issue: July 2007 APPLIANCE Magazine
Connectors & Wire Harnesses
The Critical Components
Email this Article
by Diane Ritchey, Contributing Editor
Proper connection is critical: a high-quality connector can ensure a safe appliance and a happy customer. Thankfully, the global connector industry is healthy, strong, and rich in new technologies.
The Multi Axial Rotational Connector (MARC) from Anderson Power Products is well-suited for medical applications and designed to mate while traveling through an arc with a 3-in. minimum radius. The MARC is rated to 30 A, combining power, signal, and ground circuitry into one package. Featuring eight Powerpole circuits integrated into a blind mate housing, the two-row horizontally oriented connector uses the company’s flat wiping contacts and can be configured with eight standard-length contacts or six standard-length and two premate ground contacts. The component features mechanically keyed housing to ensure proper mating and enables rotational blind mating with approximately 0.090 in. of error correction. It is rated to 10,000 mating cycles and constructed of a chemically resistant PBT plastic.
Connector manufacturer Thermtrol Corp. in North Canton, OH, U.S., has found success halfway across the world in its Vietnam facility, where crimp assembly is done and thermal protectors are produced. Thermtrol has wholly owned the facility since 2003. “It’s just as world class as China, and the ease of business is superior,” says Greg Wurgler, sales manager. “It’s easy to get materials in and out, and they have top-notch engineers, similar to China.”
Additional benefits of Thermtrol’s Vietnam investment, he says, include the fact that the U.S. dollar is a recognized second currency. English is an official second language, so contracts, even with the government, can be written in English. A “flat” government structure makes government dealings easier, creating an environment conducive to foreign direct investment. In addition, the workforce is well trained and educated, and Vietnam is currently the lowest-cost labor area in Southeast Asia that has adequate infrastructure for import and export. Wurgler adds, “In Vietnam, companies can be owned 100% from the outside. For example, in our case, our company owns 100% of our Vietnam subsidiary. This has not been the case in China.”
Mega Electronics is another example of globalizing in the connectors world. The company is supplying a major European appliance maker with power cords built in its Asian plant and drop-shipped to the Middle East for assembly.
“We had to develop a new tool to satisfy this customer,” says Guy Francfort of the company. “Our standard flat plug had a single injection mold, which the end customer felt left the consumer at risk of a wire-to-outer-contour shock. They wrote an 80-page specification for the double-molded plug, power cord, and packaging. From reading the specification—which required us to document the weight of the cardboard, packaging material, and wood content—we could see that the Europeans are far more conscientious about the recycling than any of their American counterparts. I believe that much of this is driven by the European governments and it makes one wonder—what is the cost of being green?
“The new double injection mold and molding costs more than the standard process, but our customer felt it was worth the extra expense,” Francfort adds.
V-LOCK, an IEC-Standard-C13 connector with a locking feature from Volex, prevents unnecessary disengagement of a power source.
What is behind the positive outlook for the global connector industry? One factor is demand for a higher level of demonstrated quality, says Wurgler of Thermtrol. Connector manufacturers are continually delivering connectors that go above and beyond former standards.
Such is the case with Thermtrol’s crimp cross-sectioning process, equipment that in the past has not been widely available, but ultimately is more cost effective. Thermtrol does its own cross-sectioning versus having terminal manufacturers handle it.
“It puts the quality control in our hands,” says John Komer, vice president of operations for the company.
Thermtrol’s system uses a workstation equipped to photograph the crimping to make visible all the measurements and the individual wire strands in the terminal.
“In the old days you had to look at the measurements in a microscope,” Komer says. “This system, which takes place on the production line, only takes five minutes to complete, and it’s obviously more
Special PC software is available to calibrate the crimp height, the crimp width, count of strands, and crimp area measurement, as well as the compression ratio. Cross-section images and all data can be output to a report file for a quality check.
“In the past, we measured crimp height to tell you the tool wear,” adds Chet Rojice of the company’s Wire Harness Program. “Now you continually monitor tool wear to know in advance if the tool die needs changing. It’s proactive.”
