How to choose PTC heating elements

- Feb 23, 2021-

How to choose PTC heating elements

The characteristics and quality of PTC heaters are the key factors that directly determine the performance of PTC heater products. The current PTC heating elements used in thermostatic heater products such as heaters are all high-temperature PTC elements. The Curie temperature is higher than 120°C. Compared with low-temperature PTC elements, there are big differences in manufacturing process and performance parameters. Good PTC characteristics are the basis for obtaining good heating performance.

The main parameters to consider when selecting PTC heaters:

1.Room temperature resistance R25: used for 110~220V voltage, R25 is generally 100Ω~10KΩ, when used for 6~24V, R25 is 0.5~5Ω. Under normal circumstances, R25 is small, the initial current is large, the heating is fast, and the power is also large. But the withstand voltage capability is poor.

2.The Curie temperature PTC should be moderate: Under certain conditions, increasing PTC can increase the power consumption of the heater, but too high PTC (greater than 260°C) makes the electrodes of the PTC element prone to aging, significantly shortening the service life, and often Accompanied by thermal breakdown. So generally choose PTC heating element with Curie temperature below 260℃.

3. Withstand voltage should be high: at least two times the working voltage should be guaranteed to prevent electrical breakdown.

4.The temperature coefficient of resistance should be large: generally greater than 14 to ensure that it is less affected by environmental temperature changes.

5.The initial impulse current should be moderate: Generally, the impulse current should be less than twice the value of the stable working current.

6.The shape is flat and the thickness tolerance is within ±0.02mm.