Assembly in Action: Nuts Help Attach Power-Cable Termination
According to Cableco Technologies Corp. (Dublin, CA), the need to specify and use larger wires can be bypassed by using its FusionLug power-cable termination. The product delivers a current rating equal to the size of the wire. For attaching the termination to the board, a customized version of FusionLug comes complete with two steel nuts already installed. The fasteners are PEM (Type S) self-clinching nuts from PEM Fastening Systems (Danboro, PA). Among other benefits, the nuts reduce the amount of mounting hardware needed to connect the power supply to the board.
This custom system features FusionLugs on two cables. Each conducts 5 volts of power at 60 amps. Cableco fabricates the product from the stranded ends of the cable wire, which allows for multiple wire terminations. More than 100 wires can be terminated together in any one application.
"We’ve documented a 25 percent lower voltage drop with FusionLug termination compared with the stand-ard crimp lug method," says Chip Bronk, director of product development. "And, most important to our customer in this case, the termination rating equals the cable current rating."
Several stages are involved in the assembly of the FusionLug line of termination products. First, insulation from a power cable is stripped off. All the wires are placed inside a copper tube, which is compressed under high pressure. From this, a virtually solid piece of copper is formed. The end is cut off, and holes are punched for hardware. The finished product is then solder-dipped for plating.
The end-result is a termination product that is rugged, machinable and formable. It can also be customized (with chamfers, diagonal cuts and bends) per application requirements. A "boot" is molded to fully insulate the metal.
By specifying and installing the self-clinching nuts in the FusionLug assembly, Bronk finds that "attachment is quicker and easier for our customers."
In the latest application, two steel PEM (Type S) self-clinching nuts are installed permanently in each FusionLug by inserting the nuts into pre-drilled, 5.4-millimeter holes. A squeezing force is applied using a standard press.
As each nut is installed, the nut’s clinching ring is embedded completely in the metal and locks the displaced metal behind a tapered shank. This ensures high push-out resistance, and the nut’s knurled platform embedded in the metal promotes high torque-out resistance.
The plated finish of the FusionLug is undisturbed during the installation process, and the reverse side remains flush, smooth and unencumbered.
"All that is required to mount the FusionLug to the board is a single mating screw for each nut," Bronk says. "With less hardware to stock, handle and install, our customers save time, money and effort."
In addition to their assembly benefits, the nuts offer quick and easy disassembly when a customer’s system requires service. Bronk says, "The nuts won’t fall out, and fewer parts keep service steps at a minimum. Our customers want captive hardware." Use of the threaded hardware also provides for the greatest amount of surface area, which keeps voltage as high as possible.
For more information on self-clinching nuts, call PEM Fastening Systems at 215-766-8853 or visit www.pemnet.com.