“Quality in crimping ultimately benefits the consumer,” says Wurgler. “Our decades of crimping experience of hundreds of millions of crimps, combined with output from the system, enables us to use the latest cross-section technology to its fullest effect.”
Another example of high-quality product development is from Brascabos. “The most important contribution that we at Brascabos bring to our customers is the engineering we provide in our early supply involvement stage,” says Francisco A. Fiorotto, president of the company. “By doing this we can identify the best cabling routes, the best connection and wire specification to be used, and also help the customer to improve the parts necessary to settle the harness. We develop the project considering the harness manufacturing process and the assembly process at the appliance production line, at the same time.
“After an analysis of the best route and fixation points of the harness in the appliance under development and the definition of all electrical charges and mechanical characteristics, first we look for the least expensive material the application will allow,” he tells APPLIANCE. “We only add items to our inventory when the specification of a final harness requires it.”
For appliance makers, he says, such a proactive product design process offers almost zero defects in the harness during the use of the appliance; a safer product related to electrical insulation, fire resistance, loosed connections, and complete reliability on all electrical conducting functions; an optimized assembly process of the harness, considering low-force connections used; a JIT supply-chain system for a reduction in inventory; and an optimized, lower-cost project.
The process also helps Fiorotto achieve an increase in automation that results in higher productivity and quality levels, in addition to components commonality that offers competitive materials prices. Lower administration costs also result, and the use of information technology over the supply chain administration ensures material in the right quantity at the right place at the right time.
FCI’s PV wire-to-board connector is designed to be an innovative crimp-to-wire system for connecting discrete wires to printed circuit boards. The PV receptacle system utilizes a dual-metal spring that maintains consistent contact pressure through 1000 mating cycles, and is available in different spring pressures for customized insertion and withdrawal forces. PV receptacles mate with 0.025-in. (0.634-mm) square posts and may be installed in Mini-Latch housings or used discretely.
Standards Lead the Way
Standardization and globalization are important driving forces in the appliance industry, and connectors suppliers also are driven by them. Although they are relatively new to NAFTA regions, standardized RAST IDC connectors have been used in Europe for more than 20 years and are continuously making their way to the NAFTA market.
“RAST IDC are inherently a superior termination method over crimping for smaller wire sizes [up to 16AWG], and the connectors are designed for automation,” says Rob Boyd, crimping product manager for Schleuniger Inc. “High-volume, automated processes save costs, and each harness can be run through numerous tests to ensure quality before it even leaves the machine. Therefore, the customer sees cost and quality benefits.”
Schleuniger Automation manufactures the MultiCenter 30, designed to process harnesses with RAST connectors. The MultiCenter will feed up to 36 different wires, terminate each end with either RAST 2.5, RAST 5, RAST 2.5 Power, or crimp connections and perform electrical tests on the harness before it leaves the machine. The result is a low-cost harness that has been fully tested for quality, Boyd tells APPLIANCE.
Yet, he notes, “The NAFTA appliance industry still needs to catch up. There are still many crimp termination machines in the field that customers want to utilize. The initial investments on the RAST IDC systems are quite high, so there is still some reluctance. However, we are seeing more and more inquiries. Even the automotive industry is looking at IDC terminations for some applications.”
Adds Fiorotto of Brascabos (Solartech), “RAST connections are safe, easy to mount [requires minor physical effort to do the connection], and assembly-error-free [it’s impossible to connect in the wrong position]. They do not require different colors in the cables for identification, are smaller in size, and are faster [all connections at each particular device are done in one operation], and this is ultimately what the appliance maker wants.”
Fiorotto says that his company uses RAST connectors to help fully automate the production process, which in turn requires less complexity in material administration. In addition, he says, “There are fewer wire colors, so the amount of manual labor is drastically reduced and quality is improved. The final cost of a harness made from other connections without RAST is more expensive, if one is considering the entire supply chain.”
