Hazardous lighting - from safety to savings

Lighting in hazardous (classified) locations poses application challenges in class 1, division 2 areas that require improved temperature classes (T-ratings or T-codes). For instance, oil refineries classify numerous areas with a T3 temperature class rating. A 70-watt (W) high pressure sodium (HPS) light source achieves this rating. The often-preferred wattage of 100 or 150 typically obtains a T2A or T2B rating. The following pages explore the uses of restricted breathing to achieve a T3 rating. This maintains the proper approvals for safety, while producing cost savings associated with reduction of material, and subsequently installation costs. The authors reviews through a case study and project cost estimates, the savings and benefits achieved for a 175,000 barrel per day United States east coast refinery. The latter sections of this paper examine a lighting upgrade enlisting the newly available restricted breathing technology. The savings of 48% for reproducing the same illuminance or 24% for producing even and adequate lighting is illustrated by comparing the cost of this upgrade to estimates of upgrades not using restricted breathing. An estimate of a new installation saving 51% using restricted breathing is compared to one that does not. It is described in detail, how these estimates and savings were determined.