The high power electrical switching properties of a polymer current limiter device are studied as a function of applied voltage. It is shown that a dramatic change in switching behavior occurs at a characteristic voltage. Below this voltage, the device switches to a high resistance state whereas at higher applied voltages it does not. It is shown that the high voltage, low resistance state has similar electrical characteristics to an arc discharge. Material variation experiments are also described which demonstrate that the changeover depends sensitively on the contact resistance between the filler particles of the composite material.