Question 3: How Many Times Can a PPTC Operate Under Maximum Voltage and Inrush Current?

Each type of PPTC is designed for a specific operating voltage and can withstand a certain level of inrush current. According to UL standards, a PPTC must still exhibit the PTC effect after 6,000 operation cycles. For fuses used in communication equipment, it is required that after as few as a dozen to as many as hundreds of operations at maximum voltage, all performance parameters must remain within their original specified ranges.

Hardware designers should be aware that PPTC are intended for protection purposes and are not designed for applications where frequent repeated tripping is considered a normal operating condition.