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Jan/Feb, 2024


Insourcing Cable Manufacturing and Testing: Part 2


By James Louw, EVCables.com E


V charging cables pose a unique risk in that the safety systems are inbuilt into the cable which prevent over current


conditions during charging. This is handled through a coding resistor embedded in each plug that tells both the EVSE (Electric vehi- cle supply equipment) and EV (Electric vehi- cle) the maximum current capability of each cable conductor. It is therefore paramount that these


resistors are correct and inspected in every cable made. The CableEye unit not only


opment and feed these valuable test results back to component suppliers to accelerate designs and reduce time to market; all this even before the J3400 has been published.


4-Wire Kelvin Testing EVCables.com sees itself as a bespoke


manufacturer, spearheading a Made To Order approach with next day fulfillment for all sales from its online store. It does not run any series production of any of its lines and thus does not hold stock of any length of pre- built cable. It has a unique challenge to overcome,


Wottz NACS connector.


allows one to inspect these resistors but com- pares them against tolerances defined in the relevant standard IEC 61851.


Rapid Prototyping The EV charging landscape is ever


changing and EVCables.com aims to supply its customers with current and future charg- ing solutions. NACS (North American Charging Standard) is the future of EV charging in North America. It is a standard that has yet to be ratified by SAE. EVCables.com was able to not only


develop working prototypes of future connec- tors but also create relevant test suites that can evaluate the performance of connectors and electrical contacts that are still in devel-


which is ensuring that the cable shipped to the customer is of the correct length within 5% cutting tolerance. When every cable made is a different length to the previous cable EVCables.com required a robust way of detecting a cable of incorrect length. This is where the CableEye 4-wire Kelvin testing at 1A differentiates itself from the competition. With a sensitivity of one milliohm, the CableEye system provides the ability to detect vary- ing cable lengths even with a con- ductor core area of 6 square mil- limeters. With tests preloaded with val-


300 200 100


ues that it has learned from many thousands of cables manufactured, EVCables.com can detect a cable that is too long/short from what a customer ordered. The 4-wire Kelvin testing also gives the ability to detect crimp failures, whether that be a crimp onto insulation or detecting a crimp failure due to a hydraulic crimper shearing a bolt which caused it to not reach full crimp pressure (true story). The company also used 4-wire Kelvin


0


to offer a product with confidence that is not only compliant but at the exact specification requested by the customer. Eighteen months ago, EVCables.com


engaged in a business process shift from out- sourcing to insourcing the manufacture of its EV cables. Inevitably, this required the com- pany to grow its own competency in testing cables. The first phase (ref. Part I of this arti- cle) focused on the selection and acquisition of an accurate and dependable test system capable of meeting industry-specific quality standards. Since rolling out the new test system,


the company has achieved an output of 500 cables per month, increased sales by 50% year on year, and seen a 98% decrease in


Resistance of copper conductor 6mm2


2mm2


10


20


30 Length (m)


Graph comparing different conductor resistances over length.


returns related to manufacturing defects. EVCables.com is well on the way to shipping


6,000 in 2024. Contact: CAMI Research, Inc.,


testing to detect that the correct size copper conductor was used. The sensitivity of this test is unmatched and allows EVCables.com


42 Nagog Park, Suite 115, Acton, MA 01720 % 978-266-2655 E-mail: sales@camiresearch.com Web: www.camiresearch.com r


40


50


Resistance (m)


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