New York-based architectural lighting design firm H.M. Brandston & Partners recently had the chance to revisit a project it designed three decades ago, when an existing dimming system required a fast-track replacement. The firm was called in to troubleshoot by client Sage Realty after the burnout of a dimming system for lobby and ground-floor exterior lighting at 437 Madison Avenue in Manhattan, a multi-tenant office building.

"The existing dimming system self-immolated after three decades of constant use, and a new system needed to be put in place very quickly, because it is a public space with a lot of foot traffic," says Brandston project manager Richard Dorfman. "The replacement also had to be accomplished while the building was in use, and we had to program it all during normal business hours. First, we put a lot of torchieres in place for temporary lighting in the lobby, since it was an emergency situation. My role was to take the 30-year-old electrical drawings from Brandston's original lighting design and develop a breakdown of all the circuiting into a system of revamped zones. Basically, we had to incorporate the existing zones into a much more elaborate dimming system with far more capability."

To get new dimmer racks on-site within a one-week turnaround, the firm turned to Electronic Theatre Controls, Barbizon Electric Supply, and electrical contractor Municipal Electric. By the afternoon of the existing system's early-morning meltdown, principal lighting designer Howard Brandston met on-site with ETC's consultant Sonny Sonnenfeld, his former colleague from Century Lighting. Requirements were quickly mapped out, equipment orders approved by the client, and dimmer racks shipped within two days.

Brandston specified two full-size Sensor SR48 dimmer racks with 192 circuits, a Unison two-pushbutton station, a Unison LCD touch screen, and a Unison PC interface station, accompanied by an astronomical timeclock. "Fortunately, enough of the existing wiring was still intact, so the electricians were able to install the new dimming system in a pretty clean way," Dorfman says. "And the original lighting design, in terms of luminaires, was still performing well, so it didn't need to be changed. It was a nice exercise in seeing how a lighting design can hold up over the years."

In terms of dimming, "we were able to take something our firm completed way back when and tune it up by using smaller dimming units with much more flexibility in many more zones," Dorfman says. "You wouldn't have approached [the project] the same way back then. I believe the existing system was still using big, unwieldy auto-transformers." The upgraded dimming system features approximately 114 zones and incorporates about 20 cues for lighting changes at various times of day.

ETC field project coordinator Todd Reemtsma worked with Dorfman on programming the new dimming system. "We hooked up a laptop to do a lot of the changes to the system, which was programmed with Light Manager, a proprietary ETC software used with the Unison components," Reemtsma says. "The astronomical timeclock functions made it easy for the designers to do their programming. Rather than having a single preset coming up at a certain time of day, there is a whole series of presets linked together to create a subtle progression throughout the day."