Learning the hard way: What to do when hard wiring becomes a cost instead of a cost saving
September 17, 2013 by Jon DeSouza
Industrial connectors or hard wiring? It’s a debate design engineers continue to have, a subset of the larger showdown between integrated and modular design.
It’s often perceived as a conflict between the present and future: some OEMs characterize their customers as so price sensitive they will choose the lowest possible sticker price over a lower total cost of ownership throughout the service life of the machine. They believe connectors add to the up-front cost of their product, not realizing that, over time, connectors recover their cost and much more through ease of maintenance (with reduced downtime) and by facilitating the renewal or upgrading of machines, because sub-systems can be uncoupled and re-coupled in a fraction of the time it takes in a hard-wired environment.
OEMs might reply that it is not their job to educate the marketplace, or deny the customer what they want, which is not unreasonable. But connectorization can enable an OEM to increase profits, reduce time to market and deliver an improved and serviceable product to the end customer, differentiating a company from the competition. Converting from hard wiring to connector-based wiring can result in reduced workload, therefore removing sunk costs. This can be a game changer not only in profit dollars, but increased production and a more desirable product, as these North American manufacturers discovered.
A manufacturer of paper conveyors for commercial printing presses had been hard wiring more than 200 wires to the control box of each unit prior to final testing. During a benchmarking process, it was determined this process could take up to four work days per unit. Switching to six modular connector assemblies in a plug-and-play solution shaved up to 2½ days off the process. The new connector-based solution involved $1,400 in additional hardware, but saved almost two-and-a-half times as much in labour and other materials and helped the company increase its production rate.
A manufacturer of large, automated precision-welding machines was making hundreds of hard-wired connections in each of its units. It took a week to build and test one, then several days to dismantle it and another week to reassemble it at the customer’s location. Switching to a series of pluggable connectors cut wiring time dramatically, saving extensively on labour costs. Now, each step that used to take a full week is being done in less than a day, with savings well in excess of the cost of the connectors.
A builder of conveyor systems for the food and beverage sector needed to design an IP67-compliant product that could withstand harsh operating conditions like immersion in wash-down situations. It wanted to reduce install time and maintenance downtime as much as possible, and increase throughput by 15 per cent. Switching to a state-of-the-art connector accomplished all of those objectives, with the savings in install times accruing to its bottom line.
A maker of acoustic microscopes for analyzing the integrity of semi-conductors developed a model requiring 120 leads for powering processes, including different voltages. The design objective was a machine with a small footprint, but engineers ran out of space inside the machine for such an elaborate wiring distribution. Using two heavy duty connectors with 60 pins each to optimize space utilization solved the problem, achieving all design objectives while capturing net material cost savings—no wiring bundles as well as less metal paneling throughout.
Hard wiring can be a space-eater inside a machine, often leaving bundles of excess wiring, a wasteful practice. Designers can now avoid this by moving power termination to the connector. That’s a capability of today’s state-of-the-art, heavy-duty modular connectors: some require only male crimp contacts so the electrical feed per wire can supply up to five contacts by using a multiplier inside the connector. In that manner, the connector on the outside of the machine assumes a function that would previously have necessitated a separate terminal block inside.
Moreover, manufacturing equipment has become modular and upgradeable, which makes connector-based wiring even more appealing as it provides for easier integration and serviceability. Connector-based wiring allows for wire bundles to be pre-assembled and pre-tested, ensuring that when final assembly is completed there are no misconnections.
Occasionally, we hear of OEMs who considered switching to connectors many years ago and found it wasn’t worth the trouble. The fact is, however, the case for hard wiring never improves, but connectors continue to improve across the board. Manufacturers continue to produce new connectors that can be optimized for the specific application. A case in point: a maker of large, portable energy storage systems—400 storage drawers per truck container—transitioned years ago from hard wiring to a power connector which proved to be fragile and failure-prone. Moving this manufacturer to a modular blind mating docking system designed for direct panel mounting in drawer systems allowed the OEM to design a smaller drawer with a more compact electrical design. The manufacturer achieved connector cost savings by using a newly designed docking frame system. Significant space savings were realized by combining power, signal and data modules in a hybrid connector layout. Install times were reduced by 40 per cent, and the blind mating concept ensures a consistent termination that is incredibly durable.
Slim and compact connectors improve space utilization, as do hybrid connectors that can accommodate many combinations of power, signal, data, coax, polymer or glass fibre, Ethernet and even pneumatics. Some are optimized for outdoor use in all four seasons, even a Canadian winter. For decentralized automation scenarios, slim, secure push-pull connectors can feed multiple lines through compact spaces for data transmission and power supply in a PROFIBUS network typical of robotic applications in automotive welding and assembly lines. Heavy-duty connectors also are available for high heat, high current or hygienic applications, and with lower cost casings like glass-fibre reinforced plastics that give OEMs the full functionality of a heavy-duty modular connector at a lower price point than metal. Choosing the right product can achieve substantial cost savings that can help an OEM offer customers the best of both worlds—a competitive sticker price and attractive total cost of ownership.
Jon DeSouza is president and CEO of HARTING Canada, Inc. & HARTING Inc. of North America. To reach him, visit www.harting.ca.
This article originally appeared in the September 2013 issue of Manufacturing AUTOMATION.