Works to spec
These heaters are obviously a some kind of excess stock being sold off from some appliance product. Their well made and work to specification. Using a lab power supply I see about 95W of power consumed at 24V steady-state. That's within the +-20% specification for these I've found elsewhere. If you're going to use these, you're expected to have then necessary clues so you don't burn something down. Small PTC heaters have high in-rush current when they're cold. Use a current limited supply and keep it low: 5A is enough. Heats up to steady state in <1 minute. You must fuse the circuit: don't toy with such things unfused. Also, they need airflow: they are designed to work with a fan, otherwise they won't reach full power, and too much heat will concentrate in the element, wire, etc. Read more