The appliance producer, he adds, “would not notice connection differences, but they would know if their appliance fails due to a loose connection. This would not happen with RAST.”
Another supplier in favor of RAST connectors is Tyco Electronics (Harrisburg, PA, U.S.). Says Jim Connors, appliance industry manager for Tyco, “By having a thorough RAST product line that permits appliance OEMs and harness contractors to select the technology that meets their needs, we make it easier for OEMs to implement a connector design that fits their current manufacturing capability.” Yet, he notes that since RAST is not fully implemented in the Americas, having both crimp and insulate on displacement products (and tooling) provides additional options for OEMs.
Chinese RoHS Concerns
FCI (Etters, PA, U.S.), developer of connectors and interconnect systems, simplified the product selection process for customers concerned with meeting the Chinese RoHS environmental regulations. A link specific to the Chinese regulations has been added to the company’s RoHS microsite to allow customers to search by product for detailed information about each connector’s compliance with the new specifications. Information on European RoHS compliance is also available on all products.
“The move to lead-free is the most dramatic change to have occurred in the connector industry, with repercussions throughout the logistical chain, affecting all product lines and production processes,” says Jeff Toran, director, Global Engineering Services for FCI.
To assist customers in meeting their legal obligations, FCI established and continues to build an internal database from which lead-free and RoHS reporting information can be easily obtained. In this way, the supplier is able to provide its customers with ready access to detailed information on substances found in its products.
Materials used to make connectors and wire harnesses are also becoming more standardized, which could mean changes in the upcoming years. For example, because of the European Union’s (EU’s) RoHS and WEEE Directives (Restriction of Hazardous Substances/Waste Electrical and Electronic Equipment), many connector manufacturers, such as ITT Cannon, are removing lead, cadmium, mercury, hexavalent chromium, PBB, and PBDE (plastic flame retardants) from products.
Detlef Mews, owner and president of HSU Electronic Components in Pleasanton, CA, U.S., tells APPLIANCE that another key component of a harness or power cord is the electrical wires or cables, which are also seeing materials changes. “For most applications, the PVC compound is the choice to use, yet some applications require better mechanical resistance, reduced diameter, high temperature, or different chemical resistance,” he explains.
For example, he notes, with a harness in a cooking appliance that operates in high-temperature environments, the basic insulation used today is silicone with fiberglass.
“At Brascabos we are producing harnesses with wires and cables that use a different compound that results in several advantages,” explains Fiorotto, “including easily stripped and terminated wires, an elimination of a glass braid resulting in no irritating glass fiber, no glass strands to make the terminations unreliable, less stripping die wear, no braid to damage, [and] thus no lacquers to smoke, crack, or turn brown with heat aging.”
Other advantages include a significantly smaller diameter; flexibility for easier routing and possibly smaller electrodes; and superior fire resistance, thermal stability, and resistance to aging. Because it is a pure polymer, not a compound, there may be more consistent composition and performance.
“All of these advantages lead to a better-made appliance at a lower cost,” Fiorotto says.
Canfield Connector’s 5FR and 5JR series solenoid valve connectors incorporate full-wave bridge rectifiers inside fully molded connectors. Both series convert alternating current to direct current, reducing coil burnout resulting from valve sticking while eliminating the “hum” of alternating current. The low-profile “straight-line” interface-cord configuration of the 5FR and the low-profile 90° interface/cord configuration of the 5JR suit the connectors for installation in applications with space limitations. Both connectors are made from flexible polyurethane and have high-durability housings.
Simplicity in Design and Installation
“Features that help in the manufacturing of wire harnesses and installation of connectors in appliances are key,” says Connors of Tyco Electronics. “As such, there is increasing demand for connectors that are polarized and keyed so that errors in mating connectors are minimized or eliminated.”
