Apologizes if this topic is covered elsewhere in the forum. If so, please point me in the right direction.
We are having some arc flash studies completed for buildings across our campus. The consultant is recommending that fuses be replaced with current limiting type fuses and also that breaker settings be dialed down to be more conservative. Adjusting our old breakers is something that we are nervous about doing and so I wanted some reactions from this group.
I know NFPA 70B has guidelines about exercising/cleaning breakers every couple of years but of course we, like every other building owner I have ever ran across, don’t regularly maintain our low voltage circuit breakers. We are not staffed to regularly clean & exercise the plethora of breakers across of 100+ buildings, nor do we have funds lying around to replace the vintage to middle aged breakers should they be discovered as prone to failure.
We are worried that by adjusting the breakers as recommended by the studies that we are asking for them to nuisance trip or perhaps malfunction in some unforeseeable way, causing widespread building outage or expensive parts replacements. Of course, if we run across breakers that are clearly on the their last leg or are an immediate threat to personnel they should be addressed right away. It’s those “dark horse” breakers that concern us.
Do folks have recommendations for what to do or have similar situations? Are there simple ways to inspect breakers to see if they appear to have useful service life remaining / can be exercised or adjusted without worry of problems in doing so? Any tips and tricks that don’t involve a lengthy outage to building power? What are your other large campus type clients doing in regards to maintenance and testing of breakers? Is this something anyone does that you are aware of?
Any feedback is appreciated. READ MORE
