“The average molded light string submerged in three feet of salt water will usually fail in one day. Our light strings with NxG construction can last for months submerged.”
—Jason Loomis, owner and founder of S4 Lights
Jason Loomis is an owner and founder of S4 Lights and the head of product development. An inventor with a degree in mechanical engineering, Loomis created NxG because he saw a need in the market for a better-made decorative light string that would conquer the issues caused by water ingress and perform better than the industry standard.
“I knew if I came up with a better version, I’d have success,” he said. “Basically, we set out to make a better mousetrap, as they say.” It took eight years for the innovative NxG construction to reach the market.
We spoke with Loomis about the rigorous testing NxG undergoes — above and beyond UL standards — to ensure that decorative lights strings made with NxG construction are highly water resistant, have low current leakage, few failures, and a longer life than other strings on the market. NxG is truly an innovation and an evolution that benefits designers and installers, and, ultimately, enhances the consumer experience.
Q: What were the issues you found with decorative light strings that were on the market?
A: There was a lot of corrosion, electrolysis, wire breakdown, GFCI tripping and light string failure. The main cause of the issues is water ingress. It’s the enemy of outdoor light strings. My solution was an epoxy-filled husk that is complementary to the U.S. market, which would protect the vulnerable connections — the exposed wire and soldered joints — in the light string construction.
Q: What kind of testing do you do to make sure the NxG product will work as promised?
A: We put decorative light strings with NxG construction through rigorous tests. We try to break it and find out its limits. First, there are UL [Underwriter Laboratory] product standards that are already established and have to be met:
- Temperature cycling. We put the lights in testing equipment that acts like both an oven and a freezer to see if the product breaks down.
- A string pull or strain test, which is just like it sounds. A machine pulls the string until it comes apart; at the break point it registers the amount of force needed to do that.
- The crush test in which you take a heavy weight, maybe 30 pounds, and drop it on the plug to make sure it doesn’t smash open, which would mean you’ve got exposure to high voltage. You do the same to the husks, the plugs and the sockets to make sure they can withstand an industry-established force without coming completely apart.
- The lumen degradation test which requires that we burn the LED for thousands of hours and measure the light output. LEDs become less bright over time, but we use a very high-quality LED that actually gets brighter in the first 500 hours and then starts to degrade very slowly compared to what you’ll find in the marketplace. This is why we can offer a four-season warranty.
- After a year, regular strings may have lost half their brightness. It’s difficult to see degradation, but once you install a brand-new string next to an old one it’s obvious. Our LEDs last longer.
- Leakage Tests to see how much current is escaping from the light string; ours is up to four times less than traditional molded construction.
- The most important test, however, is the one for ingress protection or IP. The UL has minimum requirements of meeting IP44.
We do internal testing at our manufacturing facilities or with independent labs so we know they will exceed UL standards, before we send the products to UL.
Q: Tell us more about the water ingress, IP, test.
A: We put our light strings into a glass water chamber that’s about as tall and wide as a phone booth. High pressure jets shoot fresh water at the light strings from all sides for about 30 minutes. We want to exceed UL’s IP standard and get to at least an IP rating of 66. The higher the IP number the more watertight the product. Sixty-eight is generally the highest rating.
To meet it, water is sprayed for three minutes at 100 liters/minute at a distance of one meter (three feet). This is like hurricane force water. We look for water ingress and damage, as well.
We also do a submersion test using salt water since many of our installations are in places like Florida, where they can be affected by salty ocean air. Salt water is more corrosive. The light string is submerged in one meter of water until it fails.
Q: What does the IP rating mean?
A: It means the light string can stay under one meter of water for 30 minutes and not fail. The average molded light string submerged in one meter of salt water will fail in one day. Light strings made with our NxG epoxy-filled husk construction can last for months submerged. Although it’s not something we’d ever tell anyone to do, you could essentially turn on the light under the water and let it go.
The testing goes beyond immersion, though. There’s also positive water pressuretrying to get into vulnerable areas such as the connectors and bulb husk.
And we don’t do any of this for UL. We do this test because we want to take our product to the next level. We really want to see how waterproof this thing is.
Q: Do you do other tests not required by UL?
A: UV testing, for one. We expose the light string to UV [ultraviolet] radiation to see how the material degrades and how the product performs. You’ve probably seen discolored headlights. UV breaks down plastic and makes it crack and weaken. With our lights, we’re looking to see if UV will cause the lenses to turn a yellow color and the wire to degrade.
Our lights are constructed this way: The LED itself is encapsulated in an epoxy resin, which is technically the lens. Over that is a clear wide-angle polycarbonate lens cap. We use a high-quality epoxy and polycarbonate with UV inhibitors added so our lights don’t yellow.
Q: Why is water ingress performance ultimately the most important issue to deal with?
A: A light string that lets in water will have increased current leakage. That’s going to cause the GFCIs (ground fault circuit interrupters) to trip, which is a massive headache for light string users and installers. If you’ve got a theme park and the light strings are causing the GFCIs to trip, you’re paying someone to go out and reset them.
Our light strings have a high IP rating, which means it’s watertight and has low current leakage. In fact, light strings with our NxG construction have three to four times less leakage than a light string with a traditional molded husk construction. That means fewer GFCI tripping failures and happy customers not spending extra time and money on labor to reset.
Q: Any last thoughts?
A: I want customers to know that that our production of NxG is automated. Some parts of the production of today’s light strings with a traditional molded husk construction are not automated. That’s a throughput bottleneck and requires increased labor needs. Automation reduces cost and improves consistency — meaning fewer defects — in NxG. Ultimately, S4 Lights’ NxG provides a better performing light string at a comparable cost to the competition.