We all have grown up with incandescent light bulbs that occasionally burn out. We pick up another one, replace it, and are back in business. Simple enough! Fluorescent lamps or bulbs, on the other hand, are quite different.
In 1987, I opened up a business in Valdosta, GA. For the first 7 years, I rented a couple of bays in a strip mall that had 8’ fluorescent lights. I was spending considerable time and money changing out the lamps and ballast. Since I was a small businessman, I could not afford to pay an electrician to maintain the fixtures. I did it myself. One day, while on the ladder changing out a ballast, a friend came in to see me. He watched, and we talked, as I continued to struggle with the task at hand. I was perturbed over my pet peeve, those fluorescent lights! I repeated a few choice words about the necessity of changing out the ballast, to which he responded, “Frank, if you would change your bulbs when they turn brown like that one (pointing at one of the lamps), rather than waiting until they turn black like that one over there, you wouldn’t burn out your ballast!” I stared in awe as I played back his statement in my mind, and responded, “Why do you know that and I don’t?” That was the beginning of my learning curve of lighting.
With my new enlightenment, I lost no time approaching my electrical supplier and friend, where I
purchased the lamps and ballast by the case. Upon presenting him with my newly acquired knowledge, I asked why he hadn’t informed me about changing the lamps out sooner. He promptly responded with half a smile, that he thought everyone knew that! The fact is that very few people know the truth about fluorescent lighting. Apparently the industry feels that they can sell more ballast if people don’t know about the “useful life” of the lamps.
So, here is “the rest of the story”. Traditional fluorescent lamps are manufactured to last approximately 3,000 hours. These are the “short life” lamps. At around 3,000 hours, the first burnout occurs, called cathode evaporation, showing up as definite browning on the ends of the lamps. This generally happens in about 6 months in a business where lights are burning for 8 hours a day, five days a week. In
businesses that operate longer hours, this can happen in 3 or 4 months. At this point, the visual lumens emitted by the lamp drops by 40 – 50%, so you only have a fraction of the lighting you had previously. The industry has failed to tell us that we are supposed to replace the lamps when they turn brown on the ends. If we don’t , it will cost us one way or another. Many large corporations, such as Sears, Belks and WalMart, have a maintenance team come in every 6 months to change out several thousand lamps at a time. During the change out, they feel the metal cover over the ballast. If it is unusually hot, they go ahead and change the ballast also. The alternative to a six month change out is to use long life, low mercury lamps.