The maximum continuous current rating of a spring probe is determined by its design, size, and construction. Typical probes are rated from 2 to 8 amps maximum continuously current at working travel. While this is sufficient for most board test applications, higher current applications will require a much more solid and rugged probe to withstand current capabilities of 10 to 150 amps and beyond.
Another high current solution is our feed-through plunger probe line. As the name already describes, the plunger moves right through the probe and is made from a single piece, reducing the internal resistance of the probe to a minimum.
With increasing current, any resistance within the probe will generate heat. The higher the current the more heat is generated.
Another consideration is test cycle time. All probes are rated at continuously current carrying capability. During a test sequence the current might not be present all the time, giving the probe time to cool off and potentially being able to carry far more than the rated amps on the datasheet.