This SAE Recommended Practice defines the test conditions, procedures, and performance requirements for P.T.C. overcurrent protection devices in amperage rating 30A or less. These devices are also typically rated with a maximum operating voltage, which for vehicular systems need to be 16 V (for 12 V systems)(, 32 V (for 24 V systems), and 58 V (for 42 V systems). P.T.C. devices are considered to be self-resetting after responding to overcurrent conditions and after such condition has been removed from the affected circuit containing the P.T.C.