Respectfully - you have overshot the point, switching a 48 volt contactor coil that draws only 1A is next to trivial for a mains rated thermostat on a water heater ( these are usually >= 10A ac ).Inductance is only relevant for the maintenance of an arc with fluctuating impedance when dealing with DC. It's why old transformer-type DC welders and carbon arc power spplues used big chokes in series.
Beyond that, 30VDC is 30VDC. Two or three car batteries in series will sustain an arc.
Switching DC is no joke. That's why cars and trucks run on 12 or 24VDC, instead of 72 or 90VDC like locomotives - DC equipment gets much more bulky and expensive at higher voltages. E.G. a contactor rated for 40 horsepower at 600VAC will probably only handle 2-5 horsepower at it's maximum DC rating of 90~120VDC... if it even *has* a DC rating at all.
In fact the inductance of the line whether welder or otherwise serves to establish AND maintain the arc for DC systems - this is why we have to have an idea of the L in the line when designing breakers for an application.
2 or 3 car batteries in series will not sustain an arc if the series load ( read contactor coil ) limits the current to 1A - you will get a very small and very very temporary arc that will be hard to discern in daylight.
Posting worst case short circuit scenarios borders on the unhelpful