PCA LAMPS 

We strongly recommend that the lamps are staggered evenly throughout the PCA oven for optimum curing results.  We also suggest that all lamps are replaced at the same time. A major SLA resin vendor says you should change at least every 2000 hours because the power will drop <70% or more at 2000 hours.
We have customers that change PCA bulbs every 1000 hours or every 6 months for best results.