Some voltage must be present but the current causes the arcing.
If a monopolar device is used and the patient return pad is incorrectly attached to the patient then arcing can occur between the pad and the skin which causes burning.
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.
Most common cause would be the plus wires. Dampness causes them to arc and the cylinder that the wire is arcing on won't fire causing a miss/sputter.
failure of excessive heat by radiation, conduction and convection, bearing failures or glass envelope breaking pitting of tungsten target, arcing, filament failure.
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.
high voltage breaking capacity
You have a wire that is loose and arcing.
Arcing at a switch contact is most likely caused by loose or corroded connections, excessive current passing through the switch, or a defective switch mechanism. These conditions can create an unstable electrical path, leading to arcing between the switch contacts.
Always push start your car.
An arcover is the unwanted arcing of electricity from one component to another.