Cord Sets and Power Safety
The Forgotten Necessity

by Peter Simmons, Assistant Editor

While it may rely on outside influences to initiate change in products and materials, the cords and cord sets industry still has to provide those products at a competitive cost.

Cords and cord sets have been referred to as the forgotten component by some, but they certainly have something that other high-profile trends may not, which is staying power. That is a result of the fact that appliances could not function without cords - something that no one has been able to bypass.

It makes sense that any advancements are driven by what appliance OEMs are doing with their products, instead of supplier innovations driving OEM advancements. And what an appliance OEM wants seems to vary depending on the supplier with whom it is conducting business.

According to cords and cord sets manufacturer Unicable, Inc. (Bowling Green, KY, U.S.), what the OEMs want in general has to do less with large technical breakthroughs and more with small details. "OEMs are adding value-added steps," says Larry Oden, senior engineer for the company. These value-added processes include internal wiring assemblies, labels/warning tags, molded and mechanical strain reliefs, and grommets. "We see more cases of the OEM bringing the power supply cord further into the appliance by integrating internal wiring assemblies," adds Mr. Oden. "This reduces the total number of component part numbers in production and improves the assembly process."

According to Unicable, Inc. (Bowling Green, KY, U.S.), these transparent color cords allow connection verification through a transparent outer jacket while the colors provide a decorative touch for specialty applications. The cords can be fitted with any of the company's plug types and the jackets are made of high-quality PVC with a temperature rating of 105ûC.

Other than customer requests, many of the changes in the cords and cord sets industry come about due to the actions of governing bodies. A current example of this is California's (U.S.) Proposition 65, which is also known as The Safe Drinking Water and Toxic Enforcement Act. Part of this proposition reportedly imposes a limit of 300 ppm for lead in products.

According to Guy Francfort, vice president, Sales and Marketing for MEGA Electronics, Inc (New Brunswick, NJ, U.S.), the lead content of cords is currently in the range of 1,000 to 1,500 ppm. "It will be extremely costly for manufacturers to have separate manufacturing procedures to meet Prop. 65," says Mr. Francfort. Instead of manufacturing one type of cord for California and another type for the rest of the U.S., cord manufacturers will most likely change all production to the new standard. "This will definitely cause a short-term increase in the cost of manufacturing processes," says Mr. Francfort.

Many aspects of cords are application specific. "Most of the durability issues are driven by the customer's applications," says Mr. Francfort.

Mr. Robinson of Bergquist Company says that many companies are asking for oil- and water-resistant cordage. These cords even have water-resistant plugs. As a result of the demand, he says, suppliers are offering rubber oil-/water-resistant cordage as part of their standard material. "They're not just making plain SJT anymore," says Mr. Robinson. "They make SJTOW, because that is the compound they get in." Using the water-resistant material as a standard allows companies to carry a smaller number of cord types.

Mr. Robinson believes that while oil-/water-resistant materials are used for safety considerations by OEMs, for the cord manufacturer, it's about saving money. Since there is such a demand for a specific type of cord, it is less expensive for the cord manufacturer to use it as a standard because it doesn't have to produce two different types of cords at more cost.

In addition, says Karsten Loehken, product specialist, Networking Products/Industrial Ethernet for Lumberg, Inc. (Midlothian, VA, U.S.), cords have to be able to cover more flex cycles than before. "Downtimes are one of the most important issues in today's highly automated manufacturing," he says. "Therefore, failures such as broken cables have to be minimized." To improve flex cycles, Lumberg, Inc. uses special structures, such as finely stranded conductors. Mr. Loehken reports that another application-specific characteristic of cords has to do with the food and beverage industry.

Due to the necessity of having clean equipment to avoid bacteria, appliances in the food and beverage industry are subject to washing by a cleanser such as alkaline bleach or hydrogen peroxide (used in Germany). Therefore, cords used in food and beverage appliances have to be resistant to such chemicals. Mr. Loehken says the level of protection needed in the food and beverage industry requires a protection degree of IP69K, PVC cable, and stainless steel components.

International Issues

Manufacturing to meet international specifications is one of the biggest influences that affects the production of cords and cord sets. Cords are universal, but that characteristic brings with it many difficulties for the world's cord and cord set suppliers. The problem is that the configurations of cords and plugs used in different countries are not universal. This leads to the continuing issue of global standardization, which most companies agree will probably never be solved.

According to the Bergquist Company (Chanhassen, MN, U.S.), these cords for medical equipment and computers are subjected to hi-pot, temperature, and flex tests in the factory while the company plans for an in-house UL testing facility.

"It costs the suppliers money not to have standardization," says Jeff DeLoughery, director of Business and Logistics for Volex, Inc. (Indianapolis, IN, U.S.).

"There are specialized molds and cords for almost every country." Mr. Francfort of MEGA Electronics, Inc adds that the number of standards and codes is likely to increase. "Unfortunately, the move toward global standardization is not going in a positive direction," he says. "More countries are changing their standards and forcing manufacturers to comply with the changes."

Argentina, China, and Korea have implemented their own cord and plug standards, and Brazil is reportedly looking into doing the same. According to Mr. Francfort, China's new CCC approval standard for power cords will be required as of Aug. 1, 2003. This trend increases the number of approval marks that cord set suppliers must carry to sell their products in those areas.

