question

@missy, if you can provide some photos of the install, particularly the connections between the batteries and the breaker(s) and the Orion, that would be helpful.

What brand breaker is it that's tripping? There are a lot of knockoff-brand breakers out on Amazon and such places that are known for either tripping well below their rated current or well above, so basically if it isn't a Bussman breaker, that's very likely your problem. The other possibility, of course, is that there's a short somewhere in the wiring, like maybe a loose POS strand that's shorting out on the chassis and popping the breaker (as it should in that case).

Yet another possibility is that if your connections aren't tight or there's a bad crimp somewhere along the line, the wire would be heating up and since many DC breakers are thermal-trip, the heat in the line could be causing the breaker to trip... or, for that matter, even your underhood temperatures depending on where you have the breaker mounted... thus why, if you can, I ask that you update this post with as many photos of the actual installation as possible, as that will be a great help in diagnosing the condition :)