Every extra step in a power supply install eats into the day, and building your own junction boxes in-house is one of the easiest places for that time to disappear. When the supply and the enclosure are sourced separately, someone on your crew is drilling holes, running wire, and testing connections before a sign ever gets mounted. Pre-wired power supply boxes are built to skip that step, so the real question is whether the labor saved is worth changing how your shop sources this one component. Grimco carries the Principal Sloan Qwik Box™ Slim, which is built for exactly that kind of shortcut.
Most electrical sign shops don't think of the power supply box as a bottleneck until they start timing it. Ordering the power supply and the enclosure as two separate line items means paying for two products and then paying labor to marry them together, whether that happens on the production floor, during install, or on a service call months later. For fabricators running lean crews or juggling several rebrand jobs at once, that assembly time adds up fast, and it's rarely the part of the job that actually differentiates one shop's work from another's.
The Qwik Box™ Slim ships ready to mount, with the wiring and switch already handled, so there's no on-site assembly left to do before it goes up. Principal Sloan backs it with a 10-year product and 5-year labor warranty, worth checking against the job if warranty terms matter for the client. Qwik Box Spec Sheet
The time savings show up most clearly in the field, not just in the shop. Installers working a service call in bad weather, or a crew trying to knock out several units back-to-back, feel the difference immediately when there's no in-box assembly left to do. The slim profile also matters in cabinets where space is already tight, and because the enclosure supports both single and double configurations, one product line can cover more of your job mix instead of stocking several different boxes.
Whatever pre-wired option you land on, confirm the UL classification covers the locations you're actually installing into. The Qwik Box™ Slim is UL Classified for dry, damp, and wet locations, but that rating still needs to match the install environment; a mismatch here is a code problem, not just a preference. It's worth pulling the datasheet before quoting a job where wet-location exposure is a factor.
The case for switching is strongest for shops that take on rebranding projects or seasonal pushes where volume spikes fast. Standardizing on a pre-wired, UL-listed enclosure lets your assemblers spend their time on the customization each job actually needs including cabinet work, face changes, and LED layout, instead of rebuilding the same power supply box over and over.