Two general comments on this. 1) Any decent power supply will have current limiting to protect itself so you shouldn't be able to overload it and kill it. It should protect itself. A supply may not be able to handle an overload indefinitely though. 2) For powering up a new installation I would suggest a power supply that has an adjustable current limit. That way if you have a wiring error you won't just melt the wiring it will shut down and you can investigate further. Power supplies with a 30A output need to be used very carefully since they can destroy wiring, wiring harnesses and etc. Sure once once you have checked your sub-circuits and powered up the equipment separately then they can be used, but always with an awareness that they can also cause damage.