Q: During a recent survey, the inspector cited us for not exercising our circuit breakers downstream of our generator. Does the LSC require annual exercising of all circuit breakers between the generator and the connected load?
A: The LSC section 9.1.3 does require emergency power generators to comply with NFPA 110 Standard for Emergency and Standby Power Systems, 1999 edition. Section 6-4.6 of NFPA 110 requires the main and feed circuit breakers between the generator and the transfer switch terminals to be exercised annually with the generator in the off position. This appears to me that all emergency source circuit breakers are required to be exercised annually. This would include the generator output breaker and all downstream distribution breakers, up to and including any breakers that feed the emergency feed side of the automatic transfer switch (ATS). I believe that would exclude any loads connected to the load side of the ATS such as motors, lights, pumps, etc. The process is a simple one because all affected breakers are normally in a de-energized state. I do not recall ever seeing a reason for this procedure published, although I’m sure there is a good reason. In my experience though, breakers that are not exercised regularly can be extremely (if not impossible) to reset, even though the internal trip mechanism may work perfectly. This may lead an organization to not conduct this annual test, which may result in them being cited for noncompliance. Some organizations will purchase replacement circuit breakers and have them available on a shelf in case the breaker will not reset. While this is a very proactive approach to testing and a quick response to potential repairs, it can be rather costly as the large current breakers are a bit pricey. While this issue may not come up very often during a survey, it is a LSC requirement and the surveyor has the obligation to cite the issue if he or she sees it as being noncompliant.