It's common to put arcing horns on the HV side of a power transformer to short out voltage spikes arriving from lightning strikes along the line.
The question isn't correct, you have to define the voltage level not the power rating.
Some voltage must be present but the current causes the arcing.
A shorted coil or shorted coils in the rotor will cause arcing at the commutator. It should also be noted that if the brushes are damaged badly enough where they make contact with the commutator, this can cause arcing. Oh, and let's not forget that a stuck brush or brush spring will prevent a brush from making proper contact with the commutator. Arcing can result from that, too.
Arcing is electrical current jumping across a gap, or creating an arc, as in a spark plug firing, or lightning arcing across the sky.
They can have horns
horns
narwhals have horns
Horns.
yes they do have horns
The different types of horns commonly used in musical instruments are brass horns, woodwind horns, and natural horns. Brass horns include the trumpet, trombone, and French horn. Woodwind horns include the saxophone and clarinet. Natural horns are typically made from animal horns and are used in traditional and folk music.
Arcing horns (sometimes arc-horns) are projecting conductors used to protect insulatorson high voltage electric power transmission systems from damage during flashover. Overvoltages on transmission lines, due to atmospheric electricity, lightning strikes, or electrical faults, can cause arcsacross insulators (flashovers) that can damage them. The horns encourage the flashover to occur between themselves rather than across of the surface of the insulator they protect.[1] Horns are normally paired on either side of the insulator, one connected to the high voltage part and the other to ground. They are frequently to be seen on insulator strings on overhead lines, or protecting transformer bushings.The horns can take various forms, such as simple cylindrical rods, circular guard rings, or contoured curves, sometimes known as 'stirrups'.