Were those
circuit breakers you encountered
turned to the off position, or were they
tripped? A
circuit breaker switch that's manually been turned off will be firmly in the off position. The
switch for a
circuit breaker that has been tripped will generally remain in the "On" position, but if you press the
switch gently toward the off position, the
switch will move without much force and will feel as if it isn't latched
in one position or the other.
If the
breaker has tripped, I would contact the contractor that sold you the
dimmer racks. There are troubleshooting steps you could take and that we could walk you through if we knew the manufacturer and model of your
dimmer racks, but in a brand new
system it's not your responsibility to do so. It's the contractor's. They are responsible for providing a
system design that will function without fault, and they are also responsible for confirming that the systems they've provided you were installed correctly by their installers, and that the systems are free of defects from the manufacturers.
You may feel like you're being a bother by contacting them, but as someone who works at a firm that offers contracting services, I assure you this is the best course of action. When we get calls about things not working, we may walk the users through some troubleshooting steps to weed out some of the simpler potential causes, but we always prefer checking the systems out ourselves. We have to assume when someone calls that the troubleshooting they've done is not valid, and that what they've described to us as the symptoms they're seeing could be completely inaccurate. The more we trust a client to do their own troubleshooting, generally the more time we spend on the phone trying to figure out exactly what they've tested so far, if the tests they did were valid, and if the results of those tests indeed tell us what the client thinks those results indicate.
Save yourself the headache and let the vendor/installer handle this under warranty.