Positive Temperature Coefficient Overcurrent Protection Devices (PTCs)(STABILIZED Dec 2014)
This SAE Recommended Practice defines the test conditions, procedures, and performance
requirements for PTC (positive temperature coefficient of resistance) overcurrent protection devices.
PTCs are typically either polymeric (PPTC) or ceramic (CPTC). It is important to note battery voltages
versus powernets/system voltage versus max battery voltages: (12 V/14 V/16 V, 24 V/28 V/32 V, and
36 V/42 V/58 V). All voltages are DC. These devices are typically rated with a maximum operating
voltage, which for vehicular systems need to be 16 V (for 12 V batteries), 32 V (for 24 V batteries), and
58 V (for 36 V batteries/42 V powernets). PTC 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 PTC.