In this component area, the appliance industry has shared common designs with the automobile industry, and that trend appears to continue, Connors adds. “Contact retention enhancements, connector locking enhancements, and moisture proofing are perennial design needs,” he adds, “but one nuance is that the features and benefits of automotive style interconnects [made with appliance market materials and performance requirements] are finding applications in the appliance industry.”
For example, Tyco’s 350 A Power Series connector has the highest current rating in the company’s new product line and is rated for 222 A at 600 V (ac or dc) when using 300MCM wire and demonstrating a 30°C temperature rise. The connector employs a genderless housing design that allows mating between two identical connector housings so only one housing part number is necessary. The contact system also minimizes part count and uses one contact style. A housing suitable for industrial environments protects the contacts, which are suitable for repeated mating cycles.
The Cm3 connector from ITT for small and medium servomotors has simplified internal wiring and replaces two bulkier conventional circular connectors, reducing mating to servomotors to four steps. The connector has a low profile that is ideal for space-sensitive applications and a lower installation cost, and it is said to be 50% smaller and lighter than conventional circular connector designs.
Mews of HSU Electronic Components tells APPLIANCE that the company’s power entry box model AK is an example of innovation in simplicity. The product is an all-in-one model that combines a terminal block with a power distribution device with an integral strain relief device for the incoming power cord. The product can be prefitted at the wiring harness provider with line and load wiring, jumpers as needed for various power distribution requirements, or a condenser/filter if required. “AK is snap-fitted,” Mews says, “no tools are required to install it, and it is held securely in place by a tamper-proof lid that can be opened for service [for example, to replace the power cord if that is ever needed].”
Designed for global markets, HSU’s power entry boxes carry multi-agency approvals for use in domestic and international applications, Mews says. “They greatly simplify inventory requirements, while at the same time make installation a snap—thanks to their snap-fitted mounting base.”
Another connector making inroads is the company’s Z-GK series strain relief with integral clip-on terminal block. The Z-GK can be used as a stand-alone strain relief device or as a terminal block with up to six poles that can be clipped on by means of a dove-tailed slide-in-channel for terminating line and load power wires. An optional grounding clip provides protective earth right at the point of power entry. Z-GK is rated up to 30 A.
“Thanks to dual slide-in-channels, the terminal block part can be oriented either perpendicular or parallel to the enclosure/bulkhead wall,” Mews tells APPLIANCE. “For the Z-GK, the same applies as for the power entry boxes: Z-GK greatly simplifies inventory requirements,” he says, and the snap-fitted mounting base facilitates installation. “A manufacturer can choose to use the strain-relief device or the combo feature for an all-in-one setup.”
Etco’s Flat-Snap electronic connection makes it possible to connect wires with one quick snap. Assemblers simply overlay the two unisex connectors and pull them together until they snap securely into each other. They can be disconnected by reversing the motion.
Changing out electronic components can often be time-consuming, with the cutting of wires and re-crimping, according to Etco. Manufacturers can now save time and money on electronic connection changes by using Flat-Snap on original installations. Its flexible design can be customized and insulated.
“Flat-Snap’s most important feature is that it allows for easy assembly and disassembly,” says John Macaluso, vice president of marketing for Etco. “Most terminals are industrial, standard ‘push-on’ connections, and we wanted to find a way to break the mold. Our new Flat-Snap is a ‘pull-on’ connection that will not come apart accidentally but can be easily pushed apart.”
3M recently added a new no-polish connector to its fiber connector family, enabling fast, on-site installation of single-mode and multimode connections. The 3M no-polish connector utilizes a one-piece, pre-assembled design, eliminating field polishing and loose parts.
With the factory-polished ferrule assembly and a mechanical splice, the 3M no-polish connector can be installed quickly, without electrical power, and using a simple tool, resulting in little setup time or capital investment. A bell-shaped boot is permanently attached to the connector body so there is no chance of losing it or forgetting to install it before inserting the fiber. The bell feature maintains the minimum fiber bend radius for excellent strain relief. A connector installation can be completed in less than two minutes, says the company.
|Suppliers mentioned in this article: