Per this charge controller’s specifications, it appears the input limit is 700W when charging a 12V battery system. Can the controller operate safely with four 320W panels connected in serial-parallel configuration for a combined 1280W, 87V, 17.6A input? I’ll eventually add a second controller in sync with the first to run two serial sets of panels to each, but want to squeeze as much power out of what I have in the meantime as possible. Of course want to confirm going over the 700W limit won’t cause dangerously excessive heat or other safety concerns
The output is a max 700W, since thats what 50A x 14V gives you. So thats not an input limitation.
The PV input has different limits. First of all 100V max, which is a hard limit. There has been plenty of MPPT burned due to too high input voltage.
Then you got the max Isc of 60A, which is not strictly a hard limit, however if you want to surpass that you need to provide external shortcircuit protection.
As long as you stay inside those two limits your MPPT will be fine.
If it can safely operate with your panels or not can not be judged since you did not provide the full panel datasheet.
You can use the MPPT calculator to determine if your config would be safe or not. Make sure to check “Allow for more than 130% overpanelling” if you want to put more PV onto a single MPPT