Abstract: Arc fault detector device (such as arc fault circuit interrupter) testing apparatus and methods including generating a true arc fault current by energizing a contact relay at a predetermined frequency, applying and regulating the true arc fault current to a detection device under test by selecting a load from a resistor bank that is coupled to the tested device, determining whether the device under test was able to detect the arc fault current. The invention is useful for determining whether an arc fault circuit interrupter is capable of tripping in response to an arc fault current.