Understanding LED inrush current and the financial impact on your lighting design – hortidaily.com
As more growers around the world implement LED lighting technology in their greenhouses, project managers and lighting strategists encourage them to gather all the facts about a fixture before making a short-term decision on a price that could cost more in the long run. A problem can arise if an electrical contractor designs a lighting project based around a specific LED fixture. If a grower finds a different LED fixture for the contractor to install, a redesign may be required to ensure compatibility between the facility design and the selected LEDs.
“Growers may end up paying more in total project costs because the specifications of the product purchased for the installation deviated from the product for which the project was designed. Perhaps they saw the lower price of a fixture and ran with it,” says Mark Pedersen, President/CEO, Climatrol Solutions Ltd., Surrey, British Columbia. “We want everything to run seamlessly, and it is very important with a lighting fixture that we have the complete information, just like any other component purchased for their facility. We need to be sure it is going to work for their greenhouse and not cause an issue to their electrical or hydro-electrical system.”
Complete fixture specifications are crucial
An important first step in a new facility design or redesign is to ensure your electrical contractor has a complete fixture specification sheet and application guide. This information will enable the project engineer to properly design the system. LED lighting manufacturers should make published specifications readily available that include operating voltage range, full load current at common operating voltages, rated input power, power factor, total harmonic distortion, operating frequency, and inrush current on startup. Often, growers assume that engineers can assess wattage and other technical factors simply based on fixture name or sight, which is not the case. Or a grower may not fully grasp the importance of the electrical design, of lesser-known technical specs.
Knowing these details from the beginning of the project ensures engineers can specify the proper cables, panels, high voltage sub feeds, and transformers, among other components. Without exact specifications, small deviations from the initial plan can add up to huge expenses and long delays during installation.
“Just the difference between 800 or 805 watts affects everything, and the more fixtures you have in your installation, the more it affects the design, including how many circuits are required or how far away the fixture is from the panel,” says Pedersen. “What I really value here is for companies like Signify, with their Philips brand, LED lighting, who have the team, and the engineers, to design where those features go.” While a difference of 5 watts may not seem like much, when you are installing 1,000, 10,000 or 25,000 fixtures, the “minor” wattage difference creates a significant deviation and major complications in a system.
Make sure to know the instantaneous power demand
“Matching the inrush current is particularly important,” says Evann Seney, Master Electrician, Honey Electric, Chatham, Ontario. Put simply, the inrush current value informs the electrician about the instantaneous power demand from a light. Inrush current has implications at the time of startup, in the event of power failure, and on the number of fixtures that can be switched on at the same time.
A fixture that has a very high inrush current can cause extensive issues in a lighting system, particularly if the circuits, cables, and transformers aren’t built to handle that load. A greenhouse system could have 150 to 200 lighting panels, all of which …….