The costly installation mistake most contractors make
July 27, 2018 — While LED lighting upended the way many in the industry think about, work with and design lighting and controls, the installation of these low-voltage (less than 60Vdc) lighting systems still eerily mirrors the installation of their line-voltage predecessors.
This mismatch between the infrastructure power run to the fixtures and the power required by the low-voltage LEDs, sensors and wall stations has a material impact on both the man-hours and total installed cost of a lighting project. But a new solution in power distribution enables installers to more-effectively tailor the power provided throughout a lighting system while saving a considerable amount of time and money in the process.
The power mismatch
Consider a commercial office space or a K-12 school; not too long ago, when fluorescent troffers were the standard lighting fixture found in these buildings, an expansive infrastructure of line-voltage (Class 1) wiring was pulled from fixture to fixture, in conduit, throughout the space.These long runs of line-voltage power organized the fixtures and controls into hardwired branch circuits.
Once installed, the lighting could only be controlled in the configuration with which it was wired. There was no way to reorganize how the lights were grouped or controlled without physically rewiring them.
Today, LED lighting and control systems (occupancy sensors, day-light sensors, wallstations, etc.) have evolved into solutions that typically require low-voltage (Class 2) power wiring. The industry has addressed the new low-voltage power needs of the lighting and controls system with a kind of “worst-of-both- worlds” Band-Aid approach.
Contractors still pull line voltage to the low-voltage fixtures, which often contain AC-DC drivers that allow them to operate on a line-voltage circuit. Then, they overlay separate low-voltage controls wiring, so the lighting system satis es applicable energy codes and green building criteria.
Unfortunately, this practice creates lighting systems that showcase the least desirable traits of Class 1 and Class 2 wiring, minimizing any potential benefits. The pitfalls of this approach include:
• Maximizing material and labour-intensive Class 1 runs throughout a space.
• Establishing a rigid and hardwired lighting system structure.
• Restricting communications between low-voltage wiring and the control system.
• Separating lighting and controls wiring, even though both could be low-voltage.
The solution is low-voltage power
Low-voltage power for LED lighting controls systems offers a new approach to power distribution that more closely matches the needs of an energy code-compliant installation. The systems minimize the amount of line voltage pulled into the space and expands the low-voltage system to include both LED lighting fixtures and controls.
With low-voltage power, line voltage is pulled to low-voltage power modules distributed throughout the project. The modules provide low-voltage circuits for On/Off and dimming control of addressable low-voltage LED lighting fixtures.
It also coordinates the connected wallstations, daylight and occupancy sensors, and controlled receptacles. The low-voltage power for LED lighting controls enables contractors to pull line voltage only to areas where the low-voltage power modules are located, where they then create 300W or 600W low-voltage lighting systems using pre-terminated control cables.
The benefits of a better match
By better matching power distribution with the project’s low-voltage power requirements, contractors will see immediate benefits to their designs, bids and installations involving LED lighting and controls systems. Replacing Class 1 architectures (pipe and wire) with pre-terminated Class 2 cables reduces installation time by up to 40%. A project that would have taken 200 manhours to complete using the traditional installation method can now be completed in 120.
Contractors can get on and off jobs faster while leaving clients with a more flexible lighting and controls solution, because low-voltage power systems are addressable. Should the configuration of the space change, maintenance and facility teams can easily reconfigure the low-voltage power system with simple switches or a wireless remote control.
This is another important distinction between low-voltage power and the traditional line-voltage approach; the latter can only be reconfigured by physically going back into the ceiling and rewiring the system. Ultimately, the total installed cost of a flexible low-voltage system architecture is up to 20% lower than the installed cost of a comparable line-voltage system.
A power solution that addresses the poor fit between the traditional line-voltage circuit structure and the needs of low-voltage LED lighting systems is here today. Built to feature the benefits of both AC and DC wiring, low-voltage power offers a lighting system solution that is:
• Faster and easier to install
• Maintains electrical efficiency
• Offers more flexibility
• Is more cost-effective
Low-voltage power is the “best-of-both-worlds” solution for today’s LED lighting power distribution.
Chris Andrews is product manager, Low-Voltage Lighting & Control Systems, with Eaton’s Lighting Division.
This article originally appeared in the June 2018 issue of Electrical Business Magazine.
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