Why do old fluorescent fixtures fail in high humidity?

[Buzz Bloom]

For some time now there has been a phenomenon in my home that I consider to be a mystery, since I do not understand it. I am hopeful that someone at this site may have a helpful suggestion.

My home was built in 1962, and the florescent light fixtures are the original hardware. Our kitchen has a set of six 40 inch fixtures, in two banks of three each. In humid conditions, mostly during the summer, the lights don't work. That is, with mild humidity just one light doesn't work, but with maximum humidity, none of the six work. Changing the bulbs has no effect. In the winter, when the air is dry, all of the lights work. This phenomenon began about 5 years ago.

Does anyone have any ideas about why humidity should affect the behavior of the light fixtures this way?

 

[DrClaude]

Most probably a problem with the ballast. If you Google "ballast humidity", you see you're not the only one with the problem! Installing a new one should help.

 

[Fervent Freyja]

Does the home still have the original cloth-covered wiring?

 

[Buzz Bloom]

Does the home still have the original cloth-covered wiring?

Hi Freyja:

Your question will take me a while to answer. I will need to move a stepladder from the garage up two flights of stairs to the kitchen on the second floor since the fixtures are about 8 feet above the floor. Can you explain why cloth-covered wiring is relevant to the humidity effect?

Regards,
Buzz

 

[Mark44]

Does the home still have the original cloth-covered wiring?

I doubt it, since the house isn't all that old.

My home was built in 1962