Incomplete information provided. What is the voltage and what are the features provided with this breaker?
Can I assume that the voltage is 480v? If so can I also assume that you have ground fault as a part of the breaker?
Have you determined if the breaker is tripping because of an overload (thermally) and, as such, can not be reset immediately which my guess says that it is not.
If it can be reset immediately after a trip it most likely is tripping instantaneously. A 2000a breaker has an instantaneous setting, what is it set at? Who manufacturer the breaker? Is the trip unit solid state? Is it peak or RMS sensing? Peak sensing is more prone to nuisance trips and is found in older breakers before RMS sensing was available as a result if voltage spikes creating a current spike such as from capacitor switching.
If it has ground fault, what is the pick-up set at It should be adjustable from about 25%-100% with a max. setting of 1200a. If set lower, why? Breakers with adjustable setting are shipped with these setting in the lowest position and often not adjusted after installation. It is possible that the breaker is tripping because of a GF. If the pick-up setting is lower than the instantaneous pick-up of setting of the downstream breaker then the upstream breaker will trip. The same thing with the instantaneous adjustment that is usually adjustable from 50-100% is the trip unit rating of that breaker.
