Equipment Life Expectancy
What is considered the average life of electrical equipment such as switchboard circuit breakers and fused switches? I have done a search but have not found any previous discussions on this topic.
There are so many variables that I don't know that there is anything such as an "expected life" of electrical equipment. There are many electrical systems in place that are more than 50-years old that are still performing adequately and there are probably some that were installed last week that should be replaced. Some of the variables are:
The environment in which the equipment is installed (damp basement, or nice, dry, climate controlled room?)
The quality of the original equipment (was it a good recognized brand for which replacement parts are still available, or the cheapest junk that was available at the time?)
How heavily is the equipment loaded.
The workmanship of the installer (were connections properly torqued, etc.)
Has the installation been properly maintained?
Has the use of electricity increased and is the equipment still adequate for today's electrical load?
I don't think anyone could make a blanket statement that any electrical system over ?? years old should be replaced. Each installation will need to be evaluated on its own merits.
...agreement with haskindm
I agree with the last post citing numerous factors that affect electrical equipment life.
I recently surveyed a 50 year-old mothballed substation with oil-filled circuit breakers in a clean building - that I recommended transformer and breaker oil sampling - directed at reuse of the old substation.
The older equipment tended to be overbuilt - which lent itself to longevity.
I think there was a safety factor in older equipment that far exceeded the standard for today's equipment.
If I had to pick an age for standard use, good environment equipment longevity, I'd say 35 years - but there's nothing hard and fast about that.
this article may help
a friend posted this article about transformers, and one interesting note was that most power transformers in operation today are >42 years old, i was
searching for information on life expectancy also.
we have some power xfmrs and switches that are >30 yrs.
I have worked on breakers from the 1920's that have been maintaned well and were still in good working condtion and passed all testing. I have also seen neglected equipment fail testing after 5 years. Breakers are like cars, baby them and they last forever (I believe that the older stuff was built better), neglect them with no maintenance and the life expetancy drops quickly.
There is an IEEE matrix somewhere (Red book I think) that lists the average life expectancy of power dist equipment)