air conditioner fuse box replacement_mini cooper fuse box factory

16 2024-08

　　What is the relationship between Ih and It in the parameters of self recovering fuse products

　　PPTC stands for Polymer Positive Temperature Coefficient, which means high polymer positive temperature coefficient device in Chinese. It is a type of PTC thermistor.

　　When the current surge is too large or the temperature is too high, the resistance of the device will sharply increase, which can enter a high resistance state and achieve the effect of limiting the current.

　　After troubleshooting, the resistance value automatically recovers and returns to a low resistance state, so it is also called a self recovering fuse or a recoverable fuse. Product features, benefits, and disadvantages: limiting the current to a safe level, it can be repeatedly protected about 6000 times, does not need to be replaced, reduces the cost of guarantee and service, can be used with peace of mind, is easy to install, and is ideal for use in subtle situations.

　　PPTC has two current parameters, one is Ih, which is Ihold. It means holding the current, meaning that within this current, it remains inactive, also known as inactive current.

　　Another is It, which stands for Itrip, which is the action current. It means that to reach this current, action must be taken, also known as protective current. If the ambient temperature is around 25 ℃.

　　So at this point, It=2 * Ih. Generally, there is a 2-fold relationship between the current values of It and Ih, and the device is in a time where it may or may not operate because when the current increases and does not reach the operating current, the product will heat up. If the resistance deviates from the upper limit, it may be protected, but if it deviates from the lower limit, it will not be protected. It also depends on the product specifications and classification.