Leigh Marolf and Ron Weber, TE Intelligent Buildings
U.S. commercial businesses spend over $100 billion on energy annually with much of that consumption coming from building systems such as HVAC, lighting, security, elevators and fire protection. For example, in a commercial building, lighting alone can account for almost 35% of the total energy used. Experts estimate that greater use of smarter, energy-saving technology, such as in intelligent buildings –where all building systems are integrated and communicating with one another – could reduce this cost by $20 to $25 billion.
This need for energy efficiency is a driving force for industry change, and is particularly evident in areas such as commercial lighting where high-efficiency LED lighting is rapidly displacing inefficient, “traditional” incandescent light bulbs. A recent Navigant Research report projects the general commercial lighting market will grow from $2.7 billion in 2013 to more than $25 billion by 2021. The same report shows that the adoption of LEDs is not only fueling growth in the new build segment, but also in retrofits where LED based light sources are expected to jump from 5% of the market in 2013 to over 40% by 2017.
To capitalize on the market explosion, lighting manufacturers are looking for ways to increase their LED light source product offerings, and naturally, they are looking for ways to produce LED fixtures more affordably with more functionality. One area that is often overlooked in the design process is the importance of correct connector selection, and its significant impact on the overall cost of LED applications.
LED fixtures have unique requirements, which in all instances require power connections, but in other instances also require power and data connections. By considering connector selection in early design phases, designers have more choices, the possibility of custom solutions, and lower potential applied costs. Added benefits can sometimes include cost of materials and/or cost of assembly optimization, even long-term maintenance costs can be affected by making the product more serviceable with the right connector can significantly help making lighting more affordable and easier to apply.
How to Select the Right Connector
In selecting the best connector for an LED application, basic electrical, mechanical, and environmental performance requirements must be considered.
Electrically, the connector must be compatible with the current levels and voltages required by the intended application. Certainly, continuous voltage and current are basic considerations. In addition, other electrical-use conditions such as transient and surge conditions may occur over the life of the product that need to be identified and taken into account during the connector selection process.
Mechanical considerations can cover a broad range of features. As a result, the physical size of the connector relative to the application needs to be considered. Mating direction and how the connectors are held together after mating can also impact the selection process. Beyond these obvious form factor issues, the connector must also be evaluated relative to the end application for the degree in which it can withstand mechanical abuse, such as vibration and shock.
Environmentally, the connector must withstand both application temperature ranges and processing temperatures. The application environment will define additional needs, such as sealing, ability to withstand solvents or salt spray, high altitudes, or other extremes conditions. To ensure long-term, reliable connector performance in outdoor applications, UV exposure capability is also critical.
In high-intensity LED applications, the LEDs themselves generate enough heat to require careful consideration to thermal management—typically this is accomplished by a heat sink. The challenge of integrating thermal management into a system is an excellent example of why it is important to consider interconnections early in the design process.
All new high-intensity LEDs are small semiconductor devices that result in a highly concentrated thermal source. In some instances they are often packaged as surface-mount devices (SMD) and in other instances they are provided as arrays in chip-on-board assemblies. Integrating the connector system in amongst other LEDs, circuit boards, optics and thermal devices is often quite challenging if left to the end of the design process. Evaluation of the interconnect earlier in the design process provides for a more tightly integrated, optimized solution that can make assembly and repair much more efficient.
The Next Step in LED Connectors
As with any new revolutionary technology, the early introductory stages are characterized by a wide array of creative application options and possibilities as designers try to figure out how best to use the technology. In parallel, the marketers are constantly monitoring and probing the intended markets and customers to determine which options have traction and which don’t have interest. One simply needs to look at the cellphone industry during the early years to see how the bag phones eventually migrated to a wide array of brick phones, flip phones, PDA phones, etc. before the omnipresent and generally accepted touch-screen phones we now see everywhere.
LED lighting is going through a similar process. Arguably, we’re at the “flip phone” stage right now with multiple LED platforms available to the lighting user. Some of the earlier LED devices have already gone by the wayside and industry efforts at standardization have begun to yield fruit.
The most prominent of these is the TE’s ZHAGA configuration, which clearly defines mechanical and optical requirements for LED modules and provides a connectorized solution for LEDs. Figure 1 shows an example of the white ZHAGA holder in an exploded assembly view. Its central importance in providing the thermal, mechanical, electrical, and optical integration can be readily visualized from the exploded view.
Click image to enlarge
Figure 1. High-intensity ZHAGA® LED holder integrates thermal, mechanical, optical, and electrical management into a single, easy-to-use device.
The ZHAGA platform dramatically simplifies integrating LEDs into a fixture design by providing a standard footprint which offer designers an array of different LED options to integrate into their fixture designs. These standardized options inevitably afford the end customer a better, more flexible LED lighting fixture.
How Connector Selection Affects Cost
As consumer demand for more LED options grows and the lighting market continues to evolve, fixture designers and manufactures will no doubt create lights that burn brighter, last longer, and cost less to produce. Power, and in some instances data communications need to be provided to these new light sources. The benefits of early connector consideration are not going to be found so much in the acquisition cost of the connector, but rather the total applied costs and in some instances the life costs of the fixture.
Solid-state lighting systems with their increased longevity will demand equally robust connector systems since without reliable power connections, no LED will function. It is well acknowledged that the LEDs, thermal solution, optics, and packaging comprise a considerable part of the overall cost of the lighting system. It is sometimes ironic that the key component that makes all this work, the connector, is often considered an afterthought in the design process. When properly integrated, newer generations of application-specific connectors for lighting can reduce design integration time, optimize manufacturing/assembly, and make the end product more maintainable in the long run. In this context, making the decision to invest in the proper connector a very strategic one.
Without a reliable and appropriate connector system bringing power to the lighting fixture, it doesn’t matter how well designed and esthetically pleasing it is, if it is unlit it is useless. Spend some time and consideration selecting the appropriate proven connector system for the application even if it costs a little more. It will pay dividends in the long run.