Lamp Failure Rates

All manufacturer provide an hourly life rating on there lamps. I have not as of yet seen any manufacturer give a life rating of indefinitely. I would say the potential for failure of any or all of your fluorescent lamps is 100%. I do not think that the area that the light illuminates has any bearing on lamp life. I do know that the condition of the ballast may greatly reduce lamp life. I all so know that it is general practice to just replace the lamp that failed. This gets you into vicious cycle which seem like you are all ways replacing the lamps. If a lamp fails in a light that has multiple lamps in it replace them all. Life is much easier that way. You can get a general knowledge of how long you get on a re lamp. If the lamps life is unusually short then you can make ballast replacement. I have the lamps changed out in all the office areas together at the first signs of one failing. This is about ever two years.

Hello ruro0302

The causes of unscheduled lamp failure are generally over-voltage/voltage spikes, or faulty ballasts.

If the building has it's own transformer, check the automatic tap-changer on the HV side, (Get your Electricity Supply Authority to do that), as these sometimes intermittently fail.

In a factory situation, Variable-Speed Drives, Welders and other electrical equipment may place Voltage Spikes on the Power Mains, leading to early lamp failure, and other equipment damage.

In many large enterprises: Factories, hotels, Warehouses and the like, lamps are replaced on a scheduled basis, whether a particular lamp has actually failed or not.

Once this scheduled replacement system is set up, it is rare for a customer or user to see a failed lamp.

The lamps which are recovered, and were still working at the time of being recovered, are placed in separate containers, then they may be used in easy-access-for-replacement areas, or donated to worthy causes.

Kind Regards....

Are your lamps T6, T8, or T12 or CFL?

Typically, the higher the Kelvin Rating (temperature) the whiter color of the lamp. Check the bulbs label.

If your have occupancy sensors on the fixture the earlier the lamp will fail. The On/Off cycle of these type of fixtures contribute to early failure of the lamp, not voltage spikes. Our manufacturing enviornment has over 500 Variable freauency drives for motors. We have data that indicates failures do not occur with respect to harmonics or any other transient voltage conditions. We are lucky to get one year from a T8 lamp at 5000 kelvin in one of these fixtures.

CFL (Compact Flourescent Lamps) are subject to the same conditions. However this style of lamp does not burn at the same temperature as T style lamps. These lamps usually fail due to the enviroment they are housed in (the fixture) and the surrounding temperature (indoors/outdoors) but due last longer. We can see several years of life from a CFL outdoors before failure.

The lamps will work best if left in the on condition as long as possible (on at night, off at dawn). High kelvin lamps burn 2 to 3 times hotter than the surface temperature of the sun.

Hope this helps.

If you have the specific lamps number most of the big 3 companies (Phillips, GE or Sylvania) should have a life rating on the specs. If you find a lamp has a rating of 10,000 hours this means that if you have 100 of these lamps and run them at the perfect temperature with perfect voltage and ideal switching 1/2 of the lamps will have failed after 10,000 hours. They also offer long life versions as replacements but frequent switching, bad voltage and high temperature still shorten the life.

Are you looking for information to base a lamp replacement schedule on?

Some predominately office facilities replace lamps wholesale periodically and spot replace critical fixtures on demand.

One chain of well known retailers replace all of the lamps in every store as the technician covers his territory. Those that fail are left till his next round.