1 PULL TESTING, THE FINAL ANSWER2critical questions are usually the following:1. Are there any specific pull test requirementsin the contract or customer process docu-mentation?
7 If the harness is being made for anautomotive or aerospace application, it is likelythat pull test requirements are called-out in thecontract or referenced process for industrial and appliance applica-tions are also candidates for the contract/process pull test Are there any industry specifications thatapply to the inspection and acceptancetesting of this harness (or the equipment towhich it applies)?In most commercial and automotive applications the UL486 AStandard will apply.
8 In aircraft/aerospaceapplications the terminal specification (SAE/AS7928), the contact specification (MIL-C-39029), or NASA STD What are the manufacturers recommen-dations?Usually the manufacturer of the con-nector, contact, terminal, wire or terminatingequipment will not specify the level of inspec-tion and pull test requirements in their literature,but if you are looking for guidance, don t over-look this valuable What is my experience with this particular(or this type of) wire termination?
9 Is the wiretermination user-friendly? Is the terminationequipment reliable, or does it have user adjust-ments that must be maintained? Have I previ-ously had failures on this termination?5. Will acquiring test data on this terminationimprove my quality program?The reasonsome tests are performed is to gather uniformdata that may (or may not) be useful How critical is the end use of this wireharness?Another judgement call. If it will beused in an engine harness, a higher level ofquality assurance is needed.
10 If it connects anengine to an electronic tester, maybe that isn tas What is the cost of testing, verses the costof making a mistake?The highest possiblecost to your company is reworking harnessesthat have been returned (or rejected in-house).The most valuable asset that your companyhas is the relationship and reputation with itscustomers. A sensible pull test inspection pro-gram can be the difference between a good ora bad experience when it comes to designing,building, and supporting the wire harness pro-duction operations in your company.
