Like JayleneSlide mentioned, those elements aren’t actually live as pictured, that’s the outer casing. But even if they were live, they wouldn’t arc at that distance.
A general rule of thumb for arc distance in air on earth is 1000V per 1mm. That means that each nut would have to be 0.24mm apart from each other (assuming 240v, it’d be 0.12mm or about 0.004 inches in a 120v country) to start arcing.
Once the arc starts, that distance can increase. This is because arcs will ionise the air, creating a lower conduction path for further arcing. This will continue until the hot ionised air rises away from the conduction path and gets too long to sustain the arcs.
But in any case, those nuts will never arc for a second reason; if they were live they would be dead shorted to each other anyway through the metal case that they’re bolted to.
Like JayleneSlide mentioned, those elements aren’t actually live as pictured, that’s the outer casing. But even if they were live, they wouldn’t arc at that distance.
A general rule of thumb for arc distance in air on earth is 1000V per 1mm. That means that each nut would have to be 0.24mm apart from each other (assuming 240v, it’d be 0.12mm or about 0.004 inches in a 120v country) to start arcing.
Once the arc starts, that distance can increase. This is because arcs will ionise the air, creating a lower conduction path for further arcing. This will continue until the hot ionised air rises away from the conduction path and gets too long to sustain the arcs.
But in any case, those nuts will never arc for a second reason; if they were live they would be dead shorted to each other anyway through the metal case that they’re bolted to.