Offshore Manufacturing

For U.S.-based suppliers, the most noticeable change in cords and cord sets has been the trend towards offshore manufacturing. According to Mike Smalley, vice president of Electric Cord Sets, Inc. (ECS) (Lakewood, OH, U.S.), all but a small percentage of cord and cord set manufacturing has moved offshore in the last several years. "Since December of last year, several large manufacturers closed completely, and there are more closings on the horizon," says Mr. Smalley.

Offshore manufacturing continues for the most part because parts produced can be obtained at low cost to the appliance OEM "The industry is price competitive and cords have become a commodity item," says Mr. DeLoughery. As with trends in OEM-requested items, opinions on offshore manufacturing can differ greatly.

"Electric Cord Sets was fortunate to have made strong offshore relationships early on that have enabled us to remain a viable source in the U.S. market," says Mr. Smalley. "We are approximately 80-percent offshore and 20-percent domestic in our production capacities."

The company's remaining domestic capacity allows it to provide shorter lead times on smaller orders, while providing a backup source in case of difficulties with offshore production.

While ECS remains active as an importer for the U.S. market, Mr. Smalley notes that the availability of goods from offshore sources is not always guaranteed. "We saw a good example of this last fall with the West Coast dockworkers' strike," he explains. "This year, the SARS epidemic gave rise to concerns that goods coming from the Far East might be delayed, or halted altogether."

Mr. Smalley adds that ECS feels that its domestic production capacity provides a level of comfort to its customers, who are concerned about such issues.

According to Mr. DeLoughery of Volex, Inc., offshore manufacturing is driving down prices and making it difficult for U.S.-based companies to remain viable. He says that contracts are obtained through e-bids or silent auctions and appliance OEMs announce the requirements for a contract and take the lowest bidder. "Asian companies are bidding down the cost of cords," he continues. He asserts that many companies with winning bids do not provide product that meets regulatory approvals.

Another issue involved with the offshore manufacturing debate is quality control. There has been talk that there are products in the appliance industry that misrepresent the approval marks of quality control bodies.

Mr. Robinson of Bergquist Company agrees that he has heard rumors of companies misrepresenting their approval status. "What you're looking at is a company that says it has approvals for something and puts a label on it - or just a number on the plug or the cord itself - that says it is UL or CSA approved," he says. Yet, he does not think that inferior products are a problem for Bergquist Company. "We've got a pretty aggressive quality control system, and if anything doesn't come in labeled correctly, it goes back to where it came from - or it gets scrapped," he says.

Mr. DeLoughery of Volex, Inc. adds he has seen products using straight plug blades that will not stay in the plug mold and companies that do not meet UL requirements for lay length in cords. This becomes a major issue in floor care products, power tools, and other products where flexibility is an issue. He uses these as examples of companies cutting corners in order to cut costs.

For Volex, Inc., the supplier has become the quality control police. "The majority of OEMs don't do enough testing and research related to regulatory compliance because economics do not allow for testing facilities," Mr. DeLoughery says.

MEGA Electronics, Inc (New Brunswick, NJ, U.S.) offers twist-lock plugs, which include the L5/15P, L5/20P, and L6/30P. The company reports that it is seeing more demand for twist-lock plugs - often used in industrial applications - from OEMs in the electronics and computer markets.

Unexpected Wear Leads to Heavy-Duty Solution

Vesture Corporation (Asheboro, NC, U.S.) had been producing its Vest 200 Quick Heat, a warming bag used for pizza delivery, for close to

1 year when the company realized that something out of the ordinary was occurring. The company began to notice that its customers - some of the largest pizza chains in the U.S. - were contacting it for cord replacement for the Quick Heat more frequently than originally anticipated.

"Some of the cords were only lasting a few weeks," says Stewart Glenn, director of Quality Assurance for Vesture. According to Mr. Glenn, the power cords are subjected to an extraordinary amount of wear through normal usage. "In the normal operation of a warming bag, the cord is plugged in and unplugged with great frequency," he says. "Then, of course, there are the incidental snags and pulls, as well."

The company decided that cord replacements every 2 weeks were unacceptable, and began contacting cord suppliers for possible solutions. Because Vesture had had dealings with it in the past, one of the companies contacted was Unicable, Inc. (Bowling Green, KY, U.S.).

After examining the causes of wear on the power cords for the Quick Heat, Vesture created a special test to measure how well each cord would stand up to repeated actions. According to Mr. Glenn, each cord was subjected to a series of repeated pulls at a 45-degree angle. After several rounds of testing and failed products, Vesture began to work with the engineering department at Unicable, Inc..

"We developed a new concept to improve the durability of the cord," says Helga Mayer, vice president of Customer Services for Unicable, Inc. "The design included heavy-duty molding of the polycarbonate IEC connector body with a handgrip and adding protective sleeving over the cable jacket." The heavy-duty molding is made of PVC, and the protective sleeving over the cable jacket is made of polyester. According to Mr. Glenn, the Unicable, Inc. solution was subjected to a pull test more than 2,000 times without failing.

The new, improved version of the Quick Heat was released in the fall of 2002, and close to 60,000 existing units required retrofitting. Mr. Glenn reports that the new cable is meeting expectations.

Compared to the previous cord for the Vest 200 Quick Heat, a new cord from Unicable, Inc. has a heavy-duty PVC connector body and protective polyester sleeving over the cable jacket.