In "reality" the system would be designed to dump those surges into suppressors. Think giant giga-ohm resistor blocks. These would heat up and that heat would have to be removed.
The isolators would be a last line of defense, if the surge overwhelms the system the isolator would work to prevent that power from arcing from the console to Ensign Weatherbee's crotch.
In "dramatic reality" we need the explosions on screen to remind us How Fucking Serious the situation is.