Spot replacment v's full re-lamp

There are a variety of reasons to practice group relamping, in which a set of lamps is replaced at a scheduled time, rather than spot relamping, in which lamps are only replaced when they burn out. Most of these reasons apply to fluorescent and high-intensity discharge (HID) lamps rather than incandescents, which have much shorter lifetimes.

• Group relamping requires much less labour per lamp than spot relamping. A worker might take as long as a half hour to retrieve and install a single lamp. If all the materials were on hand for a large number of lamps, a worker could move systematically from fixture to fixture and cut the required time to about 2 minutes per lamp. The process would also be less disruptive, because group relamping is usually done outside working hours.

• Group relamping is easy to schedule and delegate to outside contractors, who have special equipment and training.

• Group relamping provides brighter and more uniform lighting because lamps are replaced before their output has fully depreciated.

• Direct energy benefits result as the ballast is not powering a blown or old lamp

• Group relamping offers increased control over the replacement lamps, reducing the chances of mixing incompatible lamps—such as those with different color temperatures.