This video documents a failure-mode experiment on a consumer-grade PTC plug-in heater, one of the types often marketed as a "Tesla heater." The experiment investigates the device's thermal behavior when its cooling fan is disabled, simulating a critical component failure, especially given the observed lack of a thermal fuse. The PTC element's power consumption rapidly decreased from an initial peak near 850W to a stable 53W, at which point the heater's temperature stabilized at approximately 240°C. A physical inspection confirmed the plastic housing did not melt or soften. The conclusion, as far as I can tell, is that the PTC heater's self-regulating property provides a significant degree of inherent safety, preventing thermal runaway in this specific failure scenario.
Safety Analysis of a Fanless PTC Heater
0:00 Experiment Setup: A "Tesla" branded plug-in PTC heater is tested with its fan removed to simulate a failure. The device notably lacks a dedicated thermal fuse, relying on the PTC element's characteristics for safety.
0:22 Initial Power-On and Observation: When activated, the heater's power consumption peaks above 850W before quickly dropping as the element heats up. The temperature is monitored as it climbs past 100°C.
1:40 Thermal Stabilization: The system stabilizes at a temperature of approximately 238-240°C. At this point, the power consumption has self-regulated down to a constant 53W.
2:06 Physical Inspection: After turning the power off, a physical check reveals the plastic housing remains hard and has not melted or softened, indicating it can tolerate the stabilized temperature, at least for a short duration.
2:22 Key Takeaway - Self-Regulation: The experiment demonstrates the inherent self-regulating nature of the PTC heater. In a fan-failure scenario, it limits its own temperature to a point the housing can withstand, preventing an immediate meltdown or fire.