Sign & Digital Graphics

September '19

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ELECTRIC SIGNAGE 72 • September 2019 • S I G N & D I G I T A L G R A P H I C S lifetime modules you must have power supplies that are top-quality." When it comes to the voltage, "Life expectancy is no different in 12V versus 24V," says Riley. "Ideally the power sup- ply should last as long as the sign. The industry standard as far as warranty is still five years although there have been a few companies that have stretched that a bit further with limited warranties." Vincent agrees that there is no dis- cernable difference in the life of 12 V and 24V options, "Assuming the actual LED chip in the module is operated at its intrinsic voltage and the same power," he says. "There should be no lifetime or performance benefits to either design." Power Supply As addressed previously, the power supply is a critical element to the entire system. That said, sign makers should know what options are available with both 12V and 24V systems. "As far as manufacturers there are many options available in both 12V and 24V," says Riley. But when comparing one versus the other, "Typically there are more options commercially available in the sign indus- try at 12V versus 24V," Vincent shares. Again, 12V options pair well with channel letter projects so "With 12V, you could benefit when the sign doesn't require a substantial amount of lighting," says Bluhm. "Small channel letters that only need one power supply would be a good candidate for 12V LED products." Riley concludes that with "A UL Class 2 power supply you will be running an output of 60W or less on the 12V system and 96W or less on the 24V system." This brings us to the topic of "maxi- mum run" in relation to voltage. Maximum Run "Assuming the same efficiency, you can run 60 percent more modules per channel," states Vincent. "However, at Principal LED we have looked at compet- itive costs of a 24V, 96W single channel power supply, versus our 12V, 120W dual (2x60W) channel power supply, and the Making A Choice: Benefits When sign makers consult with customers before an LED design project or during the installation, many questions can come up regarding voltage, power supplies, costs and more. Here is a list, compiled by our expert sources, regarding the benefits of both 12V and 24V systems. 12V PROS SAFETY VINCENT: (An) advantage is that less than 15V is considered intrinsically safe, allowing for an automatic wet location safety rating. 12V also presents a lower spark hazard, which may be preferred around gas stations or areas with poten- tially flammable materials. FARMER: 12V is a safer voltage for DC circuits as opposed to any higher oper- ating voltages. COST AND RELIABILITY VINCENT: Lower cost power sources and more readily available from multiple sources. Highly reliable and a long history of performance in signage applications. RILEY: They are less expensive. The sign industry really wanted to get more standardized and has pretty much decided on 12V and 24V as an industry stan- dard after many years of different voltage packages entering the market. AVAILABILITY BLUHM: 12V is the standard for channel letter modules as the 12V, 60W power supply is readily available and cost less to manufacturer than 24V power supplies. In addition, a wider breadth of products is currently available in a 12V configura- tion. RILEY: Most sign systems run on 12V now. Most sign shops stock 12V for service and manufacturing. 24V PROS LONGER RUNS VINCENT: For long linear runs, 24V systems can be preferred, as the amount of voltage drop is often lower in a 24V versus a 12V system. Another benefit is in situations where the power supplies are mounted a long distance from the LEDs themselves, a lower gauge wire can often be used. FARMER: You can get a longer run of product with a 24V. Also, in some cases this means more intense light. RILEY: Longer runs. Really comes in play with LED border tubing when you have long 10-foot and 8-foot lengths and very long runs running around structures. MAXIMIZED POWER BLUHM: 24V products may utilize a higher wattage power supply that still conforms with Class 2 wiring. This 100W versus the 60W 12V power supply offers the user 40 percent more watts on a single power supply, which translates to more product on the power supply. VINCENT: Since UL allows 96W of power at 24V versus 60W of power at 12V on a single circuit, this can potentially reduce the number of units required on certain sign types. Although, it should be noted that there are many 12V, 120W and 180W units commercially available with multiple channels on the secondary side at 12V that can achieve the same result of limiting the number of primary hook-ups. COST REDUCTION FARMER: Using a 24V supply instead of a 12V supply greatly reduces the wir- ing cost to almost half the original cost. This is because increasing the voltage of a system causes a reduction in the current through it, and in turn reduces the size of the wires you need. The reduction in wire size cuts down the costs, as the thicker the wire the costlier it is.

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