With more and more growers worldwide using LED lighting in their greenhouses, they are advised by project managers and LED experts to gather all the facts about a luminaire before making a short-term decision on the price that will benefit them. more in the long run could cost. Signify warns that if the electrician makes a lighting design based on one specific LED luminaire, a problem may arise. When the grower subsequently buys another LED luminaire, it may be necessary to redesign it to ensure compatibility between the plant design and the selected LEDs.
“Growers may then end up paying more for the total project cost because the specifications of the purchased product for installation differ from the product the project is designed for. They may have seen the lower price of a fixture and have moved on,” he said. Mark Pedersen. President / CEO of Climatrol Solutions, British Columbia, Canada. “We want everything to be hassle-free, and with a light fixture it is very important that we have all the information, just like any other part purchased for their plant. We need to be sure that it will work for their greenhouse and not cause problems for their electrical system or hydropower plant. “
Full luminaire specifications are essential
An important first step in the design, or redesign, of a new installation is to ensure that the electrician has the complete specifications and application instructions for the luminaire. This information will enable him to make a proper design of the system. LED lighting manufacturers shall provide published specifications that include the operating voltage range, rated current at rated line voltage, rated input power, power factor, total harmonic distortion, operating frequency, and starting current. Breeders often assume that technicians can judge watts and other technical factors based on the name of the fixture or by sight, which is not the case, Signify says. Or perhaps a breeder does not understand the importance of lesser known technical specifications for electrical design.
Knowing these details from the start of the project allows engineers to specify the appropriate cables, panels, high voltage wiring and transformers in addition to the other components. Without the exact specifications, minor deviations from the original plan can lead to high costs and large delays during installation.
“Just the difference between 800 or 805 watts has a big effect on everything, and the more luminaires you have in your setup, the more it affects the design, including how many circuits it takes or how far the luminaire is from the panel. removed, “says Pedersen. “What I really appreciate here are companies like Signify, with their Philips LED lighting that has the engineers and team to decide in the design where these features will go.” Although a 5 watt difference may not work much, this “small” watt difference can cause considerable variance and major complications in an installation of 1,000, 10,000 or 25,000 luminaires.
Make sure you know the power rises
“It’s important to consider the starting current,” says Evann Seney, master electrician at Honey Electric, Ontario, Canada. In short, the starting current informs the electrician of the current peaks required by the luminaires when they are switched on. The starting current has an effect on reactivation of the luminaires, in the event of a power failure and on the number of luminaires that can be switched on at the same time.
A luminaire with a very high starting current can cause major problems in a lighting system, especially if circuits, cables and transformers are not built to handle that load. A greenhouse installation can have 150 to 200 light panels, all of which need to be adjusted – at significant cost – if the starting current is higher than specified.
Certain drivers for LED luminaires will actively control the luminaire’s starting current at start-up. In these cases, the starting current is negligible. “All of our products are designed with our proprietary drivers,” said Chris Strom, Application Engineer for Signify North America, manufacturer of Phillips LED products. “One of the most important things we have built into the drivers is low starting current. Many shelf drivers and even advanced drivers have high starting currents, which affects the load on the system.”
It is important to consider what effect the activation profile will have on the system protection (such as switches and fuses). A circuit correctly dimensioned for a luminaire with a negligible or nominal load can be tripped at start-up if it is not designed for a higher starting current.
The incorrect starting current between the luminaire and the panel also means that the controller will shut down individual panels in the event of a power failure or in the event of a power failure throughout the network. And that, in turn, makes fuses blow. Multiple problems can occur if power is restored and all fixtures are turned on again at the same time.
Seney says, “If the lights were turned off in the event of a power outage, one hour in each panel would shift it, so when the power comes back on, you would turn on one panel at a time.” In addition, if the starting current of a luminaire is significantly higher than expected, the installer may install up to four timers and then turn on the lighting panel in four sections instead of one. “The electrician needs to know this in advance so it doesn’t happen until you’ve installed everything,” he says. “It’s a big expense.”
Do not spend money unnecessarily on your transformer
For example, missing or incorrect information or specifications about luminaires can also lead to unnecessary costs for transformers. For example, if an engineer is considering a fixture that draws 848 watts and the manufacturer chooses a fixture that draws 840 watts, the installer may install a transformer more than they need, or a transformer with a higher voltage than necessary. .
“It could mean you designed your transformer for 80% load and it only has 70% load,” Seney explains. “So if you look at the whole plant, you could have saved one 2.5 MVA transformer instead of a 2.75 MVA transformer. The difference from a 2.5 MVA transformer to a 2.75 MVA transformer is about $ 20,000 Canadian dollars. “
The costs are multiplied by the associated costs such as cables, concrete foundation and electrical panels. “It is more expensive to install. It is a heavier cable; it adds more weight, which means you need more braces in the structure to support the weight of the load on the superstructure,” says Pedersen.
Both experts emphasize that it is crucial to get the correct specifications for the switch-on current and other important technical factors, as otherwise the project risks unplanned costs. “It’s a contagious effect because everything else has to be bigger now. In the end, it’s all in vain, as no one wants the extra cost of going back and adding new furniture,” Seney says. costs resulting from not having the correct data. “
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