A typical no-no you must never do is to allow anything that can set off an arc flash. For instance, there are 2 medium-voltage fuse boxes that are exposed and open, and energized. Say these medium-voltage boxes are 10,000 volts VAC each. If the boxes are still energized, a spark from a probe when putting a probe up to a voltage not recommended by the electrical manufacturer of the probe, or dropping a silver-end screwdriver into the energized area may be enough to set off a dangerous arc flash or even arc blast.
A typical no-no you must never do is to allow anything that can set off an arc flash. For instance, there are 2 medium-voltage fuse boxes that are exposed and open, and energized. Say these medium-voltage boxes are 10,000 volts VAC each. If the boxes are still energized, a spark from a probe when putting a probe up to a voltage not recommended by the electrical manufacturer of the probe, or dropping a silver-end screwdriver into the energized area may be enough to set off a dangerous arc flash or even arc blast.