Immersion heater PTC heating element VS alloy resistance heating element

- Mar 02, 2020-


      Immersion heater PTC heating element VS alloy resistance heating element

PTC means positive temperature coefficient which can control the temperature automatically. As a good effective heating element, PTC heating element is popular used in different field heaters. Following we will talk about the immersion PTC heating element used in water heater.

The traditional electric immersion heating element normally uses alloy heating resistance wire. While the resistance value of this type of heater is constant, the power of the heater remains basically unchanged when the power is turned on. So when the heater is in operation, once the liquid level is lower than the heater, the heat generated by the heater is too late to be taken away, which will cause the temperature of the heater to rise rapidly, and the surface of the heater may even become red and shiny. So normally when use the resistance heating element, we will also add a temperature control for safety.

The PTC heating element, actually inside is using a PTC ceramic plate as the heating source for the liquid heater. When the PTC liquid heater is connected to the power supply, even if the liquid level is lower than the heater, the heater itself will not appear red and shiny. This is because the resistance value of the PTC ceramic heating chip changes with temperature, and the higher the temperature, the smaller the resistance value. When the liquid level drops and the heater is exposed to the air, the heat dissipation rate of the heater decreases, and its own temperature becomes higher and higher. Due to its own PTC effect, the resistance value will become larger and larger, according to P = U2 / R, the power becomes lower and lower correspondingly, and eventually reaches a certain temperature when the temperature reaches a certain temperature, and the temperature no longer rises.

Now more and more field and applications are using PTC immersion heating elements to replace the alloy resistance heating element.