Capital and labor costs can vary widely in retrofits using tubular LEDs (TLEDs), which makes crunching the payback numbers difficult. Yes, the TLED itself is more energy efficient than a fluorescent lamp, but multiple configurations each have tradeoffs between labor and maintenance. Begin by sorting the four UL classifications for TLED products, and noting the advantages and drawbacks of each.
Type A TLEDs, the plug-and-play version, offer the simplest conversion and are rising in popularity. They contain internal drivers that operate on power from the existing fluorescent ballast. Type As do not require alteration of the fixture or wiring. Because they operate on the existing ballast, compatibility issues do arise. Each TLED manufacturer will list compatible ballasts and dimming capabilities, but even different generations of the same ballast could introduce a problem, according to Alex Truong, product manager, Lamps at MaxLite Inc. In addition, any installation, large or small, may have different ballast makes and models in the ceiling, installed over the years. MaxLite is willing to test customer-supplied ballasts for compatibility. “There are so many different variables to consider. You could build a product that will work with everything, but then it’s going to be very costly,” Truong said.
With Type A TLEDs, the multiplicity of lumen packages available is compounded by ballast factors. Just like fluorescents, TLEDs operating on a low‑ballast factor ballast will produce fewer lumens for fewer watts. The converse is also true: a high ballast factor can raise the consumption of a 16.5W TLED to 27W. The TLED spec sheet will show the different lumen packages and confirm that efficacy remains the same.
Depending on the age of the existing ballast, a long‑lived Type A TLED lamp could easily outlast. Maintenance personnel are more used to lamp failures and will often make a warranty inquiry for a failed TLED. “Did you test that fixture with a fluorescent lamp to make sure that the ballast didn’t fail?” asks Truong. “Typically it’s the ballast that fails first.” There is a theory that the lower wattage of the LEDs can lead to cooler operation that could extend the life of an electronic ballast. Nevertheless, some utility rebate programs require replacing all the ballasts in a retrofit. These additional labor and materials costs defeat the advantages of the plug‑and‑play product.
The Type B configurations were the most popular of early generations of TLEDs. Type Bs contain internal drivers that accept line voltage, requiring additional labor to rewire the fixture, bypassing the ballast (which may have to be removed and disposed of properly). There are two configurations of Type B: both line voltage and neutral are connected to one socket (requires a non-shunted socket) or line voltage at one end and neutral at the other. According to Truong, the double-ended configuration presents a shock hazard if power to the fixture is not cut during lamp installation. Some manufacturers, like Aleddra, offer a safety switch that will prevent the circuit from completing until the TLED is safely installed.
Type C TLEDs come with a separate driver that replaces the ballast, and they require new, low-voltage sockets. “This is probably the best way to go about a TLED retrofit,” said Truong. “You have an LED driver that’s designed to work with the LED product. There’s better compatibility. There’s less chance of a problem.” Because the driver is not sealed inside the 1 inch tube, the LEDs are isolated from heat produced by the driver, and vice versa.
This is the most expensive of the three configurations and the least popular, according to Truong. But a Type C’s driver may be more amenable to energy savings through dimming and other control options.
In comparing options, owners must look far into the future and predict the availability of specific replacement ballasts and drivers. Does the manufacturer offer a driver that can replace that failed ballast? Everywhere a customer installs a long-lived TLED, the existing components of the luminaire must be inspected: damaged interior finishes and degraded sockets, lenses or louvers could erode your light levels or present a safety hazard.
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An additional Hybrid TLED configuration (a.k.a. dual-tech, Type D or Type A/B) seems like the best of both worlds, but does raise red flags. Hybrid TLEDs will install as a plug-and-play (Type A), but when the ballast gives out, the fixture can be rewired and the lamp will operate as a Type B. Michael Myer, research analyst at Pacific Northwest National Laboratory, sees a problem with efficacy ratings. A utility rebates TLEDs in order to achieve persistent energy savings. If the lamp is rated with a ballast, what is the efficacy after conversion to line voltage? What is the rated life after conversion? Where the utility rebate program does not specify a configuration, a Hybrid TLED could possibly earn a rebate as a Type B but be installed as a Type A; or vice versa.
Truong’s main objections involve safety and labeling: “There’s no standard or regulation as far as how to label this product, and it can cause confusion in the marketplace.” A Hybrid product may have a safety label for one use and not for the other. After the ballast fails and the troffer is rewired for a Type B TLED (single- or double-ended), the electrician will apply stickers indicating the fixture’s changed UL certification. “After the installation, you’re probably throwing out all the instruction manuals and the stickers and anything that comes with the packaging. So if you want to swap it out later on when your ballast fails, you’re missing the warning labels.”
Mislamping could simply not work or cause a potential shock hazard, perhaps damaging the lamp and/or sockets.
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