In commercial wire products, performance and safety specs are a big deal and meeting the requirements as a manufacturer is important to product longevity. One of the main ways to ensure custom wire harness products are in perfect working order before they leave the facility is to test them against known limits electrically. Certified components in the North American commercial electrical industry all have performance and safety specification documents that must be met when using them on certified products.
Physical Charcteristics
Physical measurement specs are tested against and are performed using high accuracy tools to measure crimp heights, conductor thicknesses, insulation thicknesses and other physical aspects of a wire harness like lengths, pitching, tie down spacing for example.
Electrical Characteristics
Electrical characteristics pose a unique set of issues when dealing with wire quality. They require a device capable of measuring more than just whether or not a small signal voltage passes through a circuit. Especially in low voltage data circuits, small discrepancies in resistance values can cripple digital sensing systems that require tight control of a circuit. As more delicate and complex digital robotic circuits become popular and standard, noise shielding failures can cause sensitive data circuits to be inaccurate resulting in machine failures and miscommunications. Cirrus testers can test these sensitive values repeatedly during assembly to maintain circuit integrity to a high degree.
At C-T Wire Prep Inc. Cirris Harness Testers are the gold standard for maintaining high quality products in every custom harness product line. They have been the industry standard for advanced wiring applications in the aviation, medical and military industry since 1984 to ensure critical operations.
Cirris Testers use multiple simultaneous test measurements connected to a live test jig during the assembly process to test every important characteristic of the harness before each custom product is shipped. A built-in audible feedback system guides the assembler through the build process notifying them of different type of errors. Once a first connection is made on the jig, an open connection process begins to make a single beeping sound. Once the harness has been fully connected, the sound changes to another different “good cable” sound signifying completion. If any errors are present, two different sounds can be triggered. A triple beep signifies to the assembler there is a wrong connection or a short circuit. A double beep signifies resistance issues. Listen to examples below:
In addition to testing continuity like a typical volt meter, Cirris testers use a point to point linking system that maps out the entire circuit including any intentionally shorted connections, any intentionally open connections, circuit wiring errors, testing against limits for resistances, and HIPOT high voltage testing.
Let’s look closer at each characteristic below.
Circuit Continuity – In order to ensure that each wire carrying electricity does so effectively is number one for harness quality. Continuity testing guarantees that there are no breaks in the copper wire inside the insulation, and that electrical current can pass through every single connection terminal attached to the wires.
Voltage Drops – Digital testing capabilities allow us to repeatedly scan a circuit with test voltages in sequences to see if any power is being lost through the harness. This test is very closely related to the next point
Max. Resistance Limits – Harness testing devices use a combination of an applied signal voltage to the harness, plus a live measurement of the resistance values with set limits to test for circuit viability through the harness. If resistance increases with load the tester will signify an error and show how much resistance is being created. This test guarantees that bad crimps do not make it into the final assembly.
Short Circuits – Shorts in electrical systems are to be avoided at all costs unless intentionally in the electrical design to complete a task like creating a loop, or switching. During assembly, the Cirris tester is scanning every programmed connection point at a rate of 256 connections per .33 seconds. Short circuits are differentiated from open circuits on the digital readout of the tester to help the user find errors.
Intentionally Shorted Connections – A feature made available by combining assembly jigs with integrated harness testing, each individual circuit end is separated inside the tester unit. When a harness is programmed (“learned”) and stored by the tester, each connection is tested to see if they are intentionally shorted, open or closed. If a circuit is any of the three, the tester looks for that characteristic in every harness thereafter.
Miswiring – Harness testers let the assembler know in real-time when they have made a wiring mistake.
Hipot Voltage Testing – Once a harness is fully attached to the test jig and is verified to be fully operational by the cirrus tester, an additional test can be performed by sending a high voltage through the wire harness to stress test it before the final “good cable” completion result. This ensures that when a client plugs our product in for the first time and turns on the power, there will be no faults in real world use.
When designing a test jig with an integrated circuit test, the digital tester interface must define the physical pins and store their corresponding connections to one or more other pins to test against. Once mapped, a program of the sample unit is stored and saved for recall ensuring that future runs of the same product are equal in quality and function.
When an error presents during assembly, quality assurance techs can easily find which component on the harness is failing by analyzing the readout and physically locating the affected connections.
When paired with a robust quality assurance program that includes first-off checks, technical data analyzation and application, visual checks and employee training, harness testing seals the deal by guaranteeing functionality.
I hope you have found this information useful in determining viable high quality wire harness